12583 + Mcqs in Physics Page 20 McqOptions

951.	In X-ray spectrum wavelength l of line \[{{K}_{\alpha }}\] depends on atomic number Z as [RPMT 1995; DCE 2002]
A.	\[\lambda \propto {{Z}^{2}}\]
B.	\[\lambda \propto {{(Z-1)}^{2}}\]
C.	\[\lambda \propto \frac{1}{(Z-1)}\]
D.	\[\lambda \propto \frac{1}{{{(Z-1)}^{2}}}\]
Answer» E.

Discussion

952.	A 0.5 cm high object is placed at 30 cm from a convex mirror whose focal length is 20 cm. Find the position and size of the image.
A.	12 cm, 0.2 cm
B.	18 cm, 0.2 cm
C.	6 cm, 0.5 cm
D.	5 cm, 0.1 cm
Answer» B. 18 cm, 0.2 cm

Discussion

953.	5 litre of benzene weighs [MNR 1996]
A.	More in summer than in winter
B.	More in winter than in summer
C.	Equal in winter and summer
D.	None of the above
Answer» C. Equal in winter and summer

Discussion

954.	A spring with spring constant k is extended from \[x=0\]to\[x={{x}_{1}}\]. The work done will be [Orissa PMT 2004]
A.	\[kx_{1}^{2}\]
B.	\[\frac{1}{2}kx_{1}^{2}\]
C.	\[2kx_{1}^{2}\]
D.	\[2k{{x}_{1}}\]
Answer» C. \[2kx_{1}^{2}\]

Discussion

955.	When the forward bias voltage of a diode is changed from \[0.6\text{ }V\] to \[0.7\text{ }V,\] the current changes from \[5\text{ }mA\] to\[15\text{ }mA\]. Then its forward bias resistance is
A.	\[0.01\,\Omega \]
B.	\[0.1\,\Omega \]
C.	\[10\,\Omega \]
D.	\[100\,\Omega \]
Answer» D. \[100\,\Omega \]

Discussion

956.	In cold countries, water pipes sometimes burst, because
A.	Pipe contracts
B.	Water expands on freezing
C.	When water freezes, pressure increases
D.	When water freezes, it takes heat from pipes
Answer» C. When water freezes, pressure increases

Discussion

957.	The potential barrier, in the depletion layer, is due to[EAMCET (Engg.) 1998; Pb. PMT 1999; Pb. PET 2001; AIIMS 2002]
A.	Ions
B.	Holes
C.	Electrons
D.	Both (b) and (c)
Answer» B. Holes

Discussion

958.	A particle of mass m is executing oscillations about the origin on the X-axis with amplitude A. Its potential energy is given as \[U(x)=\alpha {{x}^{4}}\] where a is a positive constant. The x coordinate of the particle where the potential energy is one third of the kinetic energy is
A.	\[\pm A/2\]
B.	\[\pm A/\sqrt{2}\]
C.	\[\pm A/3\]
D.	\[\pm A/\sqrt{3}\]
Answer» C. \[\pm A/3\]

Discussion

959.	A 10 micro-farad capacitor is charged to 500 V and then its plates are joined together through a resistance of 10 ohm. The heat produced in the resistance is [Orissa JEE 2003]
A.	500 J
B.	250 J
C.	125 J
D.	1.25 J
Answer» E.

Discussion

960.	At what height over the earth's pole, the free fall acceleration decreases by one percent (assume the radius of earth to be 6400 km) [KCET 1994]
A.	32 km
B.	80 km
C.	1.253 km
D.	64 km
Answer» B. 80 km

Discussion

961.	Assertion : A work done in moving a body over a closed loop is zero for every force in nature. Reason : Work done does not depend on nature of force.
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

962.	In the sonometer experiment, a tuning fork of frequency 256 Hz is in resonance with 0.4 m length of the wire when the iron load attached to free end of wire is 2 kg. If the load is immersed in water, the length of the wire in resonance would be (specific gravity of iron = 8) 4
A.	0.37 m
B.	0.43 m
C.	0.31 m
D.	0.2 m
Answer» B. 0.43 m

Discussion

963.	A 12 ohm resistor and a 0.21 henry inductor are connected in series to an ac source operating at 20 volts, 50 cycle/second. The phase angle between the current and the source voltage is [BHU 1994]
A.	30°
B.	40°
C.	80°
D.	90°
Answer» D. 90°

