12583 + Mcqs in Physics Page 193 McqOptions

9601.	\[\Delta U+\Delta W=0\] is valid for [RPMT 2000]
A.	Adiabatic process
B.	Isothermal process
C.	Isobaric process
D.	Isochoric process
Answer» B. Isothermal process

Discussion

9602.	Assertion : Charge is invariant. Reason : Charge does not depends on speed of frame of reference.
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

9603.	Assertion : The dc and ac both can be measured by a hot wire instrument. Reason : The hot wire instrument is based on the principle of magnetic effect of current.
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

9604.	At a common temperature, a block of wood and a block of metal feel equally cold or hot. The temperatures of block of wood and block of metal are [AIIMS 1999]
A.	Equal to temperature of the body
B.	Less than the temperature of the body
C.	Greater than temperature of the body
D.	Either (b) or (c)
Answer» B. Less than the temperature of the body

Discussion

9605.	Assertion : Cyclotron is a device which is used to accelerate the positive ion. Reason : Cyclotron frequency depends upon the velocity. [AIIMS 1997]
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

9606.	When a tuning fork vibrates, the waves produced in the fork are [AFMC 2001]
A.	Longitudinal
B.	Transverse
C.	Progressive
D.	Stationary
Answer» B. Transverse

Discussion

9607.	The negative Zn pole of a Daniel cell, sending a constant current through a circuit, decreases in mass by 0.13g in 30 minutes. If the electrochemical equivalent of Zn and Cu are 32.5 and 31.5 respectively, the increase in the mass of the positive Cu pole in this time is [AIEEE 2003]
A.	0.242 g
B.	0.190 g
C.	0.141 g
D.	0.126 g
Answer» E.

Discussion

9608.	The wavelength of the energy emitted when electron come from fourth orbit to second orbit in hydrogen is \[20.397\,cm\]. The wavelength of energy for the same transition in \[H{{e}^{+}}\]is [AIIMS 1997; JIPMER 2000]
A.	\[5.099\ c{{m}^{-1}}\]
B.	\[20.497\ c{{m}^{-1}}\]
C.	\[40.994\ c{{m}^{-1}}\]
D.	\[81.988\ c{{m}^{-1}}\]
Answer» B. \[20.497\ c{{m}^{-1}}\]

Discussion

9609.	Assertion : The division are equally marked on the scale of ac ammeter. Reason : Heat produced is directly proportional to the current.
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

9610.	A spherical drop of mercury having a potential of 2.5 V is obtained as a result of merging 125 droplets. The potential of constituent droplets would be [Orissa JEE 2003]
A.	1.0 V
B.	0.5 V
C.	0.2 V
D.	0.1 V
Answer» E.

Discussion

9611.	The density of a newly discovered planet is twice that of earth. The acceleration due to gravity at the surface of the planet is equal to that at the surface of the earth. If the radius of the earth is R, the radius of the planet would be [CBSE PMT 2004]
A.	\[2R\]
B.	\[4R\]
C.	\[\frac{1}{4}R\]
D.	\[\frac{1}{2}R\]
Answer» E.

Discussion

9612.	Assertion : Circuit containing capacitors should be handled cautiously even when there is no current. Reason : The capacitors are very delicate and so quickly break down.
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

9613.	Use of eddy currents is done in the following except
A.	Moving coil galvanometer
B.	Electric brakes
C.	Induction motor
D.	Dynamo
Answer» E.

