12583 + Mcqs in Physics Page 196 McqOptions

9751.	Forces \[{{F}_{1}}\] and \[{{F}_{2}}\] act on a point mass in two mutually perpendicular directions. The resultant force on the point mass will be [CPMT 1991]
A.	\[{{F}_{1}}+{{F}_{2}}\]
B.	\[{{F}_{1}}-{{F}_{2}}\]
C.	\[\sqrt{F_{1}^{2}+F_{2}^{2}}\]
D.	\[F_{1}^{2}+F_{2}^{2}\]
Answer» D. \[F_{1}^{2}+F_{2}^{2}\]

Discussion

9752.	Two small conducting spheres of equal radius have charges \[+10\mu C\] and \[-20\mu C\] respectively and placed at a distance \[R\] from each other experience force \[{{F}_{1}}\]. If they are brought in contact and separated to the same distance, they experience force \[{{F}_{2}}\]. The ratio of \[{{F}_{1}}\] to \[{{F}_{2}}\] is [MP PMT 2001]
A.	1 : 8
B.	? 8 : 1
C.	1 : 2
D.	? 2 : 1
Answer» C. 1 : 2

Discussion

9753.	The temperature of hot and cold end of a \[20cm\] long rod in thermal steady state are at \[{{100}^{o}}C\] and \[{{20}^{o}}C\] respectively. Temperature at the centre of the rod is [MP PMT 1996]
A.	\[{{50}^{o}}C\]
B.	\[{{60}^{o}}C\]
C.	\[{{40}^{o}}C\]
D.	\[{{30}^{o}}C\]
Answer» C. \[{{40}^{o}}C\]

Discussion

9754.	Two conducting spheres of radii 5 cm and 10 cm are given a charge of \[15\mu C\] each. After the two spheres are joined by a conducting wire, the charge on the smaller sphere is [AMU (Engg.) 2001]
A.	\[5\ \mu C\]
B.	\[10\mu C\]
C.	\[15\mu C\]
D.	\[20\mu C\]
Answer» C. \[15\mu C\]

Discussion

9755.	The ionisation energy of hydrogen atom is 13.6 eV. Following Bohr's theory, the energy corresponding to a transition between the 3rd and the 4th orbit is [CBSE PMT 1992; DPMT 2000; RPMT 1999; AMU (Med.) 2001]
A.	3.40 eV
B.	1.51 eV
C.	0.85 eV
D.	0.66 eV
Answer» E.

Discussion

9756.	The ratio of the wavelengths for 2 ® 1 transition in Li++, He+ and H is [UPSEAT 2003]
A.	1 : 2 : 3
B.	1 : 4 : 9
C.	4 : 9 : 36
D.	3 : 2 : 1
Answer» D. 3 : 2 : 1

Discussion

9757.	For a constant hydraulic stress on an object, the fractional change in the object's volume\[\left( \frac{\Delta V}{V} \right)\]and its bulk modulus are related as
A.	\[\frac{\Delta V}{V}\propto B\]
B.	\[\frac{\Delta V}{V}\propto \frac{1}{B}\]
C.	\[\frac{\Delta V}{V}\propto {{B}^{2}}\]
D.	\[\frac{\Delta v}{v}\propto {{B}^{-2}}\]
Answer» C. \[\frac{\Delta V}{V}\propto {{B}^{2}}\]

Discussion

9758.	The value of electric permittivity of free space is [MP PET 1996; RPET 2001]
A.	\[9\times {{10}^{9}}N{{C}^{2}}/{{m}^{2}}\]
B.	\[8.85\times {{10}^{-12}}N{{m}^{2}}/{{C}^{2}}sec\]
C.	\[8.85\times {{10}^{-12}}{{C}^{2}}/N{{m}^{2}}\]
D.	\[9\times {{10}^{9}}{{C}^{2}}/N{{m}^{2}}\]
Answer» D. \[9\times {{10}^{9}}{{C}^{2}}/N{{m}^{2}}\]

