50278 + Interview Questions in Physics

1.	A uniform rectangular lamina ABCD is of mass M, length a and breadth b, as shown in the figure. If the shaded portion HBGO is cut-off, the coordinates of the centre of mass of the remaining portion will be
Answer» A uniform rectangular lamina $ABCD$ is of mass $M$ , length $a$ and breadth $b$ , as shown in the figure. If the shaded portion $HBGO$ is cut-off, the coordinates of the centre of mass of the remaining portion will be

Discussion

2.	Two stones are thrown up simultaneously with initial speeds u1 and u2(u2>u1). They hit the ground after 6 s and 10 s respectively. Which graph correctly represents the time variation of, Δx=(x2−x1), the relative position of the second stone with respect to the first upto t=10 s? Assume that the stones do not rebound after hitting the ground.
Answer» Two stones are thrown up simultaneously with initial speeds $u_{1}$ and $u_{2} (u_{2} > u_{1})$ . They hit the ground after $6 s$ and $10 s$ respectively. Which graph correctly represents the time variation of, $Δ x = (x_{2} - x_{1})$ , the relative position of the second stone with respect to the first upto $t = 10 s$ ? Assume that the stones do not rebound after hitting the ground.

Discussion

3.	When a soap bubble is charged excess pressure inside it (assume radius does not change) 1) Decreases 2)Increases 3)Does not Change 4)Depends on the nature of cha
Answer» When a soap bubble is charged excess pressure inside it (assume radius does not change) 1) Decreases 2)Increases 3)Does not Change 4)Depends on the nature of cha

Discussion

4.	13.Dimensional formula for angular momentum
Answer» 13.Dimensional formula for angular momentum

Discussion

5.	Plot the graph for potential versus X axis for a uniform charged infinitely long wire.which point will have more potential nearer one or farther one ?
Answer» Plot the graph for potential versus X axis for a uniform charged infinitely long wire.which point will have more potential nearer one or farther one ?

Discussion

6.	A dip needle vibrates in the vertical plane perpendicular to the magnetic meridian. The time period of vibration is found to be x sec. The same needle is then allowed to vibrate in the horizontal plane and the time period is again found to be x sec. Then the tangent of the angle of dip is
Answer» A dip needle vibrates in the vertical plane perpendicular to the magnetic meridian. The time period of vibration is found to be $x sec$ . The same needle is then allowed to vibrate in the horizontal plane and the time period is again found to be $x sec$ . Then the tangent of the angle of dip is

Discussion

7.	The length of the compound microscope is 18 cm. If the magnifying power for the relaxed eye is 28, find the object distance for the objective lens. Focal length of the eyepiece is 4 cm and D=25 cm.
Answer» The length of the compound microscope is $18 cm$ . If the magnifying power for the relaxed eye is 28, find the object distance for the objective lens. Focal length of the eyepiece is $4 cm$ and $D = 25 cm$ .

Discussion

8.	Which of these will travel in a wave along with it?
Answer» Which of these will travel in a wave along with it?

Discussion

9.	What is the reading of the spring balance in the following device?
Answer» What is the reading of the spring balance in the following device?

Discussion

10.	A particle is moving in x−y plane along a path y=x2+x. The ratio vy/vx, when the particle is at (2,6) is,where{vy→ y− component of velocityvx→ x− component of velocity}
Answer» A particle is moving in $x - y$ plane along a path $y = x^{2} + x .$ The ratio $v_{y} / v_{x}$ , when the particle is at $(2, 6)$ is, $where {_{v_{x} \to x - component of velocity}^{v_{y} \to y - component of velocity}}$

Discussion

11.	The figure shows a network of currents. The current i will be
Answer» The figure shows a network of currents. The current $i$ will be

Discussion

12.	The vertical and horizontal components of Earth's magnetic field are 2×10−8 T and 3.46×10−5 T respectively. Calculate the dip at that place.
Answer» The vertical and horizontal components of Earth's magnetic field are $2 \times 10^{- 8} T$ and $3.46 \times 10^{- 5} T$ respectively. Calculate the dip at that place.