Discussion

9614.	Assertion : The impurities always decrease the surface tension of a liquid. Reason : The change in surface tension of the liquid depends upon the degree of contamination of the impurity.
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

9615.	What will be the acceleration due to gravity at height h if h >> R. Where R is radius of earth and g is acceleration due to gravity on the surface of earth [RPET 2001]
A.	\[\frac{g}{{{\left( 1+\frac{h}{R} \right)}^{2}}}\]
B.	\[g\left( 1-\frac{2h}{R} \right)\]
C.	\[\frac{g}{{{\left( 1-\frac{h}{R} \right)}^{2}}}\]
D.	\[g\left( 1-\frac{h}{R} \right)\]
Answer» B. \[g\left( 1-\frac{2h}{R} \right)\]

Discussion

9616.	Latent heat of 1gm of steam is 536 cal/gm, then its value in joule/kg is [RPMT 1999]
A.	\[2.25\times {{10}^{6}}\]
B.	\[2.25\times {{10}^{3}}\]
C.	2.25
D.	None
Answer» B. \[2.25\times {{10}^{3}}\]

Discussion

9617.	A resonant ac circuit contains a capacitor of capacitance \[{{10}^{-6}}F\] and an inductor of \[{{10}^{-4}}H.\] The frequency of electrical oscillations will be
A.	\[{{10}^{5}}\,Hz\]
B.	10 Hz
C.	\[\frac{{{10}^{5}}}{2\pi }Hz\]
D.	\[\frac{10}{2\pi }Hz\]
Answer» D. \[\frac{10}{2\pi }Hz\]

Discussion

9618.	If liquid level falls in a capillary then radius of capillary will [RPET 2001]
A.	Increase
B.	Decrease
C.	Unchanged
D.	None of these
Answer» B. Decrease

Discussion

9619.	Three equal charges are placed on the three corners of a square. If the force between \[{{q}_{1}}\] and \[{{q}_{2}}\]is \[{{F}_{12}}\] and that between \[{{q}_{1}}\]and \[{{q}_{3}}\] is \[{{F}_{13}}\], the ratio of magnitudes \[\frac{{{F}_{12}}}{{{F}_{13}}}\] is [MP PET 1993]
A.	\[1/2\]
B.	2
C.	\[1/\sqrt{2}\]
D.	\[\sqrt{2}\]
Answer» C. \[1/\sqrt{2}\]

Discussion

9620.	The adiabatic Bulk modulus of a perfect gas at pressure is given by [CPMT 1982; MH CET 2001]
A.	P
B.	\[2P\]
C.	\[P/2\]
D.	\[\gamma P\]
Answer» E.

Discussion

9621.	Assertion : In Hertz experiment, the electric vector of radiation produced by the source gap is parallel to the gap. Reason : Production of sparks between the detector gap is maximum when it is placed perpendicular to the source gap.
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

9622.	The number of turns in primary and secondary coils of a transformer are 100 and 20 respectively. If an alternating potential of 200 volt is applied to the primary, the induced potential in secondary will be [RPET 1999]
A.	10 V
B.	40 V
C.	1000 V
D.	20,000 V
Answer» C. 1000 V

Discussion

9623.	The number of waves contained in unit length of the medium is called [AIIMS 1998]
A.	Elastic wave
B.	Wave number
C.	Wave pulse
D.	Electromagnetic wave
Answer» C. Wave pulse

Discussion

9624.	The process by which ac is converted into dc is known as [RPMT 1997]
A.	Purification
B.	Amplification
C.	Rectification
D.	Current amplification
Answer» D. Current amplification

Discussion

9625.	In an electron gun the control grid is given a negative potential relative to cathode in order to [NCERT 1988]
A.	Decelerate electrons
B.	Repel electrons and thus to control the number of electrons passing through it
C.	To select electrons of same velocity and to converge them along the axis
D.	To decrease the kinetic energy of electrons
Answer» C. To select electrons of same velocity and to converge them along the axis

Discussion

9626.	An electron is accelerated through a potential difference of 200 volts. If \[e/m\] for the electron be \[1.6\times {{10}^{11}}\] coulomb/kg, the velocity acquired by the electron will be [MP PET 2000]
A.	\[8\times {{10}^{6}}\,m/s\]
B.	\[8\times {{10}^{5}}\,m/s\]
C.	\[5.9\times {{10}^{6}}\,m/s\]
D.	\[5.9\times {{10}^{5}}\,m/s\]
Answer» B. \[8\times {{10}^{5}}\,m/s\]

Discussion

9627.	Assertion : Latent heat of fusion of ice is 336000 J kg?1. Reason : Latent heat refers to change of state without any change in 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» C. If assertion is true but reason is false.

