12583 + Mcqs in Physics Page 206 McqOptions

10251.	Assertion : Relative velocity of A w.r.t. B is greater than the velocity of either, when they are moving in opposite directions. Reason : Relative velocity of A w.r.t. \[B={{\vec{v}}_{A}}-{{\vec{v}}_{B}}\]
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

10252.	Assertion : Kinetic energy of photo electrons emitted by a photosensitive surface depends upon the intensity of incident photon. Reason : The ejection of electrons from metallic surface is possible with frequency of incident photon below the threshold frequency. [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» E. If assertion is false but reason is true.

Discussion

10253.	Television signals on earth cannot be received at distances greater than 100 km from the transmission station. The reason behind this is that [DCE 1995]
A.	The receiver antenna is unable to detect the signal at a distance greater than 100 km
B.	The TV programme consists of both audio and video signals
C.	The TV signals are less powerful than radio signals
D.	The surface of earth is curved like a sphere
Answer» E.

Discussion

10254.	In a step up transformer, if ratio of turns of primary to secondary is 1 : 10 and primary voltage is 230 V. If the load current is 2A, then the current in primary is [Orissa PMT 2005]
A.	20 A
B.	10 A
C.	2 A
D.	1 A
Answer» B. 10 A

Discussion

10255.	According to the Rutherford?s atomic model, the electrons inside the atom are [KCET (Med.) 2000]
A.	Stationary
B.	Not stationary
C.	Centralized
D.	None of these
Answer» C. Centralized

Discussion

10256.	A body of capacity \[4\,\mu \,F\] is charged to \[80\,V\] and another body of capacity \[6\,\mu \,F\] is charged to 30V. When they are connected the energy lost by \[4\,\mu \,F\] capacitor is [EAMCET 2001]
A.	7.8 mJ
B.	4.6 mJ
C.	3.2 mJ
D.	2.5 mJ
Answer» B. 4.6 mJ

Discussion

10257.	Assertion : Electric conduction in gases is possible at normal pressure. Reason : The electric conduction in gases depends only upon the potential difference between the electrodes.
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

10258.	A vessel contains 110 g of water. The heat capacity of the vessel is equal to 10 g of water. The initial temperature of water in vessel is 10°C. If 220 g of hot water at 70°C is poured in the vessel, the final temperature neglecting radiation loss, will be [UPSEAT 2000]
A.	70°C
B.	80°C
C.	60°C
D.	50°C
Answer» E.

Discussion

10259.	The ratio of electrostatic and gravitational forces acting between electron and proton separated by a distance \[5\times {{10}^{-11}}m,\] will be (Charge on electron \[=\text{ 1}.\text{6}\times \text{1}{{0}^{\text{19}}}C\], mass of electron \[=\text{ 9}.\text{1}\times \text{1}{{0}^{\text{31}}}kg\], mass of proton = \[1.6\times {{10}^{-27}}kg,\] \[\,G=6.7\times {{10}^{-11}}\,N{{m}^{2}}/k{{g}^{2}})\] [RPET 1997; Pb PMT 2003]
A.	\[\text{2}.\text{36}\times \text{1}{{0}^{\text{39}}}\]
B.	\[\text{2}.\text{36}\times \text{1}{{0}^{40}}\]
C.	\[\text{2}.\text{34}\times \text{1}{{0}^{41}}\]
D.	\[\text{2}.\text{34}\times \text{1}{{0}^{42}}\]
Answer» B. \[\text{2}.\text{36}\times \text{1}{{0}^{40}}\]

Discussion

10260.	Assertion : In Young?s experiment, the fringe width for dark fringes is different from that for white fringes. Reason : In Young?s double slit experiment the fringes are performed with a source of white light, then only black and bright fringes are observed. [AIIMS 2001]
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