Discussion

9759.	Surface of the lake is at 2°C. Find the temperature of the bottom of the lake [Orissa JEE 2002]
A.	\[{{2}^{o}}C\]
B.	\[{{3}^{o}}C\]
C.	\[{{4}^{o}}C\]
D.	\[{{1}^{o}}C\]
Answer» D. \[{{1}^{o}}C\]

Discussion

9760.	What should be the maximum acceptance angle at the aircore interface of an optical fibre if n1 and n2 are the refractive indices of the core and the cladding, respectively [AIIMS 2005]
A.	\[{{\sin }^{-1}}({{n}_{2}}/{{n}_{1}})\]
B.	\[{{\sin }^{-1}}\sqrt{n_{1}^{2}-n_{2}^{2}}\]
C.	\[\left[ {{\tan }^{-1}}\frac{{{n}_{2}}}{{{n}_{1}}} \right]\]
D.	\[\left[ {{\tan }^{-1}}\frac{{{n}_{1}}}{{{n}_{2}}} \right]\]
Answer» C. \[\left[ {{\tan }^{-1}}\frac{{{n}_{2}}}{{{n}_{1}}} \right]\]

Discussion

9761.	Energy levels A, B, C of a certain atom corresponding to increasing values of energy i.e. \[{{E}_{A}}
A.	\[{{\lambda }_{3}}={{\lambda }_{1}}+{{\lambda }_{2}}\]
B.	\[{{\lambda }_{3}}=\frac{{{\lambda }_{1}}{{\lambda }_{2}}}{{{\lambda }_{1}}+{{\lambda }_{2}}}\]
C.	\[{{\lambda }_{1}}+{{\lambda }_{2}}+{{\lambda }_{3}}=0\]
D.	\[\lambda _{3}^{2}=\lambda _{1}^{2}+\lambda _{2}^{2}\]
Answer» C. \[{{\lambda }_{1}}+{{\lambda }_{2}}+{{\lambda }_{3}}=0\]

Discussion

9762.	Orbital acceleration of electron is [RPET 2001]
A.	\[\frac{{{n}^{2}}{{h}^{2}}}{4{{\pi }^{2}}{{m}^{2}}{{r}^{3}}}\]
B.	\[\frac{{{n}^{2}}{{h}^{2}}}{2{{n}^{2}}{{r}^{3}}}\]
C.	\[\frac{4{{n}^{2}}{{h}^{2}}}{{{\pi }^{2}}{{m}^{2}}{{r}^{3}}}\]
D.	\[\frac{4{{n}^{2}}{{h}^{2}}}{4{{\pi }^{2}}{{m}^{2}}{{r}^{3}}}\]
Answer» B. \[\frac{{{n}^{2}}{{h}^{2}}}{2{{n}^{2}}{{r}^{3}}}\]

Discussion

9763.	Assertion : Corpuscular theory fails in explaining the velocities of light in air and water. Reason : According to corpuscular theory, light should travel faster in denser medium than, in rarer medium. [AIIMS 1998]
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

9764.	If an ac main supply is given to be 220 V. What would be the average e.m.f. during a positive half cycle [MH CET 2002]
A.	198V
B.	386V
C.	256V
D.	None of these
Answer» B. 386V

Discussion

9765.	Assertion : Spring balances show correct readings even after they had been used for a long time interval. Reason : On using for long time, spring balances losses its elastic strength.
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

9766.	Two vessels of different materials are similar in size in every respect. The same quantity of ice filled in them gets melted in 20 minutes and 30 minutes. The ratio of their thermal conductivities will be [MP PMT 1989; CMEET Bihar 1995]
A.	1.5
B.	1
C.	2/3
D.	4
Answer» B. 1

Discussion

9767.	The frequency for which a \[5\,\mu F\] capacitor has a reactance of \[\frac{1}{1000}\] ohm is given by [MP PET 1997]
A.	\[\frac{100}{\pi }MHz\]
B.	\[\frac{1000}{\pi }Hz\]
C.	\[\frac{1}{1000}Hz\]
D.	1000 Hz
Answer» B. \[\frac{1000}{\pi }Hz\]

