50278 + Interview Questions in Physics Page 233 InterviewSolution

11601.	Two identical sound waves S1 and S2 reach a point P in phase. The resultant loudness at point is √n dB higher than the loudness of S1. Then, the value of n is [Take log102=0.3]
Answer» Two identical sound waves $S_{1}$ and $S_{2}$ reach a point $P$ in phase. The resultant loudness at point is $\sqrt{n} dB$ higher than the loudness of $S_{1}$ . Then, the value of $n$ is [Take ${log}_{10} 2 = 0.3$ ]

Discussion

11602.	A small block of mass m is kept on a bigger block of mass M which is attached to a vertical spring of spring constant k as shown in the figure. The system oscillates vertically. (a) Find the resultant force on the smaller block when it is displaced through a distance x above its equilibrium position. (b) Find the normal force on the smaller block at this position. When is this force smallest in magnitude ? (c) What can be the maximum amplitude with which the two blocks may oscillate together ?
Answer» A small block of mass m is kept on a bigger block of mass M which is attached to a vertical spring of spring constant k as shown in the figure. The system oscillates vertically. (a) Find the resultant force on the smaller block when it is displaced through a distance x above its equilibrium position. (b) Find the normal force on the smaller block at this position. When is this force smallest in magnitude ? (c) What can be the maximum amplitude with which the two blocks may oscillate together ?

11602.

A small block of mass m is kept on a bigger block of mass M which is attached to a vertical spring of spring constant k as shown in the figure. The system oscillates vertically. (a) Find the resultant force on the smaller block when it is displaced through a distance x above its equilibrium position. (b) Find the normal force on the smaller block at this position. When is this force smallest in magnitude ? (c) What can be the maximum amplitude with which the two blocks may oscillate together ?

Answer»

A small block of mass m is kept on a bigger block of mass M which is attached to a vertical spring of spring constant k as shown in the figure. The system oscillates vertically. (a) Find the resultant force on the smaller block when it is displaced through a distance x above its equilibrium position. (b) Find the normal force on the smaller block at this position. When is this force smallest in magnitude ? (c) What can be the maximum amplitude with which the two blocks may oscillate together ?

Discussion

11603.	If the vectors →a and →b are not perpendicular and →c and →d are two vectors satisfying →b×→c=→b×→d and →a⋅→d=0⋅ Then the vector →d is equal to(Consider all vectors are non-zero.)
Answer» If the vectors $\to a$ and $\to b$ are not perpendicular and $\to c$ and $\to d$ are two vectors satisfying $\to b \times \to c = \to b \times \to d$ and $\to a \cdot \to d = 0 \cdot$ Then the vector $\to d$ is equal to (Consider all vectors are non-zero.)

Discussion

11604.	what is mean by velocity and accelaration and magnitude
Answer» what is mean by velocity and accelaration and magnitude

Discussion

11605.	How range is 4 times the time in projectile?
Answer» How range is 4 times the time in projectile?

Discussion

11606.	A ray of light is incident on a plane mirror along a { vector ^ i+^ j . The normal at incidence point is { along ^ i+^ k\cdot The unit vector along the reflected ray is
Answer» A ray of light is incident on a plane mirror along a { vector ^ i+^ j . The normal at incidence point is { along ^ i+^ k\cdot The unit vector along the reflected ray is

Discussion

11607.	A large tank is filled with water to a height H. A small hole is made at the base of the tank. It takes T1 time to decrease the height of water to Hη(η>1), and it takes T2 time to take out the rest of the water. If T1=T2, then the value of η is
Answer» A large tank is filled with water to a height $H$ . A small hole is made at the base of the tank. It takes $T_{1}$ time to decrease the height of water to $\frac{H}{η} (η > 1),$ and it takes $T_{2}$ time to take out the rest of the water. If $T_{1} = T_{2},$ then the value of $η$ is

Discussion

11608.	Definition for coulamb's law and superposition law?
Answer» Definition for coulamb's law and superposition law?

Discussion

11609.	Radiation coming from transitions n=2 to n=1 of hydrogen atoms fall on He+ ions in n=1 and n=2 states. The possible transition of helium ions as they absorb energy from the radiation is
Answer» Radiation coming from transitions $n = 2$ to $n = 1$ of hydrogen atoms fall on $H e^{+}$ ions in $n = 1$ and $n = 2$ states. The possible transition of helium ions as they absorb energy from the radiation is

Discussion

11610.	the position of a particle is given by r=3ti-2t^2 j+4k m where t is second and r is meter .a)find the expression for instantaneous velocity and instantaneous acceleration of the particle .
Answer» the position of a particle is given by r=3ti-2t^2 j+4k m where t is second and r is meter . a)find the expression for instantaneous velocity and instantaneous acceleration of the particle .