10261.	A straight wire carrying a current 10 A is bent into a semicircular arc of radius 5 cm. The magnitude of magnetic field at the center is [CPMT 2000]
A.	\[1.5\times {{10}^{-5}}\,T\]
B.	\[3.14\times {{10}^{-5}}\,T\]
C.	\[6.28\times {{10}^{-5}}\,T\]
D.	\[19.6\times {{10}^{-5}}T\]
Answer» D. \[19.6\times {{10}^{-5}}T\]

Discussion

10262.	If a rubber ball is taken at the depth of 200 m in a pool, its volume decreases by 0.1%. If the density of the water is \[1\times {{10}^{3}}\,kg/{{m}^{3}}\] and \[g=10\,m/{{s}^{2}}\], then the volume elasticity in \[N/{{m}^{2}}\] will be [MP PMT 1991]
A.	\[{{10}^{8}}\]
B.	\[2\times {{10}^{8}}\]
C.	\[{{10}^{9}}\]
D.	\[2\times {{10}^{9}}\]
Answer» E.

Discussion

10263.	The energy required to remove an electron in a hydrogen atom from \[n=10\]state is [MP PMT 1993]
A.	13.6 eV
B.	1.36 eV
C.	0.136 eV
D.	0.0136 eV
Answer» D. 0.0136 eV

Discussion

10264.	A bomb of mass 9kg explodes into 2 pieces of mass 3kg and 6kg. The velocity of mass 3kg is 1.6 m/s, the K.E. of mass 6kg is [AIEEE 2002]
A.	3.84 J
B.	9.6 J
C.	1.92 J
D.	2.92 J
Answer» D. 2.92 J

Discussion

10265.	Two liquids A and B are at 32°C and 24°C. When mixed in equal masses the temperature of the mixture is found to be 28°C. Their specific heats are in the ratio of [DPMT 1996]
A.	3 : 2
B.	2 : 3
C.	1 : 1
D.	4 : 3
Answer» D. 4 : 3

Discussion

10266.	During capillary rise of a liquid in a capillary tube, the surface of contact that remains constant is of [Pb. PMT 2000]
A.	Glass and liquid
B.	Air and glass
C.	Air and liquid
D.	All of these
Answer» D. All of these

Discussion

10267.	In a pure inductive circuit or In an ac circuit containing inductance only, the current [MP PMT 1993; CPMT 1996; Kerala PET 2002]
A.	Leads the e.m.f. by 90o
B.	Lags behind the e.m.f. by 90o
C.	Sometimes leads and sometime lags behind the e.m.f.
D.	Is in phase with the e.m.f.
Answer» C. Sometimes leads and sometime lags behind the e.m.f.

Discussion

10268.	Beats are the result of [CPMT 1971; J & K CET 2002]
A.	Diffraction
B.	Destructive interference
C.	Constructive and destructive interference
D.	Superposition of two waves of nearly equal frequency
Answer» E.

Discussion

10269.	A parallel plate capacitor has a plate separation of 0.01 mm and use a dielectric (whose dielectric strength is 19 KV/mm) as an insulator. The maximum potential difference that can be applied to the terminals of the capacitor is [AMU (Engg.) 1999]
A.	190 V
B.	290 V
C.	95 V
D.	350 V
Answer» B. 290 V

Discussion

10270.	Basically, the product modulator is
A.	An amplifier
B.	A mixer
C.	A frequency separator
D.	A phase separator
Answer» C. A frequency separator

Discussion

10271.	Assertion : Electric lines of force cross each other. Reason : Electric field at a point superimpose to give one resultant electric field. [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» F.

Discussion

10272.	The only elastic modulus that applies to fluids is [BCECE 2003]
A.	Young's modulus
B.	Shear modulus
C.	Modulus of rigidity
D.	Bulk modulus
Answer» E.