Discussion

9768.	The amount of work done in an adiabatic expansion from temperature T to \[{{T}_{1}}\] is [MP PMT 1989]
A.	\[R(T-{{T}_{1}})\]
B.	\[\frac{R}{\gamma -1}(T-{{T}_{1}})\]
C.	RT
D.	\[R(T-{{T}_{1}})(\gamma -1)\]
Answer» C. RT

Discussion

9769.	A long solenoid is formed by winding 20 turns/cm. The current necessary to produce a magnetic field of 20 millitesla inside the solenoid will be approximately \[(\frac{{{\mu }_{0}}}{4\pi }={{10}^{-7}}\,tesla-metre/ampere)\] [MP PMT 1994]
A.	8.0 A
B.	4.0 A
C.	2.0 A
D.	1.0 A
Answer» B. 4.0 A

Discussion

9770.	Assertion : The instantaneous power of an agent is measured as the dot product of instantaneous velocity and the force acting on it at that instant. Reason : The unit of instantaneous power is watt.
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

9771.	Assertion : The following circuit represents 'OR' gate Reason : For the above circuit \[Y=\bar{X}=\overline{\overline{A+B}}=A+B\]
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

9772.	Assertion : Zeroth law of thermodynamic explain the concept of energy. Reason : Energy is dependent on temperature.
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

9773.	Assertion : A bird perches on a high power line and nothing happens to the bird. Reason : The level of bird is very high from the ground.
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

9774.	The capacity of a condenser is \[4\times {{10}^{-6}}\] farad and its potential is\[100\,\,volts\]. The energy released on discharging it fully will be [AFMC 1988; AIIMS 1980, 84]
A.	\[0.02\ Joule\]
B.	\[0.04Joule\]
C.	\[0.025\,Joule\]
D.	\[0.05\,Joule\]
Answer» B. \[0.04Joule\]

Discussion

9775.	Assertion : Electrons move away from a low potential to high potential region. Reason : Because electrons has negative charge [AIIMS 1999]
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

9776.	A long solenoid has 200 turns per cm and carries a current of 2.5 amps. The magnetic field at its centre is \[({{\mu }_{0}}=4\pi \times {{10}^{-7}}\,weber/amp\text{-}m)\] [MP PET 2000]
A.	\[3.14\times {{10}^{-2}}weber/{{m}^{2}}\]
B.	\[6.28\times {{10}^{-2}}weber/{{m}^{2}}\]
C.	\[9.42\times {{10}^{-2}}weber/{{m}^{2}}\]
D.	\[12.56\times {{10}^{-2}}weber/\,{{m}^{2}}\]
Answer» C. \[9.42\times {{10}^{-2}}weber/{{m}^{2}}\]

Discussion

9777.	An inductor of inductance L and resistor of resistance R are joined in series and connected by a source of frequency \[\omega \]. Power dissipated in the circuit is [AIEEE 2002; RPET 2003]
A.	\[\frac{({{R}^{2}}+{{\omega }^{2}}{{L}^{2}})}{V}\]
B.	\[\frac{{{V}^{2}}R}{({{R}^{2}}+{{\omega }^{2}}{{L}^{2}})}\]
C.	\[\frac{V}{({{R}^{2}}+{{\omega }^{2}}{{L}^{2}})}\]
D.	\[\frac{\sqrt{{{R}^{2}}+{{\omega }^{2}}{{L}^{2}}}}{{{V}^{2}}}\]
Answer» C. \[\frac{V}{({{R}^{2}}+{{\omega }^{2}}{{L}^{2}})}\]

Discussion

9778.	Cathode rays are [RPET 2000]
A.	Positive rays
B.	Neutral rays
C.	He rays
D.	Electron waves
Answer» E.

Discussion

9779.	Assertion : When we start filling an empty bucket with water, the pitch of sound produced goes on decreasing. Reason : The frequency of man voice is usually higher than that of woman.
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» E. If assertion is false but reason is true.

