Assertion: Density is a derived physical quantity. Reason: Density cannot be derived from the fundamental physical quantities.

If the assertion and reason both are false.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: Radar is used to detect an aeroplane in the sky Reason: Radar works on the principle of reflection of waves.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: Now a days a standard metre is defined as in terms of the wavelength of light. Reason: Light has no relation with length.

If the assertion and reason both are false.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: Avogadro number is the number of atoms in one gram mole. Reason: Avogadro number is a dimensionless constant.

If the assertion and reason both are false.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: Linear mass density has the dimensions of [M1L?1T0]. Reason : Because density is always mass per unit volume.

If the assertion and reason both are false.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: The time period of a pendulum is given by the formula, \[T=2\pi \sqrt{g/l}\]. Reason: According to the principle of homogeneity of dimensions, only that formula is correct in which the dimensions of L.H.S. is equal to dimensions of R.H.S.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: In\[y=A\sin (\omega \,t-kx),\]\[(\omega t-kx)\]is dimensionless. Reason: Because dimension of \[\omega =[{{M}^{0}}{{L}^{0}}T].\]

If the assertion and reason both are false.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: Out of three measurements l = 0.7 m; l = 0.70 m and l = 0.700 m, the last one is most accurate. Reason: In every measurement, only the last significant digit is not accurately known.

If assertion is true but reason is false.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: The graph between P and Q is straight line, when P/Q is constant. Reason: The straight line graph means that P proportional to Q or P is equal to constant multiplied by Q.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: When we change the unit of measurement of a quantity, its numerical value changes. Reason: Smaller the unit of measurement smaller is its numerical value.

If the assertion and reason both are false.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: The quantity \[(1/\sqrt{{{\mu }_{0}}{{\varepsilon }_{0}}})\] is dimensionally equal to velocity and numerically equal to velocity of light. Reason: \[{{\mu }_{0}}\] is permeability of free space and \[{{\varepsilon }_{0}}\]is the permittivity of free space.

If assertion is true but reason is false.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: Force cannot be added to pressure. Reason: Because their dimensions are different.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: Units of Rydberg constant R are m?1 Reason: It follows from Bohr?s formula \[\bar{v}=R\left( \frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}} \right)\], where the symbols have their usual meaning.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Assertion: Parallex method cannot be used for measuring distances of stars more than 100 light years away. Reason: Because parallex angle reduces so much that it cannot be measured accurately.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

If assertion is false but reason is true.

Two masses connected by a mass less spring .are placed on a horizontal smooth surface. The spring is initially compressed by 3 cm. The system is released from rest. The velocity (in m/s) of the 2 kg mass, when spring attains natural length is to

\[\sqrt{3}B=\left( 1/5\text{ }x\text{ }30 \right)\]

Two blocks A and B of masses m and 2m placed on a smooth surface are travelling in opposite directions with velocities of 6 m/s and 4 m/s respectively. A perfectly elastic spring is attached to block A. If after collision, velocity of A is \[\frac{2}{3}\,\,m/s\] towards right , then velocity of block B would be

\[\frac{4}{3}\,m/s\] towards left

\[\frac{16}{3}\,m/s\] towards left

\[\frac{28}{3}\,m/s\] m/s towards left

A vessel is partly filled with a liquid. Coefficients of cubical expansion of material of the vessel and liquid are \[{{\gamma }_{V}}\] and \[{{\gamma }_{L}}\] respectively. If the system is heated, then volume unoccupied by the liquid will necessarily

decrease if \[{{\gamma }_{V}}={{\gamma }_{L}}\]

remain unchanged if \[{{\gamma }_{V}}={{\gamma }_{L}}\]

increase if \[{{\gamma }_{V}}={{\gamma }_{L}}\]

decrease if \[{{\gamma }_{V}}={{\gamma }_{L}}\]

The value of Planck's constant is [CBSE PMT 2002]

\[6.63\times {{10}^{34}}J/\sec \]

\[6.63\times {{10}^{-34}}J\text{-}\sec \]

\[6.63\times {{10}^{34}}J/\sec \]

\[6.63\times {{10}^{-34}}kg\text{-}{{m}^{2}}\]

\[6.63\times {{10}^{34}}kg/\sec \]