Discussion

10273.	For principal quantum number \[n=3\], the possible values of orbital quantum number ?l? are [MP PET 2001; MP PMT 2001]
A.	1, 2, 3
B.	0, 1, 2, 3
C.	0, 1, 2
D.	?1, 0, +1
Answer» D. ?1, 0, +1

Discussion

10274.	The work done in an adiabatic change in a gas depends only on [CPMT 1971; MP PMT 2004]
A.	Change is pressure
B.	Change is volume
C.	Change in temperature
D.	None of the above
Answer» D. None of the above

Discussion

10275.	An ionic atom equivalent to hydrogen atom has wavelength equal to 1/4 of the wavelengths of hydrogen lines. The ion will be [RPET 1997]
A.	\[H{{e}^{+}}\]
B.	\[L{{i}^{++}}\]
C.	\[N{{e}^{9+}}\]
D.	\[N{{a}^{10+}}\]
Answer» B. \[L{{i}^{++}}\]

Discussion

10276.	Assertion : The shape of a liquid drop is spherical. Reason : The pressure inside the drop is greater than that of outside.
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

10277.	Assertion : Generally the path of a projectile from the earth is parabolic but it is elliptical for projectiles going to a very large height. Reason : The path of a projectile is independent of the gravitational force of earth.
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

10278.	The capacity and the energy stored in a parallel plate condenser with air between its plates are respectively \[{{C}_{o}}\] and \[{{W}_{o}}\]. If the air is replaced by glass (dielectric constant = 5) between the plates, the capacity of the plates and the energy stored in it will respectively be
A.	\[5{{C}_{o}},\ 5{{W}_{o}}\]
B.	\[5{{C}_{o}},\ \frac{{{W}_{0}}}{5}\]
C.	\[\frac{{{C}_{o}}}{5},\ 5{{W}_{o}}\]
D.	\[\frac{{{C}_{o}}}{5},\frac{{{W}_{o}}}{5}\]
Answer» C. \[\frac{{{C}_{o}}}{5},\ 5{{W}_{o}}\]

Discussion

10279.	Two sound waves of wavelengths 5m and 6m formed 30 beats in 3 seconds. The velocity of sound is [EAMCET 2001]
A.	300 ms?1
B.	310 ms?1
C.	320 ms?1
D.	330 ms?1
Answer» B. 310 ms?1

Discussion

10280.	A frictionless dielectric plate \[S\] is kept on a frictionless table \[T\]. A charged parallel plate capacitance \[C\] (of which the plates are frictionless) is kept near it. The plate \[S\] is between the plates. When the plate \[S\] is left between the plates [CPMT 1988]
A.	It will remain stationary on the table
B.	It is pulled by the capacitor and will pass on the other end
C.	It is pulled between the plates and will remain there
D.	All the above statements are false
Answer» D. All the above statements are false

Discussion

10281.	Assertion : In the given circuit if lamp B or C fuses then light emitted by lamp A decreases. Reason : Voltage on A decreases.
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

10282.	Assertion : paper pins are made to have pointed end. Reason : Because pointed pins have very smalll area due to which even for small applied force it exert large pressure on the surface.
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

10283.	The cathode rays have particle nature because of the fact that [CPMT 1986; MNR 1986]
A.	They can propagate in vacuum
B.	They are deflected by electric and magnetic fields
C.	They produced fluorescence
D.	They cast shadows
Answer» C. They produced fluorescence

Discussion

10284.	Assertion : A body may be accelerated even when it is moving uniformly. Reason : When direction of motion of the body is changing then body may have acceleration.
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

10285.	The ratio of the forces between two small spheres with constant charge \[(a)\] in air \[(b)\] in a medium of dielectric constant K is [MNR 1998]
A.	1 : K
B.	K : 1
C.	\[1:{{K}^{2}}\]
D.	\[{{K}^{2}}:1\]
Answer» C. \[1:{{K}^{2}}\]

Discussion

10286.	When temperature increases, the frequency of a tuning fork [AIEEE 2002]
A.	Increases
B.	Decreases
C.	Remains same
D.	Increases or decreases depending on the material
Answer» C. Remains same