Discussion

9780.	Assertion : A coin is placed on phonogram turn table. The motor is started, coin moves along the moving table. Reason : The rotating table is providing necessary centripetal force to the coin.
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» E. If assertion is false but reason is true.

Discussion

9781.	Assertion : A red object appears dark in the yellow light Reason : A red colour is scattered less [AIIMS 2004]
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

9782.	Assertion : The stars twinkle while the planets do not. Reason : The stars are much bigger in size than the planets. [AIIMS 2003]
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

9783.	Choke coil works on the principle of [MP PET/PMT 1988]
A.	Transient current
B.	Self-induction
C.	Mutual induction
D.	Wattless current
Answer» C. Mutual induction

Discussion

9784.	\[N\] identical spherical drops charged to the same potential \[V\] are combined to form a big drop. The potential of the new drop will be [MP PMT 1990, 2001; KCET 2000; Kerala PET 2002]
A.	\[V\]
B.	\[V/N\]
C.	\[V\times N\]
D.	\[V\times {{N}^{2/3}}\]
Answer» E.

Discussion

9785.	Assertion : There is no effect of rotation of earth on acceleration due to gravity at poles. Reason : Rotation of earth is about polar axis.
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

9786.	In a LCR circuit capacitance is changed from C to 2C. For the resonant frequency to remain unchanged, the inductance should be change from L to [AIEEE 2004]
A.	4L
B.	2L
C.	L/2
D.	L/4
Answer» D. L/4

Discussion

9787.	If a force of 250 N act on body, the momentum acquired is 125 kg-m/s. What is the period for which force acts on the body [CMEET Bihar 1995]
A.	0.5 sec
B.	0.2 sec
C.	0.4 sec
D.	0.25 sec
Answer» B. 0.2 sec

Discussion

9788.	Assertion : For best contrast between maxima and minima in the interference pattern of Young?s double slit experiment, the intensity of light emerging out of the two slits should be equal. Reason : The intensity of interference pattern is proportional to square of amplitude.
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

9789.	Assertion : Sterss is the internal force per unit area of a body. Reason : Rubber is less elastic than steel.
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

9790.	Assertion : The average velocity of the object over an interval of time is either smaller than or equal to the average speed of the object over the same interval. Reason : Velocity is a vector quantity and speed is a scalar quantity.
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

9791.	Assertion : Electric appliances with metallic body; e.g. heaters, presses etc, have three pin connections, whereas an electric bulb has a two pin connection. [AIIMS 1996] Reason : Three pin connections reduce heating of connecting cables.
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

9792.	Nature of meniscus for liquid of \[{{0}^{o}}\] angle of contact [RPET 2001]
A.	Plane
B.	Parabolic
C.	Semi-spherical
D.	Cylindrical
Answer» D. Cylindrical

Discussion

9793.	If there are n capacitors in parallel connected to V volt source, then the energy stored is equal to [AIEEE 2002]
A.	CV
B.	\[\frac{1}{2}nC{{V}^{2}}\]
C.	\[C{{V}^{2}}\]
D.	\[\frac{1}{2n}C{{V}^{2}}\]
Answer» C. \[C{{V}^{2}}\]

Discussion

9794.	Assertion : It is easier to spray water in which some soap is dissolved. Reason : Soap is easier to spread.
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

9795.	Two tuning forks A and B vibrating simultaneously produce 5 beats. Frequency of B is 512. It is seen that if one arm of A is filed, then the number of beats increases. Frequency of A will be [MP PMT 1991]
A.	502
B.	507
C.	517
D.	522
Answer» D. 522

Discussion

9796.	The electrochemical equivalent of a material in an electrolyte depends on [MP PET 2001]
A.	The nature of the material
B.	The current through the electrolyte
C.	The amount of charge passed through electrolyte
D.	The amount of material present in electrolyte
Answer» B. The current through the electrolyte

Discussion

9797.	In a purely resistive ac circuit, the current [Roorkee 1992]
A.	Lags behind the e.m.f. in phase
B.	Is in phase with the e.m.f.
C.	Leads the e.m.f. in phase
D.	Leads the e.m.f. in half the cycle and lags behind it in the other half
Answer» C. Leads the e.m.f. in phase

Discussion

9798.	Assertion : In Young?s double slit experiment, the fringes become indistinct if one of the slits is covered with cellophane paper. Reason : The cellophane paper decrease the wavelength of light.
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

9799.	The capacity of an air condenser is 2.0 mF. If a medium is placed between its plates. The capacity becomes 12 mF. The dielectric constant of the medium will be [Pb. PMT 2003]
A.	5
B.	4
C.	3
D.	6
Answer» E.

