12583 + Mcqs in Physics Page 217 McqOptions

10801.	Assertion : The focal length of lens does not change when red light is replaced by blue light. Reason : The focal length of lens does not depends on colour of light used.
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

10802.	Assertion : Free electron always keep on moving in a conductor even then no magnetic force act on them in magnetic field unless a current is passed through it. Reason : The average velocity of free electron is zero.
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

10803.	Assertion : All the materials always have the same colour, whether viewed by reflected light or through transmitted light. Reason : The colour of material does not depend on nature 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

10804.	Assertion : It is necessary to use satellites for long distance T.V. transmission. Reason : The television signals are low frequency signals.
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

10805.	Assertion : Television signals are received through sky-wave propagation. Reason : The ionosphere reflects electromagnetic waves of frequencies greater than a certain critical frequency. [AIIMS 2005]
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

10806.	Assertion : The electrical conductivity of earth?s atmosphere decrease with altitude. Reason : The high energy particles (i.e. g-rays and cosmic rays) coming from outer space and entering our earth?s atmosphere causes ionisation of the atoms of the gases present there and the pressure of gases decreases with increase in altitude.
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

10807.	The possible quantum number for 3d electron are [MP PMT 2002]
A.	\[n=3,\,l=1,\,{{m}_{l}}=+1,\,{{m}_{s}}=-\frac{1}{2}\]
B.	\[n=3,\,l=2,\,{{m}_{l}}=+2,\,{{m}_{s}}=-\frac{1}{2}\]
C.	\[n=3,\,l=1,\,{{m}_{l}}=-1,\,{{m}_{s}}=+\frac{1}{2}\]
D.	\[n=3,\,l=0,\,{{m}_{l}}=+1,\,{{m}_{s}}=-\frac{1}{2}\]
Answer» C. \[n=3,\,l=1,\,{{m}_{l}}=-1,\,{{m}_{s}}=+\frac{1}{2}\]

Discussion

10808.	The distance between two consecutive crests in a wave train produced in a string is 5 cm. If 2 complete waves pass through any point per second, the velocity of the wave is [CPMT 1990]
A.	10 cm/sec
B.	2.5 cm/sec
C.	5 cm/sec
D.	15 cm/sec
Answer» B. 2.5 cm/sec

Discussion

10809.	A tuning fork makes 256 vibrations per second in air. When the velocity of sound is 330 m/s, then wavelength of the tone emitted is [KCET 1994; AFMC 1998; MH CET 1999; CBSE PMT 1999]
A.	0.56 m
B.	0.89 m
C.	1.11 m
D.	1.29 m
Answer» E.

Discussion

10810.	Maximum useable frequency (MUF) in F-region layer is x, when the critical frequency is 60 MHz and the angle of incidence is 70°. Then x is [Himachal PMT 2003]
A.	150 MHz
B.	170 MHz
C.	175 MHz
D.	190 MHz
Answer» D. 190 MHz

Discussion

10811.	As in figure shown, if a capacitor C is charged by connecting it with resistance R, then energy is given by the battery will be [MP PMT 2003]
A.	\[\frac{1}{2}C{{V}^{2}}\]
B.	More than\[\frac{1}{2}C{{V}^{2}}\]
C.	Less than \[\frac{1}{2}C{{V}^{2}}\]
D.	Zero
Answer» C. Less than \[\frac{1}{2}C{{V}^{2}}\]

Discussion

10812.	Assertion : Hydrogen atom consists of only one electron but its emission spectrum has many lines. Reason : Only Lyman series is found in the absorption spectrum of hydrogen atom whereas in the emission spectrum, all the series are found.
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

10813.	Assertion : A double convex lens (m = 1.5) has focal length 10 cm. When the lens is immersed in water (m = 4/3) its focal length becomes 40 cm. Reason : \[\frac{1}{f}=\frac{{{\mu }_{l}}-{{\mu }_{m}}}{{{\mu }_{m}}}\,\left( \frac{1}{{{R}_{1}}}-\frac{1}{{{R}_{2}}} \right)\] [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

10814.	Assertion : The setting sun appears to be red. Reason : Scattering of light is directly proportional to the wavelength. [AIIMS 2000]
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

10815.	Assertion : Different colours travel with different speed in vacuum. Reason : Wavelength of light depends on refractive index of 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» F.