Discussion

10287.	The frequency of tuning forks A and B are respectively 3% more and 2% less than the frequency of tuning fork C. When A and B are simultaneously excited, 5 beats per second are produced. Then the frequency of the tuning fork 'A' (in Hz) is [EAMCET 2001]
A.	98
B.	100
C.	103
D.	105
Answer» D. 105

Discussion

10288.	Assertion : Through the same current flows through the line wires and the filament of the bulb but heat produced in the filament is much higher then that in line wires. Reason : The filament of bulbs is made of a material of high resistance and high melting point.
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

10289.	The wavelength of light emitted from second orbit to first orbits in a hydrogen atom is [Pb. PMT 2002]
A.	\[1.215\times {{10}^{-7}}m\]
B.	\[1.215\times {{10}^{-5}}m\]
C.	\[1.215\times {{10}^{-4}}m\]
D.	\[1.215\times {{10}^{-3}}m\]
Answer» B. \[1.215\times {{10}^{-5}}m\]

Discussion

10290.	Twenty seven drops of water of the same size are equally and similarly charged. They are then united to form a bigger drop. By what factor will the electrical potential changes [MP PET 1991; MP PMT 1994; RPET 2001]
A.	9 times
B.	27 times
C.	6 times
D.	3 times
Answer» B. 27 times

Discussion

10291.	Beats are produced by two waves given by \[{{y}_{1}}=a\sin 2000\,\pi t\] and \[{{y}_{2}}=a\sin 2008\,\pi t\]. The number of beats heard per second is [CPMT 1990; DCE 1999]
A.	Zero
B.	One
C.	Four
D.	Eight
Answer» D. Eight

Discussion

10292.	An e.m.f.\[E=4\cos (1000t)\] volt is applied to an LR-circuit of inductance 3 mH and resistance 4 ohms. The amplitude of current in the circuit is [MP PMT 1997]
A.	\[\frac{4}{\sqrt{7}}A\]
B.	1.0 A
C.	\[\frac{4}{7}A\]
D.	0.8 A
Answer» E.

Discussion

10293.	Assertion : To float, a body must displace liquid whose weight is greater than the actual weight of the body. Reason : The body will experiences no net downward force, in the case of floating.
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

10294.	Assertion : For a satellite revolving very near to earth?s surface the time period of revolution is given by 1 hour 24 minutes. Reason : The period of revolution of a satellite depends only upon its height above the earth?s surface.
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

10295.	Assertion : Soft iron is used as a core of transformer. Reason : Area of hysteresis is loop for soft iron is small.
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

10296.	A steady current of 5 amps is maintained for 45 mins. During this time it deposits 4.572 gms of zinc at the cathode of a voltameter. E.C.E. of zinc is [MP PET 1994]
A.	\[3.387\times {{10}^{-4}}gm/C\]
B.	\[3.387\times {{10}^{-4}}C/gm\]
C.	\[3.384\times {{10}^{-3}}gm/C\]
D.	\[3.394\times {{10}^{-3}}C/gm\]
Answer» B. \[3.387\times {{10}^{-4}}C/gm\]

Discussion

10297.	Assertion : When a bicycle is in motion, the force of friction exerted by the ground on the two wheels is always in forward direction. Reason : The frictional force acts only when the bodies are in contact.
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

10298.	Assertion : Minimum number of non-equal vectors in a plane required to give zero resultant is three. Reason : If \[\vec{A}+\vec{B}+\vec{C}=\vec{0},\]then they must lie in one plane
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

10299.	Assertion : In a movie, ordinarily 24 frames are projected per second from one end to the other of the complete film. Reason : The image formed on retina of eye is sustained upto 1/10 second after the removal of stimulus. [AIIMS 2001]
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

10300.	Assertion : The air bubble shines in water. Reason : Air bubble in water shines due to refraction of light [AIIMS 2002]
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 : Relative velocity of A w.r.t. B is greater than the velocity of either, when they are moving in opposite directions. Reason : Relative velocity of A w.r.t. \[B={{\vec{v}}_{A}}-{{\vec{v}}_{B}}\]

