12583 + Mcqs in Physics Page 202 McqOptions

10051.	Gauss is unit of which quantity [MP PET 2002]
A.	H
B.	B
C.	\[\varphi \]
D.	I
Answer» C. \[\varphi \]

Discussion

10052.	When the electron in the hydrogen atom jumps from 2nd orbit to 1st orbit, the wavelength of radiation emitted is l. When the electrons jump from 3rd orbit to 1st orbit, the wavelength of emitted radiation would be [MP PMT 2002]
A.	\[\frac{27}{32}\lambda \]
B.	\[\frac{32}{27}\lambda \]
C.	\[\frac{2}{3}\lambda \]
D.	\[\frac{3}{2}\lambda \]
Answer» B. \[\frac{32}{27}\lambda \]

Discussion

10053.	In adiabatic expansion [DPMT 1999]
A.	\[\Delta U=0\]
B.	\[\Delta U=\]negative
C.	\[\Delta U=\]positive
D.	\[\Delta W=\]zero
Answer» C. \[\Delta U=\]positive

Discussion

10054.	1A current flows through an infinitely long straight wire. The magnetic field produced at a point 1 metres away from it is [MP PMT 2001]
A.	\[2\times {{10}^{-3}}\,Tesla\]
B.	\[\frac{2}{10}\,Tesla\]
C.	\[2\times {{10}^{-7}}\,Tesla\]
D.	\[2\pi \times {{10}^{-6}}\,\text{Tesla}\]
Answer» D. \[2\pi \times {{10}^{-6}}\,\text{Tesla}\]

Discussion

10055.	Melting point of ice [CBSE PMT 1993]
A.	Increases with increasing pressure
B.	Decreases with increasing pressure
C.	Is independent of pressure
D.	Is proportional to pressure
Answer» C. Is independent of pressure

Discussion

10056.	Assertion : Linear momentum of a body changes even when it is moving uniformly in a circle. Reason : Force required to move a body uniformly along a straight line 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» C. If assertion is true but reason is false.

Discussion

10057.	Which state of triply ionised Baryllium \[(B{{e}^{+++}})\] has the same orbital radius as that of the ground state of hydrogen [KCET 2004]
A.	n = 4
B.	n = 3
C.	n = 2
D.	n = 1
Answer» D. n = 1

Discussion

10058.	Mechanical waves on the surface of a liquid are [SCRA 1996]
A.	Transverse
B.	Longitudinal
C.	Torsional
D.	Both transverse and longitudinal
Answer» E.

Discussion

10059.	For electron moving in nth orbit of H-atom the angular velocity is proportional to [RPET 1999]
A.	n
B.	1/n
C.	n3
D.	1/n3
Answer» E.

Discussion

10060.	Assertion : The electron in the hydrogen atom passes from energy level \[n=4\] to the \[n=1\] level. The maximum and minimum number of photon that can be emitted are six and one respectively. Reason : The photons are emitted when electron make a transition from the higher energy state to the lower energy state.
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

10061.	The temperature at which the vapour pressure of a liquid becomes equals to the external (atmospheric) pressure is its [Kerala (Engg.) 2001]
A.	Melting point
B.	Sublimation point
C.	Critical temperature
D.	Boiling point
Answer» E.

Discussion

10062.	Assertion : In case of bullet fired from gun, the ratio of kinetic energy of gun and bullet is equal to ratio of mass of bullet and gun. Reason : In firing, momentum is conserved.
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

10063.	The magnetic moment of a current (i) carrying circular coil of radius (r) and number of turns (n) varies as [AIIMS 2004]
A.	1/ r2
B.	1/ r
C.	r
D.	r2
Answer» E.

Discussion

10064.	Two bodies moving towards each other collide and move away in opposite directions. There is some rise in temperature of bodies because a part of the kinetic energy is converted into [BHU 2002]
A.	Heat energy
B.	Electrical energy
C.	Nuclear energy
D.	Mechanical energy
Answer» B. Electrical energy

Discussion

10065.	If \[{{\lambda }_{\text{max}}}\] is 6563 Å, then wave length of second line for Balmer series will be [RPMT 2000]
A.	\[\lambda =\frac{16}{3R}\]
B.	\[\lambda =\frac{36}{5R}\]
C.	\[\lambda =\frac{4}{3R}\]
D.	None of the above
Answer» B. \[\lambda =\frac{36}{5R}\]