Match List-I with List-II and select the correct answer using the codes given below the lists [SCRA 1994] List-I List-II I. Joule A. Henry \[\times \] Amp/sec II. Watt B. Farad \[\times \] Volt III. Volt C. Coulomb \[\times \] Volt IV. Coulomb D. Oersted \[\times \] cm E. Amp \[\times \] Gauss F. \[Am{{p}^{2}}\] \[\times \] Ohm

Codes: \[I-A,\,II-F,\,III-E,\,IV-D\]

Unit of self inductance is [MP PET 1982]

\[\frac{Volt\times metre}{Coulomb}\]

\[\frac{Newton-second}{Coulomb\times Ampere}\]

\[\frac{Joule/Coulomb\times Second}{Ampere}\]

\[\frac{Volt\times metre}{Coulomb}\]

\[\frac{Newton\times metre}{Ampere}\]

One second is equal to [MNR 1986]

1650763.73 time periods of \[Kr\] clock

652189.63 time periods of \[Kr\] clock

1650763.73 time periods of \[Cs\] clock

9192631770 time periods of \[Cs\] clock

Unit of Stefan's constant is [MP PMT 1989]

\[J\,{{m}^{-2}}{{s}^{-1}}{{K}^{-4}}\]

A suitable unit for gravitational constant is [MNR 1988]

\[kg\text{-}\,m{{\sec }^{-1}}\]

\[N\,\,{{m}^{2}}\,k{{g}^{-2}}\]

Out of the following pair, which one does not have identical dimensions? [AIEEE 2005]

Moment of inertia and moment of force

Angular momentum and Planck's constant

Assertion: Avogadro number is the number of atoms in one gram mole. Reason: Avogadro number is a dimensionless constant.

If the assertion and reason both are false.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

Assertion: ?Light year? and ?Wavelength? both measure distance. Reason: Both have dimensions of time.

If the assertion and reason both are false.

If both assertion and reason are true and the reason is the correct explanation of the assertion.

If both assertion and reason are true but reason is not the correct explanation of the assertion.

If assertion is true but reason is false.

If the assertion and reason both are false.

383 + Mcqs in Physics in NEET Page 7 McqOptions

301.	Assertion: Density is a derived physical quantity. Reason: Density cannot be derived from the fundamental physical quantities.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» D. If the assertion and reason both are false.

Discussion

302.	Assertion: Radar is used to detect an aeroplane in the sky Reason: Radar works on the principle of reflection of waves.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion.

Discussion

303.	Assertion: Now a days a standard metre is defined as in terms of the wavelength of light. Reason: Light has no relation with length.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» D. If the assertion and reason both are false.

Discussion

304.	Assertion: Avogadro number is the number of atoms in one gram mole. Reason: Avogadro number is a dimensionless constant.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» D. If the assertion and reason both are false.

Discussion

305.	Assertion: Linear mass density has the dimensions of [M1L?1T0]. Reason : Because density is always mass per unit volume.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» D. If the assertion and reason both are false.

Discussion

306.	Assertion: The time period of a pendulum is given by the formula, \[T=2\pi \sqrt{g/l}\]. Reason: According to the principle of homogeneity of dimensions, only that formula is correct in which the dimensions of L.H.S. is equal to dimensions of R.H.S.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» F.

Discussion

307.	Assertion: In\[y=A\sin (\omega \,t-kx),\]\[(\omega t-kx)\]is dimensionless. Reason: Because dimension of \[\omega =[{{M}^{0}}{{L}^{0}}T].\]
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» D. If the assertion and reason both are false.

Discussion

308.	Assertion: Out of three measurements l = 0.7 m; l = 0.70 m and l = 0.700 m, the last one is most accurate. Reason: In every measurement, only the last significant digit is not accurately known.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» C. If assertion is true but reason is false.

Discussion

309.	Assertion: The graph between P and Q is straight line, when P/Q is constant. Reason: The straight line graph means that P proportional to Q or P is equal to constant multiplied by Q.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion.

Discussion

310.	Assertion: When we change the unit of measurement of a quantity, its numerical value changes. Reason: Smaller the unit of measurement smaller is its numerical value.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» D. If the assertion and reason both are false.