Discussion

11611.	Light of wavelength 4000∘A is incident on a sodium surface for which the threshold wave length of photo – electrons is 5420∘A. The work function of sodium is
Answer» Light of wavelength $4000 \circ A$ is incident on a sodium surface for which the threshold wave length of photo – electrons is $5420 \circ A$ . The work function of sodium is

Discussion

11612.	Why the time period of oscillation of kinetic energy for a harmonic oscillator is half the time period (T) then what will it be for potential energy?
Answer» Why the time period of oscillation of kinetic energy for a harmonic oscillator is half the time period (T) then what will it be for potential energy?

Discussion

11613.	the total no. of lone pair of electrons present inXeF4 i
Answer» the total no. of lone pair of electrons present inXeF4 i

Discussion

11614.	On a glass slab, a beam of light is incident at an angle of 60∘. Few light rays get reflected and others get refracted. If the reflected and the refracted light rays are mutually perpendicular, calculate the refractive index of the glass slab.
Answer» On a glass slab, a beam of light is incident at an angle of $60^{\circ}$ . Few light rays get reflected and others get refracted. If the reflected and the refracted light rays are mutually perpendicular, calculate the refractive index of the glass slab.

Discussion

11615.	The ratio of the amplitudes of electric field and magnetic field gives:
Answer» The ratio of the amplitudes of electric field and magnetic field gives:

Discussion

11616.	An iron rod is subjected to cycles of magnetisation at the rate of 42 Hz. The density of the rod is 8000 kg/m3 and specific heat is 1×10−3 cal/kg ∘C. The rise in temperature per minute, if the area enclosed by the B-H loop corresponds to an energy of 1.33×10−2 J is (the nearest integer).(Assume there is no radiation losses)
Answer» An iron rod is subjected to cycles of magnetisation at the rate of $42 Hz$ . The density of the rod is $8000 {kg/m}^{3}$ and specific heat is $1 \times 10^{- 3} cal/kg^{\circ} C$ . The rise in temperature per $minute$ , if the area enclosed by the $B-H$ loop corresponds to an energy of $1.33 \times 10^{- 2} J$ is (the nearest integer). (Assume there is no radiation losses)

Discussion

11617.	ntwhy on increasing the magnitude of the charges of the ions ,the lattice energy increases?n
Answer» ntwhy on increasing the magnitude of the charges of the ions ,the lattice energy increases?n

Discussion

11618.	The instantaneous angular position of a point on a rotating wheel is given by the equation Θ(t) = 2t3 – 6t2 The torque on the wheel becomes zero at:
Answer» The instantaneous angular position of a point on a rotating wheel is given by the equation Θ(t) = 2t³ – 6t² The torque on the wheel becomes zero at:

11618.

The instantaneous angular position of a point on a rotating wheel is given by the equation Θ(t) = 2t3 – 6t2 The torque on the wheel becomes zero at:

Answer»

The instantaneous angular position of a point on a rotating wheel is given by the equation

Θ(t) = 2t³ – 6t²

The torque on the wheel becomes zero at:

Discussion

11619.	Along the positive direction of x-axis there exists a constant electric field E0. If the electric potential at x=0 is zero, then its value at a point P, positioned at ′x′ m wrt origin will be
Answer» Along the positive direction of x-axis there exists a constant electric field $E_{0}$ . If the electric potential at $x = 0$ is zero, then its value at a point $P$ , positioned at $^{'} x^{'} m$ wrt origin will be

Discussion

11620.	A man loses 20% of his velocity after running through 108 m. If the rate by which he is losing his velocity remains constant, what is the maximum distance he will cover?
Answer» A man loses $20 %$ of his velocity after running through $108 m$ . If the rate by which he is losing his velocity remains constant, what is the maximum distance he will cover?