Discussion

9628.	Assertion : If the temperature of a star is doubled then the rate of loss of heat from it becomes 16 times. Reason : Specific heat varies with temperature. [AIIMS 1996]
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

9629.	Assertion : Two different planets have same escape velocity. Reason : Value of escape velocity is a universal 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» E. If assertion is false but reason is true.

Discussion

9630.	Assertion : Vector product of two vectors is an axial vector Reason : If \[\vec{v}\] = instantaneous velocity, \[\vec{r}\]= radius vector and \[\vec{\omega }\] = angular velocity, then \[\vec{\omega }=\vec{v}\times \vec{r}.\]
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

9631.	For series LCR circuit, wrong statement is [RPMT 1997]
A.	Applied e.m.f. and potential difference across resistance are in same phase
B.	Applied e.m.f. and potential difference at inductor coil have phase difference of \[\pi /2\]
C.	Potential difference at capacitor and inductor have phase difference of \[\pi /2\]
D.	Potential difference across resistance and capacitor have phase difference of \[\pi /2\]
Answer» D. Potential difference across resistance and capacitor have phase difference of \[\pi /2\]

Discussion

9632.	Assertion : In photoelectric effect, on increasing the intensity of light, both the number of electrons emitted and kinetic energy of each of them get increased but photoelectric current remains unchanged. Reason : The photoelectric current depends only on 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» E. If assertion is false but reason is true.

Discussion

9633.	A choke coil is preferred to a rheostat in ac circuit as
A.	It consumes almost zero power
B.	It increases current
C.	It increases power
D.	It increases voltage
Answer» B. It increases current

Discussion

9634.	When a body is earth connected, electrons from the earth flow into the body. This means the body is?.. [KCET 2004]
A.	Unchanged
B.	Charged positively
C.	Charged negatively
D.	An insulator
Answer» C. Charged negatively

Discussion

9635.	In an ac circuit, the current is given by \[i=5\sin \,\left( 100\,t-\frac{\pi }{2} \right)\] and the ac potential is\[V=200\sin \,(100)\,volt.\] Then the power consumption is [CBSE PMT 1995; MH CET 1999; CPMT 2002]
A.	20 watts
B.	40 watts
C.	1000 watts
D.	0 watt
Answer» E.

Discussion

9636.	Assertion : The graph of total energy of a particle in SHM w.r.t., position is a straight line with zero slope. Reason : Total energy of particle in SHM remains constant throughout its motion.
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

9637.	If earth is supposed to be a sphere of radius R, if g30 is value of acceleration due to gravity at latitude of 30o and g at the equator, the value of \[g-{{g}_{{{30}^{o}}}}\] is [DCE 2005]
A.	\[\frac{1}{4}{{\omega }^{2}}R\]
B.	\[\frac{3}{4}{{\omega }^{2}}R\]
C.	\[{{\omega }^{2}}R\]
D.	\[\frac{1}{2}{{\omega }^{2}}R\]
Answer» C. \[{{\omega }^{2}}R\]

Discussion

9638.	If two metallic plates of equal thicknesses and thermal conductivities \[{{K}_{1}}\]and \[{{K}_{2}}\] are put together face to face and a common plate is constructed, then the equivalent thermal conductivity of this plate will be [MP PMT 1991]
A.	\[\frac{{{K}_{1}}{{K}_{2}}}{{{K}_{1}}+{{K}_{2}}}\]
B.	\[\frac{2{{K}_{1}}{{K}_{2}}}{{{K}_{1}}+{{K}_{2}}}\]
C.	\[\frac{{{(K_{1}^{2}+K_{2}^{2})}^{3/2}}}{{{K}_{1}}{{K}_{2}}}\]
D.	\[\frac{{{(K_{1}^{2}+K_{2}^{2})}^{3/2}}}{2{{K}_{1}}{{K}_{2}}}\]
Answer» C. \[\frac{{{(K_{1}^{2}+K_{2}^{2})}^{3/2}}}{{{K}_{1}}{{K}_{2}}}\]