Assertion : Kinetic energy of photo electrons emitted by a photosensitive surface depends upon the intensity of incident photon. Reason : The ejection of electrons from metallic surface is possible with frequency of incident photon below the threshold frequency. [AIIMS 1999]

Television signals on earth cannot be received at distances greater than 100 km from the transmission station. The reason behind this is that [DCE 1995]

In a step up transformer, if ratio of turns of primary to secondary is 1 : 10 and primary voltage is 230 V. If the load current is 2A, then the current in primary is [Orissa PMT 2005]

According to the Rutherford?s atomic model, the electrons inside the atom are [KCET (Med.) 2000]

A body of capacity \[4\,\mu \,F\] is charged to \[80\,V\] and another body of capacity \[6\,\mu \,F\] is charged to 30V. When they are connected the energy lost by \[4\,\mu \,F\] capacitor is [EAMCET 2001]

Assertion : Electric conduction in gases is possible at normal pressure. Reason : The electric conduction in gases depends only upon the potential difference between the electrodes.

A vessel contains 110 g of water. The heat capacity of the vessel is equal to 10 g of water. The initial temperature of water in vessel is 10°C. If 220 g of hot water at 70°C is poured in the vessel, the final temperature neglecting radiation loss, will be [UPSEAT 2000]

Assertion : In Young?s experiment, the fringe width for dark fringes is different from that for white fringes. Reason : In Young?s double slit experiment the fringes are performed with a source of white light, then only black and bright fringes are observed. [AIIMS 2001]

A straight wire carrying a current 10 A is bent into a semicircular arc of radius 5 cm. The magnitude of magnetic field at the center is [CPMT 2000]

If a rubber ball is taken at the depth of 200 m in a pool, its volume decreases by 0.1%. If the density of the water is \[1\times {{10}^{3}}\,kg/{{m}^{3}}\] and \[g=10\,m/{{s}^{2}}\], then the volume elasticity in \[N/{{m}^{2}}\] will be [MP PMT 1991]

The energy required to remove an electron in a hydrogen atom from \[n=10\]state is [MP PMT 1993]

A bomb of mass 9kg explodes into 2 pieces of mass 3kg and 6kg. The velocity of mass 3kg is 1.6 m/s, the K.E. of mass 6kg is [AIEEE 2002]

Two liquids A and B are at 32°C and 24°C. When mixed in equal masses the temperature of the mixture is found to be 28°C. Their specific heats are in the ratio of [DPMT 1996]

During capillary rise of a liquid in a capillary tube, the surface of contact that remains constant is of [Pb. PMT 2000]

In a pure inductive circuit or In an ac circuit containing inductance only, the current [MP PMT 1993; CPMT 1996; Kerala PET 2002]

Beats are the result of [CPMT 1971; J & K CET 2002]

A parallel plate capacitor has a plate separation of 0.01 mm and use a dielectric (whose dielectric strength is 19 KV/mm) as an insulator. The maximum potential difference that can be applied to the terminals of the capacitor is [AMU (Engg.) 1999]

Basically, the product modulator is

Assertion : Electric lines of force cross each other. Reason : Electric field at a point superimpose to give one resultant electric field. [AIIMS 1995]

The only elastic modulus that applies to fluids is [BCECE 2003]

For principal quantum number \[n=3\], the possible values of orbital quantum number ?l? are [MP PET 2001; MP PMT 2001]

The work done in an adiabatic change in a gas depends only on [CPMT 1971; MP PMT 2004]

An ionic atom equivalent to hydrogen atom has wavelength equal to 1/4 of the wavelengths of hydrogen lines. The ion will be [RPET 1997]

Assertion : The shape of a liquid drop is spherical. Reason : The pressure inside the drop is greater than that of outside.

Assertion : Generally the path of a projectile from the earth is parabolic but it is elliptical for projectiles going to a very large height. Reason : The path of a projectile is independent of the gravitational force of earth.