Discussion

9800.	Assertion : Soft and hard X-rays differ in frequency as well as velocity. Reason : The penetrating power of hard X-rays is more than the penetrating power of soft X-rays.
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

Explore topic-wise MCQs in Joint Entrance Exam - Main (JEE Main).

Forces \[{{F}_{1}}\] and \[{{F}_{2}}\] act on a point mass in two mutually perpendicular directions. The resultant force on the point mass will be [CPMT 1991]

The temperature of hot and cold end of a \[20cm\] long rod in thermal steady state are at \[{{100}^{o}}C\] and \[{{20}^{o}}C\] respectively. Temperature at the centre of the rod is [MP PMT 1996]

Two conducting spheres of radii 5 cm and 10 cm are given a charge of \[15\mu C\] each. After the two spheres are joined by a conducting wire, the charge on the smaller sphere is [AMU (Engg.) 2001]

The ionisation energy of hydrogen atom is 13.6 eV. Following Bohr's theory, the energy corresponding to a transition between the 3rd and the 4th orbit is [CBSE PMT 1992; DPMT 2000; RPMT 1999; AMU (Med.) 2001]

The ratio of the wavelengths for 2 ® 1 transition in Li++, He+ and H is [UPSEAT 2003]

For a constant hydraulic stress on an object, the fractional change in the object's volume\[\left( \frac{\Delta V}{V} \right)\]and its bulk modulus are related as

The value of electric permittivity of free space is [MP PET 1996; RPET 2001]

Surface of the lake is at 2°C. Find the temperature of the bottom of the lake [Orissa JEE 2002]

What should be the maximum acceptance angle at the aircore interface of an optical fibre if n1 and n2 are the refractive indices of the core and the cladding, respectively [AIIMS 2005]

Energy levels A, B, C of a certain atom corresponding to increasing values of energy i.e. \[{{E}_{A}}

Orbital acceleration of electron is [RPET 2001]

Assertion : Corpuscular theory fails in explaining the velocities of light in air and water. Reason : According to corpuscular theory, light should travel faster in denser medium than, in rarer medium. [AIIMS 1998]

If an ac main supply is given to be 220 V. What would be the average e.m.f. during a positive half cycle [MH CET 2002]

Assertion : Spring balances show correct readings even after they had been used for a long time interval. Reason : On using for long time, spring balances losses its elastic strength.

Two vessels of different materials are similar in size in every respect. The same quantity of ice filled in them gets melted in 20 minutes and 30 minutes. The ratio of their thermal conductivities will be [MP PMT 1989; CMEET Bihar 1995]

The frequency for which a \[5\,\mu F\] capacitor has a reactance of \[\frac{1}{1000}\] ohm is given by [MP PET 1997]

The amount of work done in an adiabatic expansion from temperature T to \[{{T}_{1}}\] is [MP PMT 1989]

A long solenoid is formed by winding 20 turns/cm. The current necessary to produce a magnetic field of 20 millitesla inside the solenoid will be approximately \[(\frac{{{\mu }_{0}}}{4\pi }={{10}^{-7}}\,tesla-metre/ampere)\] [MP PMT 1994]

Assertion : The instantaneous power of an agent is measured as the dot product of instantaneous velocity and the force acting on it at that instant. Reason : The unit of instantaneous power is watt.

Assertion : The following circuit represents 'OR' gate Reason : For the above circuit \[Y=\bar{X}=\overline{\overline{A+B}}=A+B\]

Assertion : Zeroth law of thermodynamic explain the concept of energy. Reason : Energy is dependent on temperature.