Discussion

964.	A 280 days old radioactive substance shows an activity of 6000 dps, 140 days later its activity becomes 3000 dps. What was its initial activity?
A.	20000 dps
B.	24000 dps
C.	12000 dps
D.	6000 dps
Answer» C. 12000 dps

Discussion

965.	Beta rays emitted by a radioactive material are
A.	Electromagnetic radiation
B.	The electrons orbiting around the nucleus
C.	Charged particles emitted by nucleus
D.	Neutral particles
Answer» D. Neutral particles

Discussion

966.	An archaeologist analyses the wood in a prehistoric structure and finds that \[{{C}^{14}}\](Half life = 5700 years) to \[{{C}^{12}}\]is only one- fourth of that found in the cells buried plants. The age of the wood is about
A.	5700 years
B.	2850 years
C.	11,400 years
D.	22,800 years
Answer» D. 22,800 years

Discussion

967.	The average life T and the decay constant \[\lambda \] of a radioactive nucleus are related as
A.	\[T\lambda =1\]
B.	\[T=\frac{0.693}{\lambda }\]
C.	\[\frac{T}{\lambda }=1\]
D.	\[{{\lambda }_{1}},\ {{\lambda }_{2}},\ {{\lambda }_{3}}\]
Answer» B. \[T=\frac{0.693}{\lambda }\]

Discussion

968.	Assertion : The ferromagnetic substance do not obey Curie?s law. Reason : At Curie point a ferromagnetic substance start behaving as a paramagnetic substance.
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

969.	Assertion : A bar magnet is dropped into a long vertical copper tube. Even taking air resistance as negligible, the magnet attains a constant terminal velocity. If the tube is heated, the terminal velocity gets increased. Reason : The terminal velocity depends on eddy current produced in bar magnet.
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

970.	To obtain electrons as majority charge carriers in a semiconductor, the impurity mixed is [MP PET 2000]
A.	Monovalent
B.	Divalent
C.	Trivalent
D.	Pentavalent
Answer» E.

Discussion

971.	The heart of man pumps 5 liters of blood through the arteries per minute at a pressure of 150 mm of mercury. If the density of mercury be \[13.6\times 1{{0}^{3}}kg/{{m}^{3}}\]and \[\operatorname{g} = 10m/{{s}^{2}}\]then the power of heart in watt is:
A.	2.35
B.	3.0
C.	1.5
D.	1.7
Answer» E.

Discussion

972.	A simple harmonic oscillator of angular frequency \[2\,rad\,{{s}^{-1}}\] is acted upon by an external force F = sin t N. If the oscillator is at rest in its equilibrium position at t = 0, its position at later times is given by:
A.	\[\sin \,t+\frac{1}{2}\cos \,2t\]
B.	\[\cos t-\frac{1}{2}\sin \,2t\]
C.	\[\sin t-\frac{1}{2}\sin \,2t\]
D.	\[\sin t+\frac{1}{2}\sin \,2t\]
Answer» D. \[\sin t+\frac{1}{2}\sin \,2t\]

Discussion

973.	The relationship between Young's modulus Y, Bulk modulus K and modulus of rigidity \[\eta \] is [MP PET 1991; MP PMT 1997]
A.	\[Y=\frac{9\eta K}{\eta +3K}\]
B.	\[\frac{9YK}{Y+3K}\]
C.	\[Y=\frac{9\eta K}{3+K}\]
D.	\[Y=\frac{3\eta K}{9\eta +K}\]
Answer» B. \[\frac{9YK}{Y+3K}\]

Discussion

974.	Which of the following is not reversible [Manipal MEE 1995; DPMT 2001]
A.	Joule effect
B.	Peltier effect
C.	Seebeck effect
D.	Thomson effect
Answer» B. Peltier effect

Discussion

975.	If mass of \[A=10\,\,kg\], coefficient of static friction = 0.2, coefficient of kinetic friction = 0.2. Then mass of B to start motion is [Orissa PMT 2004]
A.	2 kg
B.	2.2 kg
C.	4.8 kg
D.	200 gm
Answer» B. 2.2 kg