Discussion

10816.	The average power dissipated in a pure inductor of inductance L when an ac current is passing through it, is [CPMT 1974; RPMT 1997; MP PET 1999]
A.	\[\frac{1}{2}L{{I}^{2}}\]
B.	\[\frac{1}{4}L{{I}^{2}}\]
C.	\[2\,L{{i}^{2}}\]
D.	Zero (Inductance of the coil L and current I)
Answer» E.

Discussion

10817.	A body of mass 2 kg is projected vertically upwards with a velocity of \[2\,m\,{{\sec }^{-1}}\]. The K.E. of the body just before striking the ground is [EAMCET 1980]
A.	2 J
B.	1 J
C.	4 J
D.	8 J
Answer» D. 8 J

Discussion

10818.	Two identical conductors of copper and aluminium are placed in an identical electric fields. The magnitude of induced charge in the aluminium will be [AIIMS 1999]
A.	Zero
B.	Greater than in copper
C.	Equal to that in copper
D.	Less than in copper
Answer» D. Less than in copper

Discussion

10819.	The ratio of densities of nitrogen and oxygen is 14:16. The temperature at which the speed of sound in nitrogen will be same at that in oxygen at 55oC is [EAMCET (Engg.) 1999]
A.	35°C
B.	48°C
C.	65°C
D.	14°C
Answer» E.

Discussion

10820.	A wavelength 0.60 cm is produced in air and it travels at a speed of 300 ms?1. It will be an [UPSEAT 2000]
A.	Audible wave
B.	Infrasonic wave
C.	Ultrasonic wave
D.	None of the above
Answer» D. None of the above

Discussion

10821.	Assertion : The apparent weight of a body in an elevator moving with some downward acceleration is less than the actual weight of body. Reason : The part of the weight is spent in producing downward acceleration, when body is in elevator.
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

10822.	The bulk modulus of an ideal gas at constant temperature [MP PMT 2004]
A.	Is equal to its volume V
B.	Is equal to p/2
C.	Is equal to its pressure p
D.	Cannot be determined
Answer» D. Cannot be determined

Discussion

10823.	In a step-up transformer, the turn ratio is 1 : 2. A Leclanche cell (e.m.f. 1.5V) is connected across the primary. The voltage developed in the secondary would be [MP PET 1992, 99; AIIMS 2000; MP PMT 2000; RPET 2001]
A.	3.0 V
B.	0.75 V
C.	1.5 V
D.	Zero
Answer» E.

Discussion

10824.	Assertion : Mountain roads rarely go straight up the slope. Reason : Slope of mountains are large therefore more chances of vehicle to slip from roads.
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

10825.	In the figure, what is the magnetic field at the point O[MP PMT 2004]
A.	\[\frac{{{\mu }_{0}}I}{4\pi r}\]
B.	\[\frac{{{\mu }_{0}}I}{4\pi r}+\frac{{{\mu }_{0}}I}{2\pi r}\]
C.	\[\frac{{{\mu }_{0}}I}{4r}+\frac{{{\mu }_{0}}I}{4\pi r}\]
D.	\[\frac{{{\mu }_{0}}I}{4r}-\frac{{{\mu }_{0}}I}{4\pi r}\]
Answer» D. \[\frac{{{\mu }_{0}}I}{4r}-\frac{{{\mu }_{0}}I}{4\pi r}\]

Discussion

10826.	The energy of electron in first excited state of H-atom is \[-\ 3.4\ eV\] its kinetic energy is [RPET 1999; CBSE PMT 2005]
A.	? 3.4 eV
B.	+ 3.4 eV
C.	? 6.8 eV
D.	6.8 eV
Answer» C. ? 6.8 eV