Discussion

10066.	In a Thomson set-up for the determination of e/m, electrons accelerated by 2.5 \[kV\] enter the region of crossed electric and magnetic fields of strengths \[3.6\times {{10}^{4}}V{{m}^{-1}}\] and \[1.2\times {{10}^{-3}}T\] respectively and go through undeflected. The measured value of \[e/m\] of the electron is equal to [AMU 2002]
A.	\[1.0\times {{10}^{11}}C\text{-}k{{g}^{-1}}\]
B.	\[1.76\times {{10}^{11}}C\text{-}k{{g}^{-1}}\]
C.	\[1.80\times {{10}^{11}}C\text{-}k{{g}^{-1}}\]
D.	\[1.85\times {{10}^{11}}C\text{-}k{{g}^{-1}}\]
Answer» D. \[1.85\times {{10}^{11}}C\text{-}k{{g}^{-1}}\]

Discussion

10067.	A transformer is based on the principle of [AIIMS 1998; AFMC 2005]
A.	Mutual inductance
B.	Self inductance
C.	Ampere's law
D.	Lenz's law
Answer» B. Self inductance

Discussion

10068.	The freezing point of the liquid decreases when pressure is increased, if the liquid [DCE 1995]
A.	Expands while freezing
B.	Contracts while freezing
C.	Does not change in volume while freezing
D.	None of these
Answer» B. Contracts while freezing

Discussion

10069.	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

10070.	Assertion : A safe turn by a cyclist should neither be fast nor sharp. Reason : The bending angle from the vertical would decrease with increase in velocity.
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

10071.	According to Bohr's theory, the expressions for the kinetic and potential energy of an electron revolving in an orbit is given respectively by
A.	\[+\frac{{{e}^{2}}}{8\pi {{\varepsilon }_{0}}r}\]and \[-\frac{{{e}^{2}}}{4\pi {{\varepsilon }_{0}}r}\]
B.	\[+\frac{8\pi {{\varepsilon }_{0}}{{e}^{2}}}{r}\]and\[-\frac{4\pi {{\varepsilon }_{0}}{{e}^{2}}}{r}\]
C.	\[-\frac{{{e}^{2}}}{8\pi {{\varepsilon }_{0}}r}\]and \[-\frac{{{e}^{2}}}{4\pi {{\varepsilon }_{0}}r}\]
D.	\[+\frac{{{e}^{2}}}{8\pi {{\varepsilon }_{0}}r}\]and \[+\frac{{{e}^{2}}}{4\pi {{\varepsilon }_{0}}r}\]
Answer» B. \[+\frac{8\pi {{\varepsilon }_{0}}{{e}^{2}}}{r}\]and\[-\frac{4\pi {{\varepsilon }_{0}}{{e}^{2}}}{r}\]

Discussion

10072.	Where will it be profitable to purchase 1 kilogram sugar [RPET 1996]
A.	At poles
B.	At equator
C.	At \[45{}^\circ \] latitude
D.	At \[40{}^\circ \] latitude
Answer» C. At \[45{}^\circ \] latitude

Discussion

10073.	Two identical cylindrical vessels with their bases at same level each contains a liquid of density r. The height of the liquid in one vessel is \[{{h}_{1}}\] and that in the other vessel is \[{{h}_{2}}\]. The area of either base is A. The work done by gravity in equalizing the levels when the two vessels are connected, is [SCRA 1996]
A.	\[({{h}_{1}}-{{h}_{2}})g\rho \]
B.	\[({{h}_{1}}-{{h}_{2}})gA\rho \]
C.	\[\frac{1}{2}{{({{h}_{1}}-{{h}_{2}})}^{2}}gA\rho \]
D.	\[\frac{1}{4}{{({{h}_{1}}-{{h}_{2}})}^{2}}gA\rho \]
Answer» D. \[\frac{1}{4}{{({{h}_{1}}-{{h}_{2}})}^{2}}gA\rho \]

Discussion

10074.	If two tuning forks A and B are sounded together, they produce 4 beats per second. A is then slightly loaded with wax, they produce 2 beats when sounded again. The frequency of A is 256. The frequency of B will be [CPMT 1976; RPET 1998]
A.	250
B.	252
C.	260
D.	262
Answer» C. 260

Discussion

10075.	Assertion : An inductance and a resistance are connected in series with an ac circuit. In this circuit the current and the potential difference across the resistance lag behind potential difference across the inductance by an angle p/2. Reason : In LR circuit voltage leads the current by phase angle which depends on the value of inductance and resistance both.
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

10076.	A capacitor with air as the dielectric is charged to a potential of \[100\ volts\]. If the space between the plates is now filled with a dielectric of dielectric constant 10, the potential difference between the plates will be [MP PET 1992]
A.	1000\[volts\]
B.	100 \[volts\]
C.	10 \[volts\]
D.	Zero
Answer» D. Zero