Discussion

976.	The amplification factor of a triode is 18 and its plate resistance is 8 ´ 103W. A load resistance of 104W is connected in the plate circuit. The voltage gain will be [RPMT 2002]
A.	30
B.	20
C.	10
D.	1
Answer» D. 1

Discussion

977.	Positive rays consists of [RPMT 1996, 2003]
A.	Electrons
B.	Neutrons
C.	Positive ions
D.	Electromagnetic waves
Answer» D. Electromagnetic waves

Discussion

978.	The division of energy by time is X. The dimensional formula of X is same as that of
A.	Momentum
B.	power
C.	Torque
D.	electric field
Answer» C. Torque

Discussion

979.	DIRECTION: Read the passage given below and answer the questions that follows:A brass ball of mass 100g is heated to \[100{}^\circ C\] and then dropped into 200g of turpentine in a calorimeter at \[15{}^\circ C\] The final temperature is found to be \[(\rho )\]. Take specific heat of brass as \[T=k\sqrt{\rho {{r}^{3}}/S}\] and water equivalent of calorimeter as 4g.Heat lost by the ball is approximately
A.	810 cal
B.	610 cal
C.	710 cal
D.	510 cal
Answer» D. 510 cal

Discussion

980.	At \[15{}^\circ C,\] a wheel has diameter of 30 cm and inside diameter of a steel rim is 29.9 cm. Coefficient of thermal expansion of steel is \[1.2\times {{10}^{-5}}{{/}^{o}}C\]. To what temperature, the rim must be heated so that it can slip over wheel?
A.	\[2787{}^\circ C\]
B.	\[2772{}^\circ C\]
C.	\[2529{}^\circ C\]
D.	\[2802{}^\circ C\]
Answer» E.

Discussion

981.	DIRECTION: Read the passage given below and answer the questions that follows: A brass ball of mass 100g is heated to \[100{}^\circ C\] and then dropped into 200g of turpentine in a calorimeter at \[15{}^\circ C\] The final temperature is found to be \[(\rho )\]. Take specific heat of brass as \[T=k\sqrt{\rho {{r}^{3}}/S}\] and water equivalent of calorimeter as 4g. Heat gained by turpentine and calorimeter is approximately
A.	810 cal
B.	610 cal
C.	710 cal
D.	510 cal
Answer» D. 510 cal

Discussion

982.	Assertion : The rate of change of total momentum of a many particle system is proportional to the sum of the internal forces of the system. Reason : Internal forces can change the kinetic energy but not the momentum of the system.
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

983.	In a bicycle, the radius of rear wheel is twice the radius of front wheel. It \[{{r}_{f}}\]and \[{{r}_{r}}\] are the radii and \[{{v}_{f}}\] and \[{{v}_{r}}\] are the speeds of topmost points of wheels then
A.	\[{{v}_{r}}=2{{v}_{f}}\]
B.	\[{{v}_{f}}=2{{v}_{r}}\]
C.	\[{{v}_{f}}={{v}_{r}}\]
D.	\[{{v}_{f}}=4{{v}_{r}}\]
Answer» D. \[{{v}_{f}}=4{{v}_{r}}\]

Discussion

984.	The work done in pulling up a block of wood weighing 2 kN for a length of 10m on a smooth plane inclined at an angle of \[15{}^\circ \] with the horizontal is [AFMC 1999; Pb PMT 2003]
A.	4.36 kJ
B.	5.17 Kj
C.	8.91 kJ
D.	9.82 kJ
Answer» C. 8.91 kJ

Discussion

985.	A spring with spring constant k when stretched through 1 cm, the potential energy is U. If it is stretched by 4 cm. The potential energy will be [Orissa PMT 2004]
A.	4U
B.	8U
C.	16 U
D.	2U
Answer» D. 2U

Discussion

986.	A diminished virtual image can be formed only in [MP PMT 2002]
A.	Plane mirror
B.	A concave mirror
C.	A convex mirror
D.	Concave-parabolic mirror
Answer» D. Concave-parabolic mirror

Discussion

987.	A convex mirror of focal length f forms an image which is \[\frac{1}{n}\] times the object. The distance of the object from the mirror is
A.	\[(n-1)f\]
B.	\[\left( \frac{n-1}{n} \right)f\]
C.	\[\left( \frac{n+1}{n} \right)f\]
D.	\[(n+1)f\]
Answer» B. \[\left( \frac{n-1}{n} \right)f\]

Discussion

988.	For a thermocouple, the temperature of inversion is that temperature at which thermo e.m.f. is
A.	Zero
B.	Maximum
C.	Minimum
D.	None of the above
Answer» B. Maximum

Discussion

989.	The surface tension for pure water in a capillary tube experiment is [MH CET 2002]
A.	\[\frac{\rho g}{2hr}\]
B.	\[\frac{2}{hr\rho g}\]
C.	\[\frac{r\rho g}{2h}\]
D.	\[\frac{hr\rho g}{2}\]
Answer» E.