Discussion

13.	A potentiometer wire of length L and of resistance r is connected in series with a battery of e.m.f. E0 and a resistance r1. An unknown e.m.f. E is balanced at a length l of the potentiometer wire. The e.m.f. E will be given by
Answer» A potentiometer wire of length $L$ and of resistance $r$ is connected in series with a battery of e.m.f. $E_{0}$ and a resistance $r_{1}$ . An unknown e.m.f. $E$ is balanced at a length $l$ of the potentiometer wire. The e.m.f. $E$ will be given by

Discussion

14.	A charge of 1 C is placed at one end of a non-conducting rod of length 0.6 m. The rod is rotated in a vertical plane about a horizontal axis passing through the other end of the rod with angular frequency 104π rad/s. The magnetic field at a point on the axis of rotation at a distance 0.8 m from centre of the circular path will be:
Answer» A charge of $1 C$ is placed at one end of a non-conducting rod of length $0.6 m$ . The rod is rotated in a vertical plane about a horizontal axis passing through the other end of the rod with angular frequency $10^{4} π rad/s$ . The magnetic field at a point on the axis of rotation at a distance $0.8 m$ from centre of the circular path will be:

Discussion

15.	In the given circuit diagram, when the current reaches steady state in the circuit, the charge on the capacitor of capacitance C will be
Answer» In the given circuit diagram, when the current reaches steady state in the circuit, the charge on the capacitor of capacitance $C$ will be

Discussion

16.	In a meter bridge setup, given that R=10 Ω,X=15 Ω and end error at A, B is 1 cm,3 cm respectively.Find error in measurement of null point, before considering end correction at A and B.
Answer» In a meter bridge setup, given that $R = 10 Ω, X = 15 Ω$ and end error at $A, B$ is $1 cm, 3 cm$ respectively. Find error in measurement of null point, before considering end correction at $A$ and $B$ .

Discussion

17.	10.A metre stick is placed vertically at the origin on a friction less surface. A gentle push in +x direction is given to the top most point of the rod, when it has fallen completely x coordinate of centre of rod is at 1)origin 2)-0.5 m 3) -1 m, 4)+0.5m
Answer» 10.A metre stick is placed vertically at the origin on a friction less surface. A gentle push in +x direction is given to the top most point of the rod, when it has fallen completely x coordinate of centre of rod is at 1)origin 2)-0.5 m 3) -1 m, 4)+0.5m

Discussion

18.	A purely resistive device is rated as 12 A and 120 V for DC supply. If it is connected with an AC supply, V=250sin(30t), find the expression of current(i) flowing in the circuit.
Answer» A purely resistive device is rated as $12 A$ and $120 V$ for DC supply. If it is connected with an AC supply, $V = 250 sin (30 t)$ , find the expression of current $(i)$ flowing in the circuit.

Discussion

19.	Find the inductance between the area enclosed by the two long parallel wires for a unit length, each of radius a, whose centres are at distance d apart and carry equal currents in opposite directions. Neglect the flux within the wire.
Answer» Find the inductance between the area enclosed by the two long parallel wires for a unit length, each of radius $a$ , whose centres are at distance $d$ apart and carry equal currents in opposite directions. Neglect the flux within the wire.

Discussion

20.	Difference between refracting type telescope and reflecting type telescope
Answer» Difference between refracting type telescope and reflecting type telescope

Discussion

21.	An object of mass 8 kg falls through a height of 60 m and by means of a mechanical linkage, rotates a paddle wheel that stirs 0.8 kg of water. Determine the change in temperature of water if initial temperature was 15∘C. Assume no heat is lost to surroundings, specific heat of water, c=4190 J/kg∘C).
Answer» An object of mass $8 kg$ falls through a height of $60 m$ and by means of a mechanical linkage, rotates a paddle wheel that stirs $0.8 kg$ of water. Determine the change in temperature of water if initial temperature was $15^{\circ} C$ . Assume no heat is lost to surroundings, specific heat of water, $c = 4190 J/kg^{\circ} C)$ .

Discussion

22.	How do I understand Neutral Equilibrium? I have understood what it means in terms of Energy diagram. But I have difficulty in understanding the examples of it and differentiating from Stable Equilibrium.
Answer» How do I understand Neutral Equilibrium? I have understood what it means in terms of Energy diagram. But I have difficulty in understanding the examples of it and differentiating from Stable Equilibrium.

22.

How do I understand Neutral Equilibrium? I have understood what it means in terms of Energy diagram. But I have difficulty in understanding the examples of it and differentiating from Stable Equilibrium.

Answer»

How do I understand Neutral Equilibrium?

I have understood what it means in terms of Energy diagram.

But I have difficulty in understanding the examples of it and differentiating from Stable Equilibrium.