Discussion

311.	Assertion: The quantity \[(1/\sqrt{{{\mu }_{0}}{{\varepsilon }_{0}}})\] is dimensionally equal to velocity and numerically equal to velocity of light. Reason: \[{{\mu }_{0}}\] is permeability of free space and \[{{\varepsilon }_{0}}\]is the permittivity of free space.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» C. If assertion is true but reason is false.

Discussion

312.	Assertion: Force cannot be added to pressure. Reason: Because their dimensions are different.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion.

Discussion

313.	Assertion: Units of Rydberg constant R are m?1 Reason: It follows from Bohr?s formula \[\bar{v}=R\left( \frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}} \right)\], where the symbols have their usual meaning.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion.

Discussion

314.	Assertion: Parallex method cannot be used for measuring distances of stars more than 100 light years away. Reason: Because parallex angle reduces so much that it cannot be measured accurately.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» B. If both assertion and reason are true but reason is not the correct explanation of the assertion.

Discussion

315.	Two springs of force constant 100 N/m and 150 N/m are in series as shown. The block is pulled by a distance of 2.5 cm to the right from equilibrium position. What is the ratio of work done by the spring at left to the work done by the spring at right.
A.	\[\frac{3}{2}\]
B.	\[\frac{2}{3}\]
C.	0.2
D.	None of these
Answer» B. \[\frac{2}{3}\]

Discussion

316.	A simple pendulum with a bob of mass 'm' oscillates from A to C and back to A such that PB is H. If the acceleration due to gravity is 'g', then the velocity of the bob as it passes through B is
A.	zero
B.	\[2\,gH\]
C.	\[mgH\]
D.	\[\sqrt{2gH}\]
Answer» E.

Discussion

317.	A certain system has potential energy given by the function \[U(x)=-a{{x}^{2}}+b{{x}^{4}}\]with constants, a, b > 0. Which of the following value of x is an unstable equilibrium point?
A.	0
B.	\[\sqrt{a/2b}\]
C.	\[-\sqrt{a/2b}\]
D.	\[\sqrt{a/b}\]
Answer» B. \[\sqrt{a/2b}\]

Discussion

318.	A block of mass m is pulled by a constant power P placed on a rough horizontal plane. The friction coefficient between the block and the surface is \[\text{I}{{\text{F}}_{\text{3}}}\]. Maximum velocity of the block will be
A.	\[\frac{\mu p}{mg}\]
B.	\[\frac{\mu mg}{p}\]
C.	\[\mu mgp\]
D.	\[\frac{p}{\mu mg}\]
Answer» E.

Discussion

319.	A body of mass 1 kg initially at rest explodes and breaks into three fragments of masses in the ratio 1 : 1 : 3. The two pieces of equal mass fly off perpendicular to each other with a speed of 30 m/sec each. What is the velocity of the heavier fragment?
A.	\[10\sqrt{2}\,m/s\]
B.	\[15\sqrt{2}\,m/s\]
C.	\[5\sqrt{2}\,\,m/s\]
D.	\[20\sqrt{2}\,\,m/s\]
Answer» B. \[15\sqrt{2}\,m/s\]

Discussion

320.	Two masses connected by a mass less spring .are placed on a horizontal smooth surface. The spring is initially compressed by 3 cm. The system is released from rest. The velocity (in m/s) of the 2 kg mass, when spring attains natural length is to
A.	\[\sqrt{\frac{3}{2}}\]
B.	\[\sqrt{\frac{2}{3}}\]
C.	\[\frac{3}{2}\]
D.	\[\sqrt{3}B=\left( 1/5\text{ }x\text{ }30 \right)\]
Answer» B. \[\sqrt{\frac{2}{3}}\]

Discussion

321.	Two blocks A and B of masses m and 2m placed on a smooth surface are travelling in opposite directions with velocities of 6 m/s and 4 m/s respectively. A perfectly elastic spring is attached to block A. If after collision, velocity of A is \[\frac{2}{3}\,\,m/s\] towards right , then velocity of block B would be
A.	\[\frac{4}{3}\,m/s\] towards left
B.	\[\frac{16}{3}\,m/s\] towards left
C.	\[\frac{28}{3}\,m/s\] m/s towards left
D.	4 m/s towards left
Answer» D. 4 m/s towards left