Discussion

990.	Assertion : Bending a wire does not effect electrical resistance. Reason : Resistance of wire is proportional to resistivity of material.
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

991.	\[_{1}{{H}^{1}}{{+}_{1}}{{H}^{1}}{{+}_{1}}{{H}^{2}}\to X+{{\ }_{+1}}{{e}^{0}}+\]energy. The emitted particle is
A.	Neutron
B.	Proton
C.	\[\alpha -\]particle
D.	Neutrino
Answer» D. Neutrino

Discussion

992.	A black body is at a temperature of 2880 K. The energy of radiation emitted by this object with wavelength between 499 nm and 500 nm is \[{{U}_{1}}\] between 999 nm and 1000 nm is \[{{\operatorname{U}}_{2}}\] and between 1499 nm and 1500 nm is \[{{\operatorname{U}}_{3}}\] Wien's constant \[\operatorname{b}=2.88\times {{10}^{6}}nm-K\]. Then
A.	\[{{\operatorname{U}}_{1}}=0\]
B.	\[{{\operatorname{U}}_{2}}=0\]
C.	\[{{\operatorname{U}}_{1}}={{U}_{2}}\]
D.	\[{{\operatorname{U}}_{2}}>{{U}_{1}}\]
Answer» E.

Discussion

993.	In which of the following cases forces may not be required to keep the [AIIMS 1983]
A.	Particle going in a circle
B.	Particle going along a straight line
C.	The momentum of the particle constant
D.	Acceleration of the particle constant
Answer» D. Acceleration of the particle constant

Discussion

994.	An ideal gas is initially at \[{{P}_{1}}\], \[{{V}_{1}}\] is expanded to\[{{P}_{2}}\], \[{{V}_{2}}\] and then compressed adiabatically to the same volume f[ and pressure \[{{P}_{3}}\] If W is the net work done by the gas in complete process which of the following is true?
A.	\[W>0;{{P}_{3}}>{{P}_{1}}\]
B.	\[W<0;{{P}_{3}}>{{P}_{1}}\]
C.	\[W>0;{{P}_{3}}<{{P}_{1}}\]
D.	\[W<0;{{P}_{3}}<{{P}_{1}}\]
Answer» C. \[W>0;{{P}_{3}}<{{P}_{1}}\]

Discussion

995.	The pressure inside a tyre is 4 times that of atmosphere. If the tyre bursts suddenly at temperature 300 K, what will be the new temperature?
A.	\[300\text{ }{{\left( 4 \right)}^{772}}\]
B.	\[300\text{ }{{\left( 4 \right)}^{2/7}}\]
C.	\[300\text{ }{{\left( 2 \right)}^{772}}\]
D.	\[300{{\left( 4 \right)}^{-2/7}}\]
Answer» E.

Discussion

996.	The grid voltage of any triode valve is changed from ?1 volt to ? 3 volt and the mutual conductance is \[3\times {{10}^{-4}}\]mho. The change in plate circuit current will be [MNR 1999]
A.	0.8 mA
B.	0.6 mA
C.	0.4 mA
D.	1 mA
Answer» C. 0.4 mA

Discussion

997.	A man is carrying a block of a certain substance (of density 1000 \[kg{{m}^{-3}}\]) weighing 1 kg in his left hand and a bucket filled with water and weighing 10 kg in his right hand. He drops the block into the bucket. How much load does he carry in his right hand now [Manipal MEE 1995]
A.	9 kg
B.	10 kg
C.	11 kg
D.	12 kg
Answer» D. 12 kg

Discussion

998.	Assertion : The speed of satellite always remains constant in an orbit. Reason : The speed of a satellite depends on its path.
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