Discussion

11621.	.4) A small hole is made in a disc of mass M and radius Rat a distance R/4 from centre. The disc is supported at thepeg through this hole. The moment of inertia of disc abouthorizontal peg is
Answer» .4) A small hole is made in a disc of mass M and radius R at a distance R/4 from centre. The disc is supported at the peg through this hole. The moment of inertia of disc about horizontal peg is

Discussion

11622.	a block of metal weighing 2 kg is resting on a frictionless plane. it is struck by a jet of water at a rate of 1 kg/s at a speed of 5m/s. the initial acceleration of the block
Answer» a block of metal weighing 2 kg is resting on a frictionless plane. it is struck by a jet of water at a rate of 1 kg/s at a speed of 5m/s. the initial acceleration of the block

Discussion

11623.	Given radius of earth ‘R’ and length of a day ‘T’ the height of a geostationary satellite is [G – Gravitational constant, M – Mass of earth]
Answer» Given radius of earth ‘R’ and length of a day ‘T’ the height of a geostationary satellite is [G – Gravitational constant, M – Mass of earth]

Discussion

11624.	Two blocks A and B each of mass m are connected by a massless spring of natural length L and spring constant K. The blocks are initially resting on a smooth horizontal floor with the spring at its natural length as shown in figure. A third identical block C also of mass m moves on the floor with a speed v along the line joining A and B and collides elastically with A. Then
Answer» Two blocks A and B each of mass m are connected by a massless spring of natural length L and spring constant K. The blocks are initially resting on a smooth horizontal floor with the spring at its natural length as shown in figure. A third identical block C also of mass m moves on the floor with a speed v along the line joining A and B and collides elastically with A. Then

11624.

Two blocks A and B each of mass m are connected by a massless spring of natural length L and spring constant K. The blocks are initially resting on a smooth horizontal floor with the spring at its natural length as shown in figure. A third identical block C also of mass m moves on the floor with a speed v along the line joining A and B and collides elastically with A. Then

Answer»

Two blocks A and B each of mass m are connected by a massless spring of natural length L and spring constant K. The blocks are initially resting on a smooth horizontal floor with the spring at its natural length as shown in figure. A third identical block C also of mass m moves on the floor with a speed v along the line joining A and B and collides elastically with A. Then

Discussion

11625.	At moderate pressure, the van der Waal's equation is reduced to:
Answer» At moderate pressure, the van der Waal's equation is reduced to:

Discussion

11626.	What is the angle between plane of eddy currents and the plane of magnetic field?
Answer» What is the angle between plane of eddy currents and the plane of magnetic field?

Discussion

11627.	A hollow sphere of radius 2 m is projected horizontally along a rough surface with velocity v0 and angular velocity ω0. Find out their ratio so that the sphere stops moving after some time.
Answer» A hollow sphere of radius $2 m$ is projected horizontally along a rough surface with velocity $v_{0}$ and angular velocity $ω_{0}$ . Find out their ratio so that the sphere stops moving after some time.

Discussion

11628.	Magnetic flux ϕ (in Webers) linked with a closed circuit of resisitance 100 Ω varies with time t (in seconds) as ϕ=5t2−4t+1. The induced current in the circuit at t=0.2 sec is
Answer» Magnetic flux $ϕ$ (in Webers) linked with a closed circuit of resisitance $100 Ω$ varies with time $t$ (in seconds) as $ϕ = 5 t^{2} - 4 t + 1$ . The induced current in the circuit at $t = 0.2 sec$ is

Discussion

11629.	A car of mass m is moving along a circular track ofradius r with a speed which increases linearly with timet as v = kt where k is a constant. The instantaneouspower delivered by agent applying the force ismt(1) mkt(2)k(3) mk2t(4) mt2k
Answer» A car of mass m is moving along a circular track ofradius r with a speed which increases linearly with timet as v = kt where k is a constant. The instantaneouspower delivered by agent applying the force ismt(1) mkt(2)k(3) mk2t(4) mt2k

Discussion

11630.	a particle moving towards east enters a magntic field directed towards north and deflected towards vertically downward direction . the charged particled is?
Answer» a particle moving towards east enters a magntic field directed towards north and deflected towards vertically downward direction . the charged particled is?