Discussion

322.	During the compression of the spring, the net work done on the block is
A.	Positive
B.	Negative
C.	Zero
D.	Cannot say
Answer» C. Zero

Discussion

323.	The specific heat of a substance varies with temperature \[t({}^\circ Q)\]as \[c=0.20+0.14t+0.23{{t}^{2}}\](cal/g/ C) The heat required to raise the temperature of 2 g of substance from \[5{}^\circ C\]to \[15{}^\circ C\]will be
A.	24 cal
B.	56 cal
C.	82 cal
D.	100 cal
Answer» D. 100 cal

Discussion

324.	A vessel is partly filled with a liquid. Coefficients of cubical expansion of material of the vessel and liquid are \[{{\gamma }_{V}}\] and \[{{\gamma }_{L}}\] respectively. If the system is heated, then volume unoccupied by the liquid will necessarily
A.	remain unchanged if \[{{\gamma }_{V}}={{\gamma }_{L}}\]
B.	increase if \[{{\gamma }_{V}}={{\gamma }_{L}}\]
C.	decrease if \[{{\gamma }_{V}}={{\gamma }_{L}}\]
D.	none of the above
Answer» C. decrease if \[{{\gamma }_{V}}={{\gamma }_{L}}\]

Discussion

325.	The unit of Planck's constant is [RPMT 1999; MP PET 2003; Pb. PMT 2004]
A.	Joule
B.	Joule/s
C.	Joule/m
D.	Joule-s
Answer» E.

Discussion

326.	The value of Planck's constant is [CBSE PMT 2002]
A.	\[6.63\times {{10}^{-34}}J\text{-}\sec \]
B.	\[6.63\times {{10}^{34}}J/\sec \]
C.	\[6.63\times {{10}^{-34}}kg\text{-}{{m}^{2}}\]
D.	\[6.63\times {{10}^{34}}kg/\sec \]
Answer» B. \[6.63\times {{10}^{34}}J/\sec \]

Discussion

327.	Which of the following is not the unit of energy [MP PET 2000]
A.	Calorie
B.	Joule
C.	Electron volt
D.	Watt
Answer» E.

Discussion

328.	Match List-I with List-II and select the correct answer by using the codes given below the lists [NDA 1995] List-I List-II Distance between earth and stars 1. Microns Inter-atomic distance in a solid 2. Angstroms Size of the nucleus 3. Light years Wavelength of infrared laser 4. Fermi 5. Kilometres
A.	Codes a b c d 5 4 2 1
B.	3 2 4 1
C.	5 2 4 3
D.	3 4 1 2
Answer» C. 5 2 4 3

Discussion

329.	Match List-I with List-II and select the correct answer using the codes given below the lists [SCRA 1994] List-I List-II I. Joule A. Henry \[\times \] Amp/sec II. Watt B. Farad \[\times \] Volt III. Volt C. Coulomb \[\times \] Volt IV. Coulomb D. Oersted \[\times \] cm E. Amp \[\times \] Gauss F. \[Am{{p}^{2}}\] \[\times \] Ohm
A.	Codes: \[I-A,\,II-F,\,III-E,\,IV-D\]
B.	\[I-C,\,II-F,\,III-A,\,IV-B\]
C.	\[I-C,\,II-F,\,III-A,\,IV-E\]
D.	\[I-B,\,II-F,\,III-A,\,IV-C\]
Answer» C. \[I-C,\,II-F,\,III-A,\,IV-E\]

Discussion

330.	Unit of self inductance is [MP PET 1982]
A.	\[\frac{Newton-second}{Coulomb\times Ampere}\]
B.	\[\frac{Joule/Coulomb\times Second}{Ampere}\]
C.	\[\frac{Volt\times metre}{Coulomb}\]
D.	\[\frac{Newton\times metre}{Ampere}\]
Answer» C. \[\frac{Volt\times metre}{Coulomb}\]

Discussion

331.	One second is equal to [MNR 1986]
A.	1650763.73 time periods of \[Kr\] clock
B.	652189.63 time periods of \[Kr\] clock
C.	1650763.73 time periods of \[Cs\] clock
D.	9192631770 time periods of \[Cs\] clock
Answer» E.