Discussion

10827.	There are two metallic spheres of same radii but one is solid and the other is hollow, then [KCET 1994; BHU 1999]
A.	Solid sphere can be given more charge
B.	Hollow sphere can be given more charge
C.	They can be charged equally (maximum)
D.	None of the above
Answer» D. None of the above

Discussion

10828.	If a coil made of conducting wires is rotated between poles pieces of the permanent magnet. The motion will generate a current and this device is called [CPMT 2005]
A.	An electric motor
B.	An electric generator
C.	An electromagnet
D.	All of above
Answer» C. An electromagnet

Discussion

10829.	The Rutherford a-particle experiment shows that most of the a-particles pass through almost unscattered while some are scattered through large angles. What information does it give about the structure of the atom [AFMC 1997]
A.	Atom is hollow
B.	The whole mass of the atom is concentrated in a small centre called nucleus
C.	Nucleus is positively charged
D.	All the above
Answer» E.

Discussion

10830.	The voltage of domestic ac is 220 volt. What does this represent [MP PMT 1996]
A.	Mean voltage
B.	Peak voltage
C.	Root mean voltage
D.	Root mean square voltage
Answer» E.

Discussion

10831.	By inserting a capillary tube upto a depth l in water, the water rises to a height h. If the lower end of the capillary is closed inside water and the capillary is taken out and closed end opened, to what height the water will remain in the tube [RPET 1996; DPMT 2000]
A.	Zero
B.	\[l+h\]
C.	2h
D.	h
Answer» E.

Discussion

10832.	A stationary particle explodes into two particles of a masses m1 and m2 which move in opposite directions with velocities \[{{v}_{1}}\] and \[{{v}_{2}}.\] The ratio of their kinetic energies \[{{E}_{1}}/{{E}_{2}}\]is [CBSE PMT 2003]
A.	\[{{m}_{1}}/{{m}_{2}}\]
B.	1
C.	\[{{m}_{1}}{{v}_{2}}/{{m}_{2}}{{v}_{1}}\]
D.	\[{{m}_{2}}/{{m}_{1}}\]
Answer» E.

Discussion

10833.	Assertion : Consider motion for a mass spring system under gravity, motion of M is not a simple harmonic motion unless Mg is negligibly small. Reason : For simple harmonic motion acceleration must be proportional to displacement and is directed towards the mean position [SCRA 1994]
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

10834.	Assertion : In simple harmonic motion, the velocity is maximum when acceleration is minimum Reason : Displacement and velocity of S.H.M. differ is phase by \[\pi /2\] [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» C. If assertion is true but reason is false.

Discussion

10835.	Two vectors \[\vec{A}\,\text{ and }\vec{B}\] are such that \[\vec{A}+\vec{B}=\vec{A}-\vec{B}\]. Then [AMU (Med.) 2000]
A.	\[\vec{A}\,.\,\vec{B}=0\]
B.	\[\vec{A}\times \vec{B}=0\]
C.	\[\vec{A}=0\]
D.	\[\overrightarrow{B}=0\]
Answer» E.

Discussion

10836.	The value of g on the earth's surface is \[980\,cm/{{\sec }^{2}}\]. Its value at a height of 64 km from the earth's surface is [MP PMT 1995]
A.	\[960.40\,cm/{{\sec }^{2}}\]
B.	\[984.90\,cm/{{\sec }^{2}}\]
C.	\[982.45\,cm/{{\sec }^{2}}\]
D.	\[977.55\,cm/{{\sec }^{2}}\]
Answer» B. \[984.90\,cm/{{\sec }^{2}}\]

Discussion

10837.	Assertion : When two boats sails parallel in the same direction and close to each other, they are pulled towards each other. Reason : The viscous drag on a spherical body moving with speed v is proportional to v.
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

10838.	A parallel plate capacitor has circular plates of \[0.08m\] radius and \[1.0\times {{10}^{-3}}m\] separation. If a P.D. of \[100\ volt\]is applied, the charge will be [ISM Dhanbad 1994]
A.	\[1.8\times {{10}^{-10}}C\]
B.	\[\text{1}\text{.8}\times \text{1}{{\text{0}}^{-\text{8}}}C\]
C.	\[\text{1}\text{.8}\times \text{1}{{\text{0}}^{-\text{20}}}C\]
D.	None of these
Answer» C. \[\text{1}\text{.8}\times \text{1}{{\text{0}}^{-\text{20}}}C\]

Discussion

10839.	Assertion : Current is passed through a metallic wire, heating it red. When cold water is poured on half of its portion, then rest of the half portion become more hot. Reason : Resistances decreases due to decrease in temperature and so current through wire 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» B. If both assertion and reason are true but reason is not the correct explanation of the assertion.