Discussion

10077.	A tuning fork arrangement (pair) produces 4 beats/sec with one fork of frequency 288 cps. A little wax is placed on the unknown fork and it then produces 2 beats/sec. The frequency of the unknown fork is [KCET 1998; AIEEE 2002]
A.	286 cps
B.	292 cps
C.	294 cps
D.	288 cps
Answer» C. 294 cps

Discussion

10078.	The wavelength of a particle is 99 cm and that of other is 100 cm. Speed of sound is 396 m/s. The number of beats heard is [DCE 2001]
A.	4
B.	5
C.	1
D.	8
Answer» B. 5

Discussion

10079.	A tuning fork vibrates with 2 beats in 0.04 second. The frequency of the fork is [AFMC 2003]
A.	50 Hz
B.	100 Hz
C.	80 Hz
D.	None of these
Answer» B. 100 Hz

Discussion

10080.	At what temperature velocity of sound is double than that of at 0°C [RPMT 1999]
A.	819 K
B.	819°C
C.	600°C
D.	600 K
Answer» C. 600°C

Discussion

10081.	A stone is dropped in a well which is 19.6m deep. Echo sound is heard after 2.06 sec (after dropping) then the velocity of sound is [RPMT 1999]
A.	332.6 m/sec
B.	326.7 m/sec
C.	300.4 m/sec
D.	290.5 m/sec
Answer» C. 300.4 m/sec

Discussion

10082.	Assertion : For making permanent magnets, steel is preferred over soft iron. Reason : As retentivity of steel is smaller.
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

10083.	The law, governing the force between electric charges is known as [CPMT 1972; MP PMT 2004]
A.	Ampere's law
B.	Ohm's law
C.	Faraday's law
D.	Coulomb's law
Answer» E.

Discussion

10084.	A step-down transformer is used on a 1000 V line to deliver 20 A at 120 V at the secondary coil. If the efficiency of the transformer is 80% the current drawn from the line is [Kerala PET 2005]
A.	3 A
B.	30 A
C.	0.3 A
D.	2.4 A
Answer» B. 30 A

Discussion

10085.	Fan is based on [AFMC 2003]
A.	Electric Motor
B.	Electric dynamo
C.	Both
D.	None of these
Answer» B. Electric dynamo

Discussion

10086.	The mass of the earth is 81 times that of the moon and the radius of the earth is 3.5 times that of the moon. The ratio of the acceleration due to gravity at the surface of the moon to that at the surface of the earth is [MP PMT 1994]
A.	0.15
B.	0.04
C.	1
D.	6
Answer» B. 0.04

Discussion

10087.	Assertion : If a proton and an a-particle enter a uniform magnetic field perpendicularly, with the same speed, then the time period of revolution of the a-particle is double than that of proton. Reason : In a magnetic field, the time period of revolution of a charged particle is directly proportional to mass.
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

10088.	The frequency of a FM transmitter without signal input is called
A.	Lower side band frequency
B.	Upper side band frequency
C.	Resting frequency
D.	None of these
Answer» D. None of these

Discussion

10089.	Two masses of 1 gm and 4 gm are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is [AIIMS 1987; NCERT 1983; MP PMT 1993; IIT 1980; RPET 1996; CBSE PMT 1997; Orissa JEE 2003; KCET 1999; DCE 2004]
A.	4 : 1
B.	\[\sqrt{2}:1\]
C.	1 : 2
D.	1 : 16
Answer» D. 1 : 16

Discussion

10090.	The speed of a wave in a medium is 760 m/s. If 3600 waves are passing through a point, in the medium in 2 minutes, then its wavelength is [AFMC 1998; CPMT 2001]
A.	13.8 m
B.	25.3 m
C.	41.5 m
D.	57.2 m
Answer» C. 41.5 m

Discussion

10091.	Velocity of sound in air I. Increases with temperature II. Decreases with temperature III. Increase with pressure IV. Is independent of pressure V. Is independent of temperature Choose the correct answer. [Kerala (Engg.) 2001]
A.	Only I and II are true
B.	Only I and III are true
C.	Only II and III are true
D.	Only I and IV are true
Answer» E.