999.	Assertion : If a point charge q is placed in front of an infinite grounded conducting plane surface, the point charge will experience a force. Reason : This force is due to the induced charge on the conducting surface which is at zero potential.
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

1000.	In an adiabatic process, the state of a gas is changed from \[{{P}_{1}},{{V}_{1}},{{T}_{1}},\] to \[{{P}_{2}},{{V}_{2}},{{T}_{2}}\]. Which of the following relation is correct [Orissa JEE 2003]
A.	\[{{T}_{1}}{{V}_{1}}^{\gamma -1}={{T}_{2}}{{V}_{2}}^{\gamma -1}\]
B.	\[{{P}_{1}}{{V}_{1}}^{\gamma -1}={{P}_{2}}{{V}_{2}}^{\gamma -1}\]
C.	\[{{T}_{1}}{{P}_{1}}^{\gamma }={{T}_{2}}{{P}_{2}}^{\gamma }\]
D.	\[{{T}_{1}}{{V}_{1}}^{\gamma }={{T}_{2}}{{V}_{2}}^{\gamma }\]
Answer» B. \[{{P}_{1}}{{V}_{1}}^{\gamma -1}={{P}_{2}}{{V}_{2}}^{\gamma -1}\]

Discussion

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

In X-ray spectrum wavelength l of line \[{{K}_{\alpha }}\] depends on atomic number Z as [RPMT 1995; DCE 2002]

A 0.5 cm high object is placed at 30 cm from a convex mirror whose focal length is 20 cm. Find the position and size of the image.

5 litre of benzene weighs [MNR 1996]

A spring with spring constant k is extended from \[x=0\]to\[x={{x}_{1}}\]. The work done will be [Orissa PMT 2004]

When the forward bias voltage of a diode is changed from \[0.6\text{ }V\] to \[0.7\text{ }V,\] the current changes from \[5\text{ }mA\] to\[15\text{ }mA\]. Then its forward bias resistance is

In cold countries, water pipes sometimes burst, because

The potential barrier, in the depletion layer, is due to[EAMCET (Engg.) 1998; Pb. PMT 1999; Pb. PET 2001; AIIMS 2002]

A particle of mass m is executing oscillations about the origin on the X-axis with amplitude A. Its potential energy is given as \[U(x)=\alpha {{x}^{4}}\] where a is a positive constant. The x coordinate of the particle where the potential energy is one third of the kinetic energy is

A 10 micro-farad capacitor is charged to 500 V and then its plates are joined together through a resistance of 10 ohm. The heat produced in the resistance is [Orissa JEE 2003]

At what height over the earth's pole, the free fall acceleration decreases by one percent (assume the radius of earth to be 6400 km) [KCET 1994]

Assertion : A work done in moving a body over a closed loop is zero for every force in nature. Reason : Work done does not depend on nature of force.

In the sonometer experiment, a tuning fork of frequency 256 Hz is in resonance with 0.4 m length of the wire when the iron load attached to free end of wire is 2 kg. If the load is immersed in water, the length of the wire in resonance would be (specific gravity of iron = 8) 4

A 12 ohm resistor and a 0.21 henry inductor are connected in series to an ac source operating at 20 volts, 50 cycle/second. The phase angle between the current and the source voltage is [BHU 1994]

A 280 days old radioactive substance shows an activity of 6000 dps, 140 days later its activity becomes 3000 dps. What was its initial activity?

Beta rays emitted by a radioactive material are

An archaeologist analyses the wood in a prehistoric structure and finds that \[{{C}^{14}}\](Half life = 5700 years) to \[{{C}^{12}}\]is only one- fourth of that found in the cells buried plants. The age of the wood is about

The average life T and the decay constant \[\lambda \] of a radioactive nucleus are related as

Assertion : The ferromagnetic substance do not obey Curie?s law. Reason : At Curie point a ferromagnetic substance start behaving as a paramagnetic substance.