Discussion

10840.	Assertion : When two coils are wound on each other, the mutual induction between the coils is maximum. Reason : Mutual induction does not depend on the orientation of the coils.
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

10841.	When we touch the terminals of a high voltage capacitor, even after a high voltage has been cut off, then the capacitor has a tendency to [AFMC 2000]
A.	Restore energy
B.	Discharge energy
C.	Affect dangerously
D.	Both B and C
Answer» E.

Discussion

10842.	An iron ball and a wooden ball of the same radius are released from a height ?h? in vacuum. The time taken by both of them to reach the ground is [NCERT 1975; AFMC 1998]
A.	Unequal
B.	Exactly equal
C.	Roughly equal
D.	Zero
Answer» C. Roughly equal

Discussion

10843.	In the above figure D and E respectively represent[CPMT 1986, 88]
A.	Absorption line of Balmer series and the ionization potential of hydrogen
B.	Absorption line of Balmer series and the wavelength lesser than lowest of the Lyman series
C.	Spectral line of Balmer series and the maximum wavelength of Lyman series
D.	Spectral line of Lyman series and the absorption of greater wavelength of limiting value of Paschen series
Answer» B. Absorption line of Balmer series and the wavelength lesser than lowest of the Lyman series

Discussion

10844.	When the pressure on water is increased the boiling temperature of water as compared to 100°C will be [RPET 1999]
A.	Lower
B.	The same
C.	Higher
D.	On the critical temperature
Answer» D. On the critical temperature

Discussion

10845.	If mass energy equivalence is taken into account, when water is cooled to form ice, the mass of water should [AIEEE 2002]
A.	Increase
B.	Remain unchanged
C.	Decrease
D.	First increase then decrease
Answer» C. Decrease

Discussion

10846.	A body of mass 0.25 kg is projected with muzzle velocity \[100\,m{{s}^{-1}}\] from a tank of mass 100 kg. What is the recoil velocity of the tank [AFMC 1996]
A.	\[5\,m{{s}^{-1}}\]
B.	\[25\,m{{s}^{-1}}\]
C.	\[0.5\,m{{s}^{-1}}\]
D.	\[0.25\,m{{s}^{-1}}\]
Answer» E.

Discussion

10847.	A particle of mass m moving with velocity \[{{V}_{0}}\]strikes a simple pendulum of mass \[m\]and sticks to it. The maximum height attained by the pendulum will be [RPET 2002]
A.	\[h=\frac{V_{0}^{2}}{8g}\]
B.	\[\sqrt{{{V}_{0}}g}\]
C.	\[2\sqrt{\frac{{{V}_{0}}}{g}}\]
D.	\[\frac{V_{0}^{2}}{4g}\]
Answer» B. \[\sqrt{{{V}_{0}}g}\]

Discussion

10848.	On connecting a battery to the two corners of a diagonal of a square conductor frame of side \[a\] the magnitude of the magnetic field at the centre will be [MP PET 2002]
A.	Zero
B.	\[\frac{{{\mu }_{o}}}{\pi a}\]
C.	\[\frac{2{{\mu }_{o}}}{\pi a}\]
D.	\[\frac{4{{\mu }_{o}}i}{\pi a}\]
Answer» B. \[\frac{{{\mu }_{o}}}{\pi a}\]

Discussion

10849.	Assertion : The frequency of a second pendulum in an elevator moving up with an acceleration half the acceleration due to gravity is 0.612 s?1. Reason : The frequency of a second pendulum does not depend upon acceleration due to gravity.
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

10850.	Assertion : The percentage change in time period is 1.5%, if the length of simple pendulum increases by 3%. Reason : Time period is directly proportional to length of pendulum.
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

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

Assertion : The focal length of lens does not change when red light is replaced by blue light. Reason : The focal length of lens does not depends on colour of light used.