Discussion

332.	Curie is a unit of [CBSE PMT 1992; CPMT 1992]
A.	Energy of g-rays
B.	Half life
C.	Radioactivity
D.	Intensity of g-rays
Answer» D. Intensity of g-rays

Discussion

333.	Unit of Stefan's constant is [MP PMT 1989]
A.	\[J\,{{s}^{-1}}\]
B.	\[J\,{{m}^{-2}}{{s}^{-1}}{{K}^{-4}}\]
C.	\[J\,{{m}^{-2}}\]
D.	\[J\,s\]
Answer» C. \[J\,{{m}^{-2}}\]

Discussion

334.	\[1kWh=\] [AFMC 1986; SCRA 1986, 91]
A.	\[1000W\]
B.	\[36\times {{10}^{5}}J\]
C.	\[1000J\]
D.	\[3600\,J\]
Answer» C. \[1000J\]

Discussion

335.	\[Par\sec \] is a unit of [SCRA 1986; BVP 2003; AIIMS 2005]
A.	Distance
B.	Velocity
C.	Time
D.	Angle
Answer» B. Velocity

Discussion

336.	\[Ampere-hour\] is a unit of [SCRA 1980, 89; ISM Dhanbad 1994]
A.	Quantity of electricity
B.	Strength of electric current
C.	Power
D.	Energy
Answer» B. Strength of electric current

Discussion

337.	If the unit of length and force be increased four times, then the unit of energy is [Kerala PMT 2005]
A.	Increased 4 times
B.	Increased 8 times
C.	Increased 16 times
D.	Decreased 16 times
Answer» D. Decreased 16 times

Discussion

338.	One million electron volt \[(1\,MeV)\] is equal to [JIPMER 1993, 97]
A.	\[{{10}^{5}}eV\]
B.	\[{{10}^{6}}eV\]
C.	\[{{10}^{4}}eV\]
D.	\[{{10}^{7}}eV\]
Answer» C. \[{{10}^{4}}eV\]

Discussion

339.	The unit of reduction factor of tangent galvanometer is [CPMT 1987; AFMC 2004]
A.	Ampere
B.	Gauss
C.	Radian
D.	None of these
Answer» B. Gauss

Discussion

340.	Volt/metre is the unit of [AFMC 1991; CPMT 1984]
A.	Potential
B.	Work
C.	Force
D.	Electric intensity
Answer» E.

Discussion

341.	Density of wood is \[0.5gm/cc\] in the CGS system of units. The corresponding value in MKS units is [CPMT 1983; NCERT 1973; JIPMER 1993]
A.	500
B.	5
C.	0.5
D.	5000
Answer» B. 5

Discussion

342.	In \[S=a+bt+c{{t}^{2}}\]. \[S\] is measured in metres and \[t\] in seconds. The unit of \[c\] is [MP PMT 1993]
A.	None
B.	\[m\]
C.	\[m{{s}^{-1}}\]
D.	\[m{{s}^{-2}}\]
Answer» E.

Discussion

343.	One femtometer is equivalent to [DCE 2004]
A.	\[{{10}^{15}}\,m\]
B.	\[{{10}^{-15}}\,m\]
C.	\[{{10}^{-12}}\,m\]
D.	\[{{10}^{12}}\,m\]
Answer» C. \[{{10}^{-12}}\,m\]

Discussion

344.	Which does not has the same unit as others [Orissa PMT 2004]
A.	Watt-sec
B.	Kilowatt-hour
C.	eV
D.	J-sec
Answer» E.

Discussion

345.	A suitable unit for gravitational constant is [MNR 1988]
A.	\[kg\text{-}\,m{{\sec }^{-1}}\]
B.	\[N\ {{m}^{-1}}\sec \]
C.	\[N\,\,{{m}^{2}}\,k{{g}^{-2}}\]
D.	\[kg\,m\,{{\sec }^{-1}}\]
Answer» D. \[kg\,m\,{{\sec }^{-1}}\]