Discussion

11631.	A block of mass 10 kg is dropped from a height 4.05m on a heap of sand. If the sand offers a uniform deceleration of 300m/s^2 to the block , the time taken by the block to come to rest inside sand will be
Answer» A block of mass 10 kg is dropped from a height 4.05m on a heap of sand. If the sand offers a uniform deceleration of 300m/s^2 to the block , the time taken by the block to come to rest inside sand will be

Discussion

11632.	A man standing on a platform observes that the frequency of the sound of a whistle emitted by a moving train is less by 140 Hz that the frequency emitted when the train is stationary. If the velocity of sound in air is 330 m/s and the speed of the train is 70 m/s, the frequency of the whistle is
Answer» A man standing on a platform observes that the frequency of the sound of a whistle emitted by a moving train is less by $140 Hz$ that the frequency emitted when the train is stationary. If the velocity of sound in air is $330 m/s$ and the speed of the train is $70 m/s$ , the frequency of the whistle is

Discussion

11633.	an open flask contains air at 27^° C at what temperature it must be heated to expel out one fourth of the ai
Answer» an open flask contains air at 27^° C at what temperature it must be heated to expel out one fourth of the ai

Discussion

11634.	51.A particle moves in a straight line so that t2=x2-1.Then acceleration is equal to
Answer» 51.A particle moves in a straight line so that t2=x2-1.Then acceleration is equal to

Discussion

11635.	a far sighted man cannot focus distinctly on object closer than 1m. the power of lens that will permit him to read from a dis†an ce of 40 cm is
Answer» a far sighted man cannot focus distinctly on object closer than 1m. the power of lens that will permit him to read from a dis†an ce of 40 cm is

Discussion

11636.	A particle is revolving in a circular path of radius 2 metre with constant angular speed of 4 Radian per second the angular acceleration of the particle is
Answer» A particle is revolving in a circular path of radius 2 metre with constant angular speed of 4 Radian per second the angular acceleration of the particle is

Discussion

11637.	N TUPE SEMICONDUCTOR ARE A.+VE B.-VE C.NEUTRAL D.ALL
Answer» N TUPE SEMICONDUCTOR ARE A.+VE B.-VE C.NEUTRAL D.ALL

Discussion

11638.	Find ddx of y=tan x.
Answer» Find $\frac{d}{d x}$ of $y = t a n x$ .

Discussion

11639.	24.Explain centre of mass briefly and torque briefly
Answer» 24.Explain centre of mass briefly and torque briefly

Discussion

11640.	When a dipole is rotated in an electric field from 90 to some angle (theta) .why does potential energy is -ve ,eventhough potential energy is increased
Answer» When a dipole is rotated in an electric field from 90 to some angle (theta) .why does potential energy is -ve ,eventhough potential energy is increased

Discussion

11641.	Write nuclear reaction equations for(i) α-decay of 22688 Ra (ii) α-decay of 24294 Pu(iii) β–-decay of 3215 P (iv) β–-decay of 21083 Bi(v) β+-decay of 116 C (vi) β+-decay of 9743 Tc(vii) Electron capture of 12054 Xe
Answer» Write nuclear reaction equations for(i) α-decay of 22688 Ra (ii) α-decay of 24294 Pu(iii) β–-decay of 3215 P (iv) β–-decay of 21083 Bi(v) β+-decay of 116 C (vi) β+-decay of 9743 Tc(vii) Electron capture of 12054 Xe

Discussion

11642.	An object is moving with velocity u and attained the velocity v in time t. If a is the acceleration of the object, then derive the equation for position-time using appropriate graph.
Answer» An object is moving with velocity u and attained the velocity v in time t. If a is the acceleration of the object, then derive the equation for position-time using appropriate graph.