Discussion

10092.	The respective radii of the two spheres of a spherical condenser are \[12\ cm\] and \[9\ cm\]. The dielectric constant of the medium between them is 6. The capacity of the condenser will be [MP PET 1993]
A.	\[240pF\]
B.	\[240\mu F\]
C.	\[240F\]
D.	None of the above
Answer» B. \[240\mu F\]

Discussion

10093.	If the dielectric constant and dielectric strength be denoted by \[k\]and \[x\] respectively, then a material suitable for use as a dielectric in a capacitor must have [EAMCET 1986]
A.	High \[k\]and high \[x\]
B.	High \[k\]and low \[x\]
C.	Low \[k\]and low \[x\]
D.	Low \[k\] and high \[x\]
Answer» B. High \[k\]and low \[x\]

Discussion

10094.	In water voltameter, the electrolysis of ...... takes place [DPMT 1999]
A.	\[{{H}_{2}}O\]
B.	\[{{H}_{2}}S{{O}_{4}}\]
C.	\[{{H}_{2}}O\] and \[{{H}_{2}}S{{O}_{4}}\] both
D.	\[{{H}_{2}}\] and \[{{O}_{2}}\]
Answer» B. \[{{H}_{2}}S{{O}_{4}}\]

Discussion

10095.	In the Bohr's hydrogen atom model, the radius of the stationary orbit is directly proportional to (n = principle quantum number) [MNR 1988; SCRA 1994; CBSE PMT 1996; AIIMS 1999; DCE 2002]
A.	\[\beta \]
B.	n
C.	\[{{n}^{-2}}\]
D.	\[{{n}^{2}}\]
Answer» E.

Discussion

10096.	A sinusoidal ac current flows through a resistor of resistance R. If the peak current is\[{{I}_{p}}\], then the power dissipated is[MP PMT 1991]
A.	\[I_{p}^{2}R\cos \theta \]
B.	\[\frac{1}{2}I_{p}^{2}R\]
C.	\[\frac{4}{\pi }I_{p}^{2}R\]
D.	\[\frac{1}{\pi }I_{p}^{2}R\]
Answer» C. \[\frac{4}{\pi }I_{p}^{2}R\]

Discussion

10097.	Assertion : Photoelectric effect demonstrates the wave nature of light. Reason : The number of photoelectrons is proportional to the frequency of light.[AIIMS 2004]
A.	If both assertion and reason are true and the reason is the correct explanation of the assertion.
B.	If both assertion and reason are true but reason is not the correct explanation of the assertion.
C.	If assertion is true but reason is false.
D.	If the assertion and reason both are false.
E.	If assertion is false but reason is true.
Answer» E. If assertion is false but reason is true.

Discussion

10098.	In the process of electrolysis, the current is carried out inside the electrolyte by [AMU (Engg.) 1999]
A.	Electrons
B.	Atoms
C.	Positive and negative ions
D.	All the above
Answer» D. All the above

Discussion

10099.	The heat is flowing through two cylindrical rods of same material. The diameters of the rods are in the ratio 1 : 2 and their lengths are in the ratio 2 : 1. If the temperature difference between their ends is the same, the ratio of rate of flow of heat through them will be [NCERT 1982; CBSE PMT 1995; EAMCET 1997]
A.	1 : 1
B.	2 : 1
C.	1 : 4
D.	1 : 8
Answer» E.

Discussion

10100.	A man standing on a cliff claps his hand hears its echo after 1 sec. If sound is reflected from another mountain and velocity of sound in air is 340 m/sec. Then the distance between the man and reflection point is [RPET 2000]
A.	680 m
B.	340 m
C.	85 m
D.	170 m
Answer» E.

Discussion

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

Gauss is unit of which quantity [MP PET 2002]

When the electron in the hydrogen atom jumps from 2nd orbit to 1st orbit, the wavelength of radiation emitted is l. When the electrons jump from 3rd orbit to 1st orbit, the wavelength of emitted radiation would be [MP PMT 2002]

In adiabatic expansion [DPMT 1999]

1A current flows through an infinitely long straight wire. The magnetic field produced at a point 1 metres away from it is [MP PMT 2001]

Melting point of ice [CBSE PMT 1993]

Assertion : Linear momentum of a body changes even when it is moving uniformly in a circle. Reason : Force required to move a body uniformly along a straight line is zero.

Which state of triply ionised Baryllium \[(B{{e}^{+++}})\] has the same orbital radius as that of the ground state of hydrogen [KCET 2004]

Mechanical waves on the surface of a liquid are [SCRA 1996]

For electron moving in nth orbit of H-atom the angular velocity is proportional to [RPET 1999]

The temperature at which the vapour pressure of a liquid becomes equals to the external (atmospheric) pressure is its [Kerala (Engg.) 2001]

Assertion : In case of bullet fired from gun, the ratio of kinetic energy of gun and bullet is equal to ratio of mass of bullet and gun. Reason : In firing, momentum is conserved.