To obtain electrons as majority charge carriers in a semiconductor, the impurity mixed is [MP PET 2000]

The heart of man pumps 5 liters of blood through the arteries per minute at a pressure of 150 mm of mercury. If the density of mercury be \[13.6\times 1{{0}^{3}}kg/{{m}^{3}}\]and \[\operatorname{g} = 10m/{{s}^{2}}\]then the power of heart in watt is:

A simple harmonic oscillator of angular frequency \[2\,rad\,{{s}^{-1}}\] is acted upon by an external force F = sin t N. If the oscillator is at rest in its equilibrium position at t = 0, its position at later times is given by:

The relationship between Young's modulus Y, Bulk modulus K and modulus of rigidity \[\eta \] is [MP PET 1991; MP PMT 1997]

Which of the following is not reversible [Manipal MEE 1995; DPMT 2001]

If mass of \[A=10\,\,kg\], coefficient of static friction = 0.2, coefficient of kinetic friction = 0.2. Then mass of B to start motion is [Orissa PMT 2004]

The amplification factor of a triode is 18 and its plate resistance is 8 ´ 103W. A load resistance of 104W is connected in the plate circuit. The voltage gain will be [RPMT 2002]

Positive rays consists of [RPMT 1996, 2003]

The division of energy by time is X. The dimensional formula of X is same as that of

At \[15{}^\circ C,\] a wheel has diameter of 30 cm and inside diameter of a steel rim is 29.9 cm. Coefficient of thermal expansion of steel is \[1.2\times {{10}^{-5}}{{/}^{o}}C\]. To what temperature, the rim must be heated so that it can slip over wheel?

Assertion : The rate of change of total momentum of a many particle system is proportional to the sum of the internal forces of the system. Reason : Internal forces can change the kinetic energy but not the momentum of the system.

In a bicycle, the radius of rear wheel is twice the radius of front wheel. It \[{{r}_{f}}\]and \[{{r}_{r}}\] are the radii and \[{{v}_{f}}\] and \[{{v}_{r}}\] are the speeds of topmost points of wheels then

The work done in pulling up a block of wood weighing 2 kN for a length of 10m on a smooth plane inclined at an angle of \[15{}^\circ \] with the horizontal is [AFMC 1999; Pb PMT 2003]

A spring with spring constant k when stretched through 1 cm, the potential energy is U. If it is stretched by 4 cm. The potential energy will be [Orissa PMT 2004]

A diminished virtual image can be formed only in [MP PMT 2002]

A convex mirror of focal length f forms an image which is \[\frac{1}{n}\] times the object. The distance of the object from the mirror is

For a thermocouple, the temperature of inversion is that temperature at which thermo e.m.f. is

The surface tension for pure water in a capillary tube experiment is [MH CET 2002]

Assertion : Bending a wire does not effect electrical resistance. Reason : Resistance of wire is proportional to resistivity of material.

\[_{1}{{H}^{1}}{{+}_{1}}{{H}^{1}}{{+}_{1}}{{H}^{2}}\to X+{{\ }_{+1}}{{e}^{0}}+\]energy. The emitted particle is

In which of the following cases forces may not be required to keep the [AIIMS 1983]

An ideal gas is initially at \[{{P}_{1}}\], \[{{V}_{1}}\] is expanded to\[{{P}_{2}}\], \[{{V}_{2}}\] and then compressed adiabatically to the same volume f[ and pressure \[{{P}_{3}}\] If W is the net work done by the gas in complete process which of the following is true?

The pressure inside a tyre is 4 times that of atmosphere. If the tyre bursts suddenly at temperature 300 K, what will be the new temperature?

The grid voltage of any triode valve is changed from ?1 volt to ? 3 volt and the mutual conductance is \[3\times {{10}^{-4}}\]mho. The change in plate circuit current will be [MNR 1999]

A man is carrying a block of a certain substance (of density 1000 \[kg{{m}^{-3}}\]) weighing 1 kg in his left hand and a bucket filled with water and weighing 10 kg in his right hand. He drops the block into the bucket. How much load does he carry in his right hand now [Manipal MEE 1995]

Assertion : The speed of satellite always remains constant in an orbit. Reason : The speed of a satellite depends on its path.

Assertion : If a point charge q is placed in front of an infinite grounded conducting plane surface, the point charge will experience a force. Reason : This force is due to the induced charge on the conducting surface which is at zero potential.

In an adiabatic process, the state of a gas is changed from \[{{P}_{1}},{{V}_{1}},{{T}_{1}},\] to \[{{P}_{2}},{{V}_{2}},{{T}_{2}}\]. Which of the following relation is correct [Orissa JEE 2003]