The capacity and the energy stored in a parallel plate condenser with air between its plates are respectively \[{{C}_{o}}\] and \[{{W}_{o}}\]. If the air is replaced by glass (dielectric constant = 5) between the plates, the capacity of the plates and the energy stored in it will respectively be

Two sound waves of wavelengths 5m and 6m formed 30 beats in 3 seconds. The velocity of sound is [EAMCET 2001]

A frictionless dielectric plate \[S\] is kept on a frictionless table \[T\]. A charged parallel plate capacitance \[C\] (of which the plates are frictionless) is kept near it. The plate \[S\] is between the plates. When the plate \[S\] is left between the plates [CPMT 1988]

Assertion : In the given circuit if lamp B or C fuses then light emitted by lamp A decreases. Reason : Voltage on A decreases.

Assertion : paper pins are made to have pointed end. Reason : Because pointed pins have very smalll area due to which even for small applied force it exert large pressure on the surface.

The cathode rays have particle nature because of the fact that [CPMT 1986; MNR 1986]

Assertion : A body may be accelerated even when it is moving uniformly. Reason : When direction of motion of the body is changing then body may have acceleration.

The ratio of the forces between two small spheres with constant charge \[(a)\] in air \[(b)\] in a medium of dielectric constant K is [MNR 1998]

When temperature increases, the frequency of a tuning fork [AIEEE 2002]

The frequency of tuning forks A and B are respectively 3% more and 2% less than the frequency of tuning fork C. When A and B are simultaneously excited, 5 beats per second are produced. Then the frequency of the tuning fork 'A' (in Hz) is [EAMCET 2001]

Assertion : Through the same current flows through the line wires and the filament of the bulb but heat produced in the filament is much higher then that in line wires. Reason : The filament of bulbs is made of a material of high resistance and high melting point.

The wavelength of light emitted from second orbit to first orbits in a hydrogen atom is [Pb. PMT 2002]

Twenty seven drops of water of the same size are equally and similarly charged. They are then united to form a bigger drop. By what factor will the electrical potential changes [MP PET 1991; MP PMT 1994; RPET 2001]

Beats are produced by two waves given by \[{{y}_{1}}=a\sin 2000\,\pi t\] and \[{{y}_{2}}=a\sin 2008\,\pi t\]. The number of beats heard per second is [CPMT 1990; DCE 1999]

An e.m.f.\[E=4\cos (1000t)\] volt is applied to an LR-circuit of inductance 3 mH and resistance 4 ohms. The amplitude of current in the circuit is [MP PMT 1997]

Assertion : To float, a body must displace liquid whose weight is greater than the actual weight of the body. Reason : The body will experiences no net downward force, in the case of floating.

Assertion : For a satellite revolving very near to earth?s surface the time period of revolution is given by 1 hour 24 minutes. Reason : The period of revolution of a satellite depends only upon its height above the earth?s surface.

Assertion : Soft iron is used as a core of transformer. Reason : Area of hysteresis is loop for soft iron is small.

A steady current of 5 amps is maintained for 45 mins. During this time it deposits 4.572 gms of zinc at the cathode of a voltameter. E.C.E. of zinc is [MP PET 1994]

Assertion : When a bicycle is in motion, the force of friction exerted by the ground on the two wheels is always in forward direction. Reason : The frictional force acts only when the bodies are in contact.

Assertion : Minimum number of non-equal vectors in a plane required to give zero resultant is three. Reason : If \[\vec{A}+\vec{B}+\vec{C}=\vec{0},\]then they must lie in one plane

Assertion : In a movie, ordinarily 24 frames are projected per second from one end to the other of the complete film. Reason : The image formed on retina of eye is sustained upto 1/10 second after the removal of stimulus. [AIIMS 2001]

Assertion : The air bubble shines in water. Reason : Air bubble in water shines due to refraction of light [AIIMS 2002]