Assertion : Free electron always keep on moving in a conductor even then no magnetic force act on them in magnetic field unless a current is passed through it. Reason : The average velocity of free electron is zero.

Assertion : All the materials always have the same colour, whether viewed by reflected light or through transmitted light. Reason : The colour of material does not depend on nature of light.

Assertion : It is necessary to use satellites for long distance T.V. transmission. Reason : The television signals are low frequency signals.

Assertion : Television signals are received through sky-wave propagation. Reason : The ionosphere reflects electromagnetic waves of frequencies greater than a certain critical frequency. [AIIMS 2005]

The possible quantum number for 3d electron are [MP PMT 2002]

The distance between two consecutive crests in a wave train produced in a string is 5 cm. If 2 complete waves pass through any point per second, the velocity of the wave is [CPMT 1990]

A tuning fork makes 256 vibrations per second in air. When the velocity of sound is 330 m/s, then wavelength of the tone emitted is [KCET 1994; AFMC 1998; MH CET 1999; CBSE PMT 1999]

Maximum useable frequency (MUF) in F-region layer is x, when the critical frequency is 60 MHz and the angle of incidence is 70°. Then x is [Himachal PMT 2003]

As in figure shown, if a capacitor C is charged by connecting it with resistance R, then energy is given by the battery will be [MP PMT 2003]

Assertion : Hydrogen atom consists of only one electron but its emission spectrum has many lines. Reason : Only Lyman series is found in the absorption spectrum of hydrogen atom whereas in the emission spectrum, all the series are found.

Assertion : A double convex lens (m = 1.5) has focal length 10 cm. When the lens is immersed in water (m = 4/3) its focal length becomes 40 cm. Reason : \[\frac{1}{f}=\frac{{{\mu }_{l}}-{{\mu }_{m}}}{{{\mu }_{m}}}\,\left( \frac{1}{{{R}_{1}}}-\frac{1}{{{R}_{2}}} \right)\] [AIIMS 1999]

Assertion : The setting sun appears to be red. Reason : Scattering of light is directly proportional to the wavelength. [AIIMS 2000]

Assertion : Different colours travel with different speed in vacuum. Reason : Wavelength of light depends on refractive index of medium. [AIIMS 1998]

The average power dissipated in a pure inductor of inductance L when an ac current is passing through it, is [CPMT 1974; RPMT 1997; MP PET 1999]

A body of mass 2 kg is projected vertically upwards with a velocity of \[2\,m\,{{\sec }^{-1}}\]. The K.E. of the body just before striking the ground is [EAMCET 1980]

Two identical conductors of copper and aluminium are placed in an identical electric fields. The magnitude of induced charge in the aluminium will be [AIIMS 1999]

The ratio of densities of nitrogen and oxygen is 14:16. The temperature at which the speed of sound in nitrogen will be same at that in oxygen at 55oC is [EAMCET (Engg.) 1999]

A wavelength 0.60 cm is produced in air and it travels at a speed of 300 ms?1. It will be an [UPSEAT 2000]

Assertion : The apparent weight of a body in an elevator moving with some downward acceleration is less than the actual weight of body. Reason : The part of the weight is spent in producing downward acceleration, when body is in elevator.

The bulk modulus of an ideal gas at constant temperature [MP PMT 2004]

In a step-up transformer, the turn ratio is 1 : 2. A Leclanche cell (e.m.f. 1.5V) is connected across the primary. The voltage developed in the secondary would be [MP PET 1992, 99; AIIMS 2000; MP PMT 2000; RPET 2001]

Assertion : Mountain roads rarely go straight up the slope. Reason : Slope of mountains are large therefore more chances of vehicle to slip from roads.