Discussion

11643.	When a plane harmonic wave of wavelength λ travels in a medium, the particle speed will always be less than the wave if amplitude is,
Answer» When a plane harmonic wave of wavelength $λ$ travels in a medium, the particle speed will always be less than the wave if amplitude is,

Discussion

11644.	An object is displaced from point A(2,1) m to a point B(0,4) m under the influence of a force →F=−2x^i+3^j. The workdone by this force is
Answer» An object is displaced from point $A (2, 1) m$ to a point $B (0, 4) m$ under the influence of a force $\to F = - 2 x^i + 3^j .$ The workdone by this force is

Discussion

11645.	Two identical straight wires are stretched so as to produce 6 beats per second when vibrating simultaneously. On changing the tension slightly in one of them, the beat frequency remains unchanged. Denoting by T1,T2 the higher and the lower initial tension in the strings, then it could be said that while making the above changes in tension :
Answer» Two identical straight wires are stretched so as to produce 6 beats per second when vibrating simultaneously. On changing the tension slightly in one of them, the beat frequency remains unchanged. Denoting by $T_{1}, T_{2}$ the higher and the lower initial tension in the strings, then it could be said that while making the above changes in tension :

Discussion

11646.	Two particles are executing SHM with the same amplitude and frequency, but with a phase difference, and the maximum separation found is equal to amplitude. What is the phase difference?
Answer» Two particles are executing SHM with the same amplitude and frequency, but with a phase difference, and the maximum separation found is equal to amplitude. What is the phase difference?

Discussion

11647.	The power set of set A = {1, 2} is ____________.
Answer» The power set of set A = {1, 2} is ____________.

Discussion

11648.	What role did lycopodium powder play in volumetric and it's uses
Answer» What role did lycopodium powder play in volumetric and it's uses

Discussion

11649.	10.When an arrow is released from the bow then the end behind is the nearest to the ground,then why doesn't the arrow fall erect on the ground
Answer» 10.When an arrow is released from the bow then the end behind is the nearest to the ground,then why doesn't the arrow fall erect on the ground

Discussion

11650.	The value of kinetic energy of an electron revolving around the orbit of a hydrogen atom is given as KZe²/2r.What does'K' stand for in this expression?
Answer» The value of kinetic energy of an electron revolving around the orbit of a hydrogen atom is given as KZe²/2r. What does'K' stand for in this expression?

Discussion

Explore topic-wise InterviewSolutions in .

Two identical sound waves S1 and S2 reach a point P in phase. The resultant loudness at point is √n dB higher than the loudness of S1. Then, the value of n is [Take log102=0.3]

If the vectors →a and →b are not perpendicular and →c and →d are two vectors satisfying →b×→c=→b×→d and →a⋅→d=0⋅ Then the vector →d is equal to(Consider all vectors are non-zero.)

what is mean by velocity and accelaration and magnitude

How range is 4 times the time in projectile?

A ray of light is incident on a plane mirror along a { vector ^ i+^ j . The normal at incidence point is { along ^ i+^ k\cdot The unit vector along the reflected ray is

A large tank is filled with water to a height H. A small hole is made at the base of the tank. It takes T1 time to decrease the height of water to Hη(η&gt;1), and it takes T2 time to take out the rest of the water. If T1=T2, then the value of η is

Definition for coulamb's law and superposition law?

Radiation coming from transitions n=2 to n=1 of hydrogen atoms fall on He+ ions in n=1 and n=2 states. The possible transition of helium ions as they absorb energy from the radiation is

the position of a particle is given by r=3ti-2t^2 j+4k m where t is second and r is meter .a)find the expression for instantaneous velocity and instantaneous acceleration of the particle .

Light of wavelength 4000∘A is incident on a sodium surface for which the threshold wave length of photo – electrons is 5420∘A. The work function of sodium is

Why the time period of oscillation of kinetic energy for a harmonic oscillator is half the time period (T) then what will it be for potential energy?

the total no. of lone pair of electrons present inXeF4 i

On a glass slab, a beam of light is incident at an angle of 60∘. Few light rays get reflected and others get refracted. If the reflected and the refracted light rays are mutually perpendicular, calculate the refractive index of the glass slab.

The ratio of the amplitudes of electric field and magnetic field gives:

ntwhy on increasing the magnitude of the charges of the ions ,the lattice energy increases?n

The instantaneous angular position of a point on a rotating wheel is given by the equation Θ(t) = 2t3 – 6t2 The torque on the wheel becomes zero at:

Along the positive direction of x-axis there exists a constant electric field E0. If the electric potential at x=0 is zero, then its value at a point P, positioned at ′x′ m wrt origin will be

A man loses 20% of his velocity after running through 108 m. If the rate by which he is losing his velocity remains constant, what is the maximum distance he will cover?