Discussion

9639.	We consider a thermodynamic system. If \[\Delta U\]represents the increase in its internal energy and W the work done by the system, which of the following statements is true [CBSE PMT 1998]
A.	\[\Delta U=-W\] in an adiabatic process
B.	\[\Delta U=W\]in an isothermal process
C.	\[\Delta U=-W\]in an isothermal process
D.	\[\Delta U=W\]in an adiabatic process
Answer» B. \[\Delta U=W\]in an isothermal process

Discussion

9640.	Assertion : Distance-time graph of the motion of a body having uniformly accelerated motion is a straight line inclined to the time axis. Reason : Distance travelled by a body having uniformly accelerated motion is directly proportional to the square of the time taken.
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

9641.	A particle of mass 10 grams is executing simple harmonic motion with an amplitude of 0.5 m and periodic time of \[(\pi /5)\] seconds. The maximum value of the force acting on the particle is [MP PET 1999; MP PMT 2000]
A.	25 N
B.	5 N
C.	2.5 N
D.	0.5 N
Answer» E.

Discussion

9642.	The output voltage of a transformer connected to 220 volt line is 1100 volt at 1 amp current. Its efficiency is 100%. The current coming from the line is [Pb. PET 2003]
A.	20 A
B.	10 A
C.	11 A
D.	22 A
Answer» C. 11 A

Discussion

9643.	Assertion : On a rainy day sound travel slower than on a dry day. Reason : When moisture is present in air the density of air increases.
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

9644.	In Thomson's experiment if the value of q/m is the same for all positive ions striking the photographic plate, then the trace would be [RPMT 1986]
A.	Straight line
B.	Parabolic
C.	Circular
D.	Elliptical
Answer» C. Circular

Discussion

9645.	Assertion : Eddy currents is produced in any metallic conductor when magnetic flux is changed around it.Reason : Electric potential determines the flow of charge. [AIIMS 1995]
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

9646.	Assertion : Graph between potential energy of a spring versus the extension or compression of the spring is a straight line. Reason : Potential energy of a stretched or compressed spring, proportional to square of extension or compression.
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

9647.	If the mass of earth is 80 times of that of a planet and diameter is double that of planet and ?g? on earth is \[9.8\,m/{{s}^{2}}\], then the value of ?g? on that planet is [Pb. PMT 1999; CPMT 2000]
A.	\[4.9\,m/{{s}^{2}}\]
B.	\[0.98\,m/{{s}^{2}}\]
C.	\[0.49\,m/{{s}^{2}}\]
D.	\[49\,m/{{s}^{2}}\]
Answer» D. \[49\,m/{{s}^{2}}\]

Discussion

9648.	At atmospheric pressure, the water boils at 100°C. If pressure is reduced, it will boil at [MP PMT 1984]
A.	Higher temperature
B.	Lower temperature
C.	At the same temperature
D.	At critical temperature
Answer» C. At the same temperature

Discussion

9649.	In hydrogen atom which quantity is integral multiple of \[\frac{h}{2\pi }\] [DCE 2001]
A.	Angular momentum
B.	Angular velocity
C.	Angular acceleration
D.	Momentum
Answer» B. Angular velocity

Discussion

9650.	A capillary tube made of glass is dipped into mercury. Then [MP PET 1996]
A.	Mercury rises in the capillary tube
B.	Mercury rises and flows out of the capillary tube
C.	Mercury descends in the capillary tube
D.	Mercury neither rises nor descends in the capillary tube
Answer» D. Mercury neither rises nor descends in the capillary tube

Discussion

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

\[\Delta U+\Delta W=0\] is valid for [RPMT 2000]

Assertion : Charge is invariant. Reason : Charge does not depends on speed of frame of reference.