Assertion : A bird perches on a high power line and nothing happens to the bird. Reason : The level of bird is very high from the ground.

The capacity of a condenser is \[4\times {{10}^{-6}}\] farad and its potential is\[100\,\,volts\]. The energy released on discharging it fully will be [AFMC 1988; AIIMS 1980, 84]

Assertion : Electrons move away from a low potential to high potential region. Reason : Because electrons has negative charge [AIIMS 1999]

A long solenoid has 200 turns per cm and carries a current of 2.5 amps. The magnetic field at its centre is \[({{\mu }_{0}}=4\pi \times {{10}^{-7}}\,weber/amp\text{-}m)\] [MP PET 2000]

An inductor of inductance L and resistor of resistance R are joined in series and connected by a source of frequency \[\omega \]. Power dissipated in the circuit is [AIEEE 2002; RPET 2003]

Cathode rays are [RPET 2000]

Assertion : When we start filling an empty bucket with water, the pitch of sound produced goes on decreasing. Reason : The frequency of man voice is usually higher than that of woman.

Assertion : A coin is placed on phonogram turn table. The motor is started, coin moves along the moving table. Reason : The rotating table is providing necessary centripetal force to the coin.

Assertion : A red object appears dark in the yellow light Reason : A red colour is scattered less [AIIMS 2004]

Assertion : The stars twinkle while the planets do not. Reason : The stars are much bigger in size than the planets. [AIIMS 2003]

Choke coil works on the principle of [MP PET/PMT 1988]

\[N\] identical spherical drops charged to the same potential \[V\] are combined to form a big drop. The potential of the new drop will be [MP PMT 1990, 2001; KCET 2000; Kerala PET 2002]

Assertion : There is no effect of rotation of earth on acceleration due to gravity at poles. Reason : Rotation of earth is about polar axis.

In a LCR circuit capacitance is changed from C to 2C. For the resonant frequency to remain unchanged, the inductance should be change from L to [AIEEE 2004]

If a force of 250 N act on body, the momentum acquired is 125 kg-m/s. What is the period for which force acts on the body [CMEET Bihar 1995]

Assertion : For best contrast between maxima and minima in the interference pattern of Young?s double slit experiment, the intensity of light emerging out of the two slits should be equal. Reason : The intensity of interference pattern is proportional to square of amplitude.

Assertion : Sterss is the internal force per unit area of a body. Reason : Rubber is less elastic than steel.

Assertion : The average velocity of the object over an interval of time is either smaller than or equal to the average speed of the object over the same interval. Reason : Velocity is a vector quantity and speed is a scalar quantity.

Assertion : Electric appliances with metallic body; e.g. heaters, presses etc, have three pin connections, whereas an electric bulb has a two pin connection. [AIIMS 1996] Reason : Three pin connections reduce heating of connecting cables.

Nature of meniscus for liquid of \[{{0}^{o}}\] angle of contact [RPET 2001]

If there are n capacitors in parallel connected to V volt source, then the energy stored is equal to [AIEEE 2002]

Assertion : It is easier to spray water in which some soap is dissolved. Reason : Soap is easier to spread.

Two tuning forks A and B vibrating simultaneously produce 5 beats. Frequency of B is 512. It is seen that if one arm of A is filed, then the number of beats increases. Frequency of A will be [MP PMT 1991]

The electrochemical equivalent of a material in an electrolyte depends on [MP PET 2001]

In a purely resistive ac circuit, the current [Roorkee 1992]

Assertion : In Young?s double slit experiment, the fringes become indistinct if one of the slits is covered with cellophane paper. Reason : The cellophane paper decrease the wavelength of light.

The capacity of an air condenser is 2.0 mF. If a medium is placed between its plates. The capacity becomes 12 mF. The dielectric constant of the medium will be [Pb. PMT 2003]

Assertion : Soft and hard X-rays differ in frequency as well as velocity. Reason : The penetrating power of hard X-rays is more than the penetrating power of soft X-rays.