Discussion

346.	The resistance R =\[\frac{V}{i}\] where V= 100 \[\pm \]5 volts and i = 10 \[\pm \]0.2 amperes. What is the total error in R
A.	0.05
B.	0.07
C.	0.052
D.	\[\frac{5}{2}\]%
Answer» C. 0.052

Discussion

347.	Out of the following pair, which one does not have identical dimensions? [AIEEE 2005]
A.	Moment of inertia and moment of force
B.	Work and torque
C.	Angular momentum and Planck's constant
D.	Impulse and momentum
Answer» B. Work and torque

Discussion

348.	Assertion: Avogadro number is the number of atoms in one gram mole. Reason: Avogadro number is a dimensionless constant.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
Answer» D. If the assertion and reason both are false.

Discussion

349.	Assertion: ?Light year? and ?Wavelength? both measure distance. Reason: Both have dimensions of time.
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
Answer» D. If the assertion and reason both are false.

Discussion

350.	Dimensions of coefficient of viscosity are [AIIMS 1993; CPMT 1992; Bihar PET 1984; MP PMT 1987, 89, 91; AFMC 1986; CBSE PMT 1992; KCET 1994; DCE 1999; AIEEE 2004; DPMT 2004]
A.	\[M{{L}^{2}}{{T}^{-2}}\]
B.	\[M{{L}^{2}}{{T}^{-1}}\]
C.	\[M{{L}^{-1}}{{T}^{-1}}\]
D.	\[MLT\]
Answer» D. \[MLT\]

Discussion

Explore topic-wise MCQs in NEET.

Assertion: Density is a derived physical quantity. Reason: Density cannot be derived from the fundamental physical quantities.

Assertion: Radar is used to detect an aeroplane in the sky Reason: Radar works on the principle of reflection of waves.

Assertion: Now a days a standard metre is defined as in terms of the wavelength of light. Reason: Light has no relation with length.

Assertion: Avogadro number is the number of atoms in one gram mole. Reason: Avogadro number is a dimensionless constant.

Assertion: Linear mass density has the dimensions of [M1L?1T0]. Reason : Because density is always mass per unit volume.

Assertion: The time period of a pendulum is given by the formula, \[T=2\pi \sqrt{g/l}\]. Reason: According to the principle of homogeneity of dimensions, only that formula is correct in which the dimensions of L.H.S. is equal to dimensions of R.H.S.

Assertion: In\[y=A\sin (\omega \,t-kx),\]\[(\omega t-kx)\]is dimensionless. Reason: Because dimension of \[\omega =[{{M}^{0}}{{L}^{0}}T].\]

Assertion: Out of three measurements l = 0.7 m; l = 0.70 m and l = 0.700 m, the last one is most accurate. Reason: In every measurement, only the last significant digit is not accurately known.

Assertion: The graph between P and Q is straight line, when P/Q is constant. Reason: The straight line graph means that P proportional to Q or P is equal to constant multiplied by Q.

Assertion: When we change the unit of measurement of a quantity, its numerical value changes. Reason: Smaller the unit of measurement smaller is its numerical value.

Assertion: The quantity \[(1/\sqrt{{{\mu }_{0}}{{\varepsilon }_{0}}})\] is dimensionally equal to velocity and numerically equal to velocity of light. Reason: \[{{\mu }_{0}}\] is permeability of free space and \[{{\varepsilon }_{0}}\]is the permittivity of free space.

Assertion: Force cannot be added to pressure. Reason: Because their dimensions are different.

Assertion: Units of Rydberg constant R are m?1 Reason: It follows from Bohr?s formula \[\bar{v}=R\left( \frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}} \right)\], where the symbols have their usual meaning.

Assertion: Parallex method cannot be used for measuring distances of stars more than 100 light years away. Reason: Because parallex angle reduces so much that it cannot be measured accurately.

Two springs of force constant 100 N/m and 150 N/m are in series as shown. The block is pulled by a distance of 2.5 cm to the right from equilibrium position. What is the ratio of work done by the spring at left to the work done by the spring at right.