Assertion : The dc and ac both can be measured by a hot wire instrument. Reason : The hot wire instrument is based on the principle of magnetic effect of current.

At a common temperature, a block of wood and a block of metal feel equally cold or hot. The temperatures of block of wood and block of metal are [AIIMS 1999]

Assertion : Cyclotron is a device which is used to accelerate the positive ion. Reason : Cyclotron frequency depends upon the velocity. [AIIMS 1997]

When a tuning fork vibrates, the waves produced in the fork are [AFMC 2001]

The negative Zn pole of a Daniel cell, sending a constant current through a circuit, decreases in mass by 0.13g in 30 minutes. If the electrochemical equivalent of Zn and Cu are 32.5 and 31.5 respectively, the increase in the mass of the positive Cu pole in this time is [AIEEE 2003]

The wavelength of the energy emitted when electron come from fourth orbit to second orbit in hydrogen is \[20.397\,cm\]. The wavelength of energy for the same transition in \[H{{e}^{+}}\]is [AIIMS 1997; JIPMER 2000]

Assertion : The division are equally marked on the scale of ac ammeter. Reason : Heat produced is directly proportional to the current.

A spherical drop of mercury having a potential of 2.5 V is obtained as a result of merging 125 droplets. The potential of constituent droplets would be [Orissa JEE 2003]

The density of a newly discovered planet is twice that of earth. The acceleration due to gravity at the surface of the planet is equal to that at the surface of the earth. If the radius of the earth is R, the radius of the planet would be [CBSE PMT 2004]

Assertion : Circuit containing capacitors should be handled cautiously even when there is no current. Reason : The capacitors are very delicate and so quickly break down.

Use of eddy currents is done in the following except

Assertion : The impurities always decrease the surface tension of a liquid. Reason : The change in surface tension of the liquid depends upon the degree of contamination of the impurity.

What will be the acceleration due to gravity at height h if h >> R. Where R is radius of earth and g is acceleration due to gravity on the surface of earth [RPET 2001]

Latent heat of 1gm of steam is 536 cal/gm, then its value in joule/kg is [RPMT 1999]

A resonant ac circuit contains a capacitor of capacitance \[{{10}^{-6}}F\] and an inductor of \[{{10}^{-4}}H.\] The frequency of electrical oscillations will be

If liquid level falls in a capillary then radius of capillary will [RPET 2001]

Three equal charges are placed on the three corners of a square. If the force between \[{{q}_{1}}\] and \[{{q}_{2}}\]is \[{{F}_{12}}\] and that between \[{{q}_{1}}\]and \[{{q}_{3}}\] is \[{{F}_{13}}\], the ratio of magnitudes \[\frac{{{F}_{12}}}{{{F}_{13}}}\] is [MP PET 1993]

The adiabatic Bulk modulus of a perfect gas at pressure is given by [CPMT 1982; MH CET 2001]

Assertion : In Hertz experiment, the electric vector of radiation produced by the source gap is parallel to the gap. Reason : Production of sparks between the detector gap is maximum when it is placed perpendicular to the source gap.

The number of turns in primary and secondary coils of a transformer are 100 and 20 respectively. If an alternating potential of 200 volt is applied to the primary, the induced potential in secondary will be [RPET 1999]

The number of waves contained in unit length of the medium is called [AIIMS 1998]

The process by which ac is converted into dc is known as [RPMT 1997]

In an electron gun the control grid is given a negative potential relative to cathode in order to [NCERT 1988]

An electron is accelerated through a potential difference of 200 volts. If \[e/m\] for the electron be \[1.6\times {{10}^{11}}\] coulomb/kg, the velocity acquired by the electron will be [MP PET 2000]

Assertion : Latent heat of fusion of ice is 336000 J kg?1. Reason : Latent heat refers to change of state without any change in temperature

Assertion : If the temperature of a star is doubled then the rate of loss of heat from it becomes 16 times. Reason : Specific heat varies with temperature. [AIIMS 1996]

Assertion : Two different planets have same escape velocity. Reason : Value of escape velocity is a universal constant.