The magnetic moment of a current (i) carrying circular coil of radius (r) and number of turns (n) varies as [AIIMS 2004]

Two bodies moving towards each other collide and move away in opposite directions. There is some rise in temperature of bodies because a part of the kinetic energy is converted into [BHU 2002]

If \[{{\lambda }_{\text{max}}}\] is 6563 Å, then wave length of second line for Balmer series will be [RPMT 2000]

A transformer is based on the principle of [AIIMS 1998; AFMC 2005]

The freezing point of the liquid decreases when pressure is increased, if the liquid [DCE 1995]

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]

Assertion : A safe turn by a cyclist should neither be fast nor sharp. Reason : The bending angle from the vertical would decrease with increase in velocity.

According to Bohr's theory, the expressions for the kinetic and potential energy of an electron revolving in an orbit is given respectively by

Where will it be profitable to purchase 1 kilogram sugar [RPET 1996]

If two tuning forks A and B are sounded together, they produce 4 beats per second. A is then slightly loaded with wax, they produce 2 beats when sounded again. The frequency of A is 256. The frequency of B will be [CPMT 1976; RPET 1998]

A capacitor with air as the dielectric is charged to a potential of \[100\ volts\]. If the space between the plates is now filled with a dielectric of dielectric constant 10, the potential difference between the plates will be [MP PET 1992]

A tuning fork arrangement (pair) produces 4 beats/sec with one fork of frequency 288 cps. A little wax is placed on the unknown fork and it then produces 2 beats/sec. The frequency of the unknown fork is [KCET 1998; AIEEE 2002]

The wavelength of a particle is 99 cm and that of other is 100 cm. Speed of sound is 396 m/s. The number of beats heard is [DCE 2001]

A tuning fork vibrates with 2 beats in 0.04 second. The frequency of the fork is [AFMC 2003]

At what temperature velocity of sound is double than that of at 0°C [RPMT 1999]

A stone is dropped in a well which is 19.6m deep. Echo sound is heard after 2.06 sec (after dropping) then the velocity of sound is [RPMT 1999]

Assertion : For making permanent magnets, steel is preferred over soft iron. Reason : As retentivity of steel is smaller.

The law, governing the force between electric charges is known as [CPMT 1972; MP PMT 2004]

A step-down transformer is used on a 1000 V line to deliver 20 A at 120 V at the secondary coil. If the efficiency of the transformer is 80% the current drawn from the line is [Kerala PET 2005]

Fan is based on [AFMC 2003]

The mass of the earth is 81 times that of the moon and the radius of the earth is 3.5 times that of the moon. The ratio of the acceleration due to gravity at the surface of the moon to that at the surface of the earth is [MP PMT 1994]

The frequency of a FM transmitter without signal input is called

Two masses of 1 gm and 4 gm are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is [AIIMS 1987; NCERT 1983; MP PMT 1993; IIT 1980; RPET 1996; CBSE PMT 1997; Orissa JEE 2003; KCET 1999; DCE 2004]

The speed of a wave in a medium is 760 m/s. If 3600 waves are passing through a point, in the medium in 2 minutes, then its wavelength is [AFMC 1998; CPMT 2001]

Velocity of sound in air I. Increases with temperature II. Decreases with temperature III. Increase with pressure IV. Is independent of pressure V. Is independent of temperature Choose the correct answer. [Kerala (Engg.) 2001]

The respective radii of the two spheres of a spherical condenser are \[12\ cm\] and \[9\ cm\]. The dielectric constant of the medium between them is 6. The capacity of the condenser will be [MP PET 1993]

If the dielectric constant and dielectric strength be denoted by \[k\]and \[x\] respectively, then a material suitable for use as a dielectric in a capacitor must have [EAMCET 1986]

In water voltameter, the electrolysis of ...... takes place [DPMT 1999]

In the Bohr's hydrogen atom model, the radius of the stationary orbit is directly proportional to (n = principle quantum number) [MNR 1988; SCRA 1994; CBSE PMT 1996; AIIMS 1999; DCE 2002]

A sinusoidal ac current flows through a resistor of resistance R. If the peak current is\[{{I}_{p}}\], then the power dissipated is[MP PMT 1991]

Assertion : Photoelectric effect demonstrates the wave nature of light. Reason : The number of photoelectrons is proportional to the frequency of light.[AIIMS 2004]

In the process of electrolysis, the current is carried out inside the electrolyte by [AMU (Engg.) 1999]

A man standing on a cliff claps his hand hears its echo after 1 sec. If sound is reflected from another mountain and velocity of sound in air is 340 m/sec. Then the distance between the man and reflection point is [RPET 2000]