A simple pendulum with a bob of mass 'm' oscillates from A to C and back to A such that PB is H. If the acceleration due to gravity is 'g', then the velocity of the bob as it passes through B is

A certain system has potential energy given by the function \[U(x)=-a{{x}^{2}}+b{{x}^{4}}\]with constants, a, b > 0. Which of the following value of x is an unstable equilibrium point?

A block of mass m is pulled by a constant power P placed on a rough horizontal plane. The friction coefficient between the block and the surface is \[\text{I}{{\text{F}}_{\text{3}}}\]. Maximum velocity of the block will be

A body of mass 1 kg initially at rest explodes and breaks into three fragments of masses in the ratio 1 : 1 : 3. The two pieces of equal mass fly off perpendicular to each other with a speed of 30 m/sec each. What is the velocity of the heavier fragment?

Two masses connected by a mass less spring .are placed on a horizontal smooth surface. The spring is initially compressed by 3 cm. The system is released from rest. The velocity (in m/s) of the 2 kg mass, when spring attains natural length is to

During the compression of the spring, the net work done on the block is

The specific heat of a substance varies with temperature \[t({}^\circ Q)\]as \[c=0.20+0.14t+0.23{{t}^{2}}\](cal/g/ C) The heat required to raise the temperature of 2 g of substance from \[5{}^\circ C\]to \[15{}^\circ C\]will be

A vessel is partly filled with a liquid. Coefficients of cubical expansion of material of the vessel and liquid are \[{{\gamma }_{V}}\] and \[{{\gamma }_{L}}\] respectively. If the system is heated, then volume unoccupied by the liquid will necessarily

The unit of Planck's constant is [RPMT 1999; MP PET 2003; Pb. PMT 2004]

The value of Planck's constant is [CBSE PMT 2002]

Which of the following is not the unit of energy [MP PET 2000]

Match List-I with List-II and select the correct answer by using the codes given below the lists [NDA 1995] List-I List-II Distance between earth and stars 1. Microns Inter-atomic distance in a solid 2. Angstroms Size of the nucleus 3. Light years Wavelength of infrared laser 4. Fermi 5. Kilometres

Unit of self inductance is [MP PET 1982]

One second is equal to [MNR 1986]

Curie is a unit of [CBSE PMT 1992; CPMT 1992]

Unit of Stefan's constant is [MP PMT 1989]

\[1kWh=\] [AFMC 1986; SCRA 1986, 91]

\[Par\sec \] is a unit of [SCRA 1986; BVP 2003; AIIMS 2005]

\[Ampere-hour\] is a unit of [SCRA 1980, 89; ISM Dhanbad 1994]

If the unit of length and force be increased four times, then the unit of energy is [Kerala PMT 2005]

One million electron volt \[(1\,MeV)\] is equal to [JIPMER 1993, 97]

The unit of reduction factor of tangent galvanometer is [CPMT 1987; AFMC 2004]

Volt/metre is the unit of [AFMC 1991; CPMT 1984]

Density of wood is \[0.5gm/cc\] in the CGS system of units. The corresponding value in MKS units is [CPMT 1983; NCERT 1973; JIPMER 1993]

In \[S=a+bt+c{{t}^{2}}\]. \[S\] is measured in metres and \[t\] in seconds. The unit of \[c\] is [MP PMT 1993]

One femtometer is equivalent to [DCE 2004]

Which does not has the same unit as others [Orissa PMT 2004]

A suitable unit for gravitational constant is [MNR 1988]

The resistance R =\[\frac{V}{i}\] where V= 100 \[\pm \]5 volts and i = 10 \[\pm \]0.2 amperes. What is the total error in R

Out of the following pair, which one does not have identical dimensions? [AIEEE 2005]

Assertion: Avogadro number is the number of atoms in one gram mole. Reason: Avogadro number is a dimensionless constant.

Assertion: ?Light year? and ?Wavelength? both measure distance. Reason: Both have dimensions of time.

Dimensions of coefficient of viscosity are [AIIMS 1993; CPMT 1992; Bihar PET 1984; MP PMT 1987, 89, 91; AFMC 1986; CBSE PMT 1992; KCET 1994; DCE 1999; AIEEE 2004; DPMT 2004]