In the figure, what is the magnetic field at the point O[MP PMT 2004]

The energy of electron in first excited state of H-atom is \[-\ 3.4\ eV\] its kinetic energy is [RPET 1999; CBSE PMT 2005]

There are two metallic spheres of same radii but one is solid and the other is hollow, then [KCET 1994; BHU 1999]

If a coil made of conducting wires is rotated between poles pieces of the permanent magnet. The motion will generate a current and this device is called [CPMT 2005]

The Rutherford a-particle experiment shows that most of the a-particles pass through almost unscattered while some are scattered through large angles. What information does it give about the structure of the atom [AFMC 1997]

The voltage of domestic ac is 220 volt. What does this represent [MP PMT 1996]

By inserting a capillary tube upto a depth l in water, the water rises to a height h. If the lower end of the capillary is closed inside water and the capillary is taken out and closed end opened, to what height the water will remain in the tube [RPET 1996; DPMT 2000]

A stationary particle explodes into two particles of a masses m1 and m2 which move in opposite directions with velocities \[{{v}_{1}}\] and \[{{v}_{2}}.\] The ratio of their kinetic energies \[{{E}_{1}}/{{E}_{2}}\]is [CBSE PMT 2003]

Assertion : Consider motion for a mass spring system under gravity, motion of M is not a simple harmonic motion unless Mg is negligibly small. Reason : For simple harmonic motion acceleration must be proportional to displacement and is directed towards the mean position [SCRA 1994]

Assertion : In simple harmonic motion, the velocity is maximum when acceleration is minimum Reason : Displacement and velocity of S.H.M. differ is phase by \[\pi /2\] [AIIMS 1999]

Two vectors \[\vec{A}\,\text{ and }\vec{B}\] are such that \[\vec{A}+\vec{B}=\vec{A}-\vec{B}\]. Then [AMU (Med.) 2000]

The value of g on the earth's surface is \[980\,cm/{{\sec }^{2}}\]. Its value at a height of 64 km from the earth's surface is [MP PMT 1995]

Assertion : When two boats sails parallel in the same direction and close to each other, they are pulled towards each other. Reason : The viscous drag on a spherical body moving with speed v is proportional to v.

A parallel plate capacitor has circular plates of \[0.08m\] radius and \[1.0\times {{10}^{-3}}m\] separation. If a P.D. of \[100\ volt\]is applied, the charge will be [ISM Dhanbad 1994]

Assertion : Current is passed through a metallic wire, heating it red. When cold water is poured on half of its portion, then rest of the half portion become more hot. Reason : Resistances decreases due to decrease in temperature and so current through wire increases.

Assertion : When two coils are wound on each other, the mutual induction between the coils is maximum. Reason : Mutual induction does not depend on the orientation of the coils.

When we touch the terminals of a high voltage capacitor, even after a high voltage has been cut off, then the capacitor has a tendency to [AFMC 2000]

An iron ball and a wooden ball of the same radius are released from a height ?h? in vacuum. The time taken by both of them to reach the ground is [NCERT 1975; AFMC 1998]

In the above figure D and E respectively represent[CPMT 1986, 88]

When the pressure on water is increased the boiling temperature of water as compared to 100°C will be [RPET 1999]

If mass energy equivalence is taken into account, when water is cooled to form ice, the mass of water should [AIEEE 2002]

A body of mass 0.25 kg is projected with muzzle velocity \[100\,m{{s}^{-1}}\] from a tank of mass 100 kg. What is the recoil velocity of the tank [AFMC 1996]

A particle of mass m moving with velocity \[{{V}_{0}}\]strikes a simple pendulum of mass \[m\]and sticks to it. The maximum height attained by the pendulum will be [RPET 2002]

On connecting a battery to the two corners of a diagonal of a square conductor frame of side \[a\] the magnitude of the magnetic field at the centre will be [MP PET 2002]

Assertion : The frequency of a second pendulum in an elevator moving up with an acceleration half the acceleration due to gravity is 0.612 s?1. Reason : The frequency of a second pendulum does not depend upon acceleration due to gravity.

Assertion : The percentage change in time period is 1.5%, if the length of simple pendulum increases by 3%. Reason : Time period is directly proportional to length of pendulum.