Assertion : Vector product of two vectors is an axial vector Reason : If \[\vec{v}\] = instantaneous velocity, \[\vec{r}\]= radius vector and \[\vec{\omega }\] = angular velocity, then \[\vec{\omega }=\vec{v}\times \vec{r}.\]

For series LCR circuit, wrong statement is [RPMT 1997]

Assertion : In photoelectric effect, on increasing the intensity of light, both the number of electrons emitted and kinetic energy of each of them get increased but photoelectric current remains unchanged. Reason : The photoelectric current depends only on wavelength of light.

A choke coil is preferred to a rheostat in ac circuit as

When a body is earth connected, electrons from the earth flow into the body. This means the body is?.. [KCET 2004]

In an ac circuit, the current is given by \[i=5\sin \,\left( 100\,t-\frac{\pi }{2} \right)\] and the ac potential is\[V=200\sin \,(100)\,volt.\] Then the power consumption is [CBSE PMT 1995; MH CET 1999; CPMT 2002]

Assertion : The graph of total energy of a particle in SHM w.r.t., position is a straight line with zero slope. Reason : Total energy of particle in SHM remains constant throughout its motion.

If earth is supposed to be a sphere of radius R, if g30 is value of acceleration due to gravity at latitude of 30o and g at the equator, the value of \[g-{{g}_{{{30}^{o}}}}\] is [DCE 2005]

If two metallic plates of equal thicknesses and thermal conductivities \[{{K}_{1}}\]and \[{{K}_{2}}\] are put together face to face and a common plate is constructed, then the equivalent thermal conductivity of this plate will be [MP PMT 1991]

We consider a thermodynamic system. If \[\Delta U\]represents the increase in its internal energy and W the work done by the system, which of the following statements is true [CBSE PMT 1998]

Assertion : Distance-time graph of the motion of a body having uniformly accelerated motion is a straight line inclined to the time axis. Reason : Distance travelled by a body having uniformly accelerated motion is directly proportional to the square of the time taken.

A particle of mass 10 grams is executing simple harmonic motion with an amplitude of 0.5 m and periodic time of \[(\pi /5)\] seconds. The maximum value of the force acting on the particle is [MP PET 1999; MP PMT 2000]

The output voltage of a transformer connected to 220 volt line is 1100 volt at 1 amp current. Its efficiency is 100%. The current coming from the line is [Pb. PET 2003]

Assertion : On a rainy day sound travel slower than on a dry day. Reason : When moisture is present in air the density of air increases.

In Thomson's experiment if the value of q/m is the same for all positive ions striking the photographic plate, then the trace would be [RPMT 1986]

Assertion : Eddy currents is produced in any metallic conductor when magnetic flux is changed around it.Reason : Electric potential determines the flow of charge. [AIIMS 1995]

Assertion : Graph between potential energy of a spring versus the extension or compression of the spring is a straight line. Reason : Potential energy of a stretched or compressed spring, proportional to square of extension or compression.

If the mass of earth is 80 times of that of a planet and diameter is double that of planet and ?g? on earth is \[9.8\,m/{{s}^{2}}\], then the value of ?g? on that planet is [Pb. PMT 1999; CPMT 2000]

At atmospheric pressure, the water boils at 100°C. If pressure is reduced, it will boil at [MP PMT 1984]

In hydrogen atom which quantity is integral multiple of \[\frac{h}{2\pi }\] [DCE 2001]

A capillary tube made of glass is dipped into mercury. Then [MP PET 1996]