.4) A small hole is made in a disc of mass M and radius Rat a distance R/4 from centre. The disc is supported at thepeg through this hole. The moment of inertia of disc abouthorizontal peg is

a block of metal weighing 2 kg is resting on a frictionless plane. it is struck by a jet of water at a rate of 1 kg/s at a speed of 5m/s. the initial acceleration of the block

Given radius of earth ‘R’ and length of a day ‘T’ the height of a geostationary satellite is [G – Gravitational constant, M – Mass of earth]

At moderate pressure, the van der Waal's equation is reduced to:

What is the angle between plane of eddy currents and the plane of magnetic field?

A hollow sphere of radius 2 m is projected horizontally along a rough surface with velocity v0 and angular velocity ω0. Find out their ratio so that the sphere stops moving after some time.

Magnetic flux ϕ (in Webers) linked with a closed circuit of resisitance 100 Ω varies with time t (in seconds) as ϕ=5t2−4t+1. The induced current in the circuit at t=0.2 sec is

A car of mass m is moving along a circular track ofradius r with a speed which increases linearly with timet as v = kt where k is a constant. The instantaneouspower delivered by agent applying the force ismt(1) mkt(2)k(3) mk2t(4) mt2k

a particle moving towards east enters a magntic field directed towards north and deflected towards vertically downward direction . the charged particled is?

A block of mass 10 kg is dropped from a height 4.05m on a heap of sand. If the sand offers a uniform deceleration of 300m/s^2 to the block , the time taken by the block to come to rest inside sand will be

A man standing on a platform observes that the frequency of the sound of a whistle emitted by a moving train is less by 140 Hz that the frequency emitted when the train is stationary. If the velocity of sound in air is 330 m/s and the speed of the train is 70 m/s, the frequency of the whistle is

an open flask contains air at 27^° C at what temperature it must be heated to expel out one fourth of the ai

51.A particle moves in a straight line so that t2=x2-1.Then acceleration is equal to

a far sighted man cannot focus distinctly on object closer than 1m. the power of lens that will permit him to read from a dis†an ce of 40 cm is

A particle is revolving in a circular path of radius 2 metre with constant angular speed of 4 Radian per second the angular acceleration of the particle is

N TUPE SEMICONDUCTOR ARE A.+VE B.-VE C.NEUTRAL D.ALL

Find ddx of y=tan x.

24.Explain centre of mass briefly and torque briefly

When a dipole is rotated in an electric field from 90 to some angle (theta) .why does potential energy is -ve ,eventhough potential energy is increased

Write nuclear reaction equations for(i) α-decay of 22688 Ra (ii) α-decay of 24294 Pu(iii) β–-decay of 3215 P (iv) β–-decay of 21083 Bi(v) β+-decay of 116 C (vi) β+-decay of 9743 Tc(vii) Electron capture of 12054 Xe

An object is moving with velocity u and attained the velocity v in time t. If a is the acceleration of the object, then derive the equation for position-time using appropriate graph.

When a plane harmonic wave of wavelength λ travels in a medium, the particle speed will always be less than the wave if amplitude is,

An object is displaced from point A(2,1) m to a point B(0,4) m under the influence of a force →F=−2x^i+3^j. The workdone by this force is

Two particles are executing SHM with the same amplitude and frequency, but with a phase difference, and the maximum separation found is equal to amplitude. What is the phase difference?

The power set of set A = {1, 2} is ____________.

What role did lycopodium powder play in volumetric and it's uses

10.When an arrow is released from the bow then the end behind is the nearest to the ground,then why doesn't the arrow fall erect on the ground

The value of kinetic energy of an electron revolving around the orbit of a hydrogen atom is given as K*Z*e²/2r.What does'K' stand for in this expression?

A large tank is filled with water to a height H. A small hole is made at the base of the tank. It takes T1 time to decrease the height of water to Hη(η>1), and it takes T2 time to take out the rest of the water. If T1=T2, then the value of η is

The value of kinetic energy of an electron revolving around the orbit of a hydrogen atom is given as KZe²/2r.What does'K' stand for in this expression?