Discussion

23.	In a 1 in 40 model of spillway, the velocity is 2 m/sec. The corresponding velocity (in m/sec) in prototype is _______.12.6
Answer» In a $1$ in $40$ model of spillway, the velocity is $2$ $m / s e c$ . The corresponding velocity (in m/sec) in prototype is _______. 12.6

Discussion

24.	Flow of electrons and current in electrolytic cell in internal and external supply.
Answer» Flow of electrons and current in electrolytic cell in internal and external supply.

Discussion

25.	If particle is executing simple harmonic motion with time period T, then the time period of its total mechanical energy is (1) Zero(2)T/2(3) 2T (4) Infinite
Answer» If particle is executing simple harmonic motion with time period T, then the time period of its total mechanical energy is (1) Zero(2)T/2(3) 2T (4) Infinite

Discussion

26.	Time of ascend is equal to time of descend. Does that mean a ball thrown vertically upwards from the top of a building takes the same time to ascend and descend?
Answer» Time of ascend is equal to time of descend. Does that mean a ball thrown vertically upwards from the top of a building takes the same time to ascend and descend?

26.

Time of ascend is equal to time of descend. Does that mean a ball thrown vertically upwards from the top of a building takes the same time to ascend and descend?

Answer»

Time of ascend is equal to time of descend.

Does that mean a ball thrown vertically upwards from the top of a building takes the same time to ascend and descend?

Discussion

27.	The position vector of a particle is determined by the expression →r=3t2^i+4t2^j+7^k. The distance traversed in first 10 sec is
Answer» The position vector of a particle is determined by the expression $\to r = 3 t^{2}^i + 4 t^{2}^j + 7^k$ . The distance traversed in first 10 sec is

Discussion

28.	In an electromagnetic wave, the phase difference between electric and magnetic field vectors →E and →B is-
Answer» In an electromagnetic wave, the phase difference between electric and magnetic field vectors $\to E and \to B$ is-

Discussion

29.	What is the formula for refraction of light at spherical surfaces ?
Answer» What is the formula for refraction of light at spherical surfaces ?

Discussion

30.	A constant force F has been applied upon the plank of mass M. Upon plank, a thin circular wheel of mass m and radius R has been placed. There is no slipping between plank and wheel. The friction force upon wheel will be?
Answer» A constant force F has been applied upon the plank of mass M. Upon plank, a thin circular wheel of mass m and radius R has been placed. There is no slipping between plank and wheel. The friction force upon wheel will be?

Discussion

31.	A spool is pulled at an angle θ with the horizontal on a rough horizontal surface as shown in the figure. If the spool remains at rest, the angle θ is equal to
Answer» A spool is pulled at an angle $θ$ with the horizontal on a rough horizontal surface as shown in the figure. If the spool remains at rest, the angle $θ$ is equal to

Discussion

32.	Two prisms A and B have dispersive powers of 0.012 and 0.018 respectively. The two prisms are incontact with each other. The prism A produces a mean deviation of 1.2∘, what is the mean deviation produced by B if the combination is achromatic?
Answer» Two prisms A and B have dispersive powers of 0.012 and 0.018 respectively. The two prisms are incontact with each other. The prism A produces a mean deviation of ${1.2}^{\circ}$ , what is the mean deviation produced by B if the combination is achromatic?

Discussion

33.	One end of a uniform wire of length L and of weight W is attached rigidly to a point in the roof and a weight W1 is suspended from its lower end. If S is the area of cross-section of the wire, the stress in the wire at a height $\frac{3L}{4}$ from its lower end is
Answer» One end of a uniform wire of length $L$ and of weight $W$ is attached rigidly to a point in the roof and a weight $W_{1}$ is suspended from its lower end. If $S$ is the area of cross-section of the wire, the stress in the wire at a height $\frac{3L}{4}$ from its lower end is

Discussion

34.	When the resistance of 2Ω is connected across the terminal of the cell, the current is 0.5 amp. When the resistance is increased to 5Ω, the current is 0.25 amp. The emf of the cell is
Answer» When the resistance of $2 Ω$ is connected across the terminal of the cell, the current is 0.5 amp. When the resistance is increased to $5 Ω$ , the current is 0.25 amp. The emf of the cell is

Discussion

35.	When a load 10 kg is hung from the wire then extension of 2 m is produced. Then workdone by restoring force is
Answer» When a load 10 kg is hung from the wire then extension of 2 m is produced. Then workdone by restoring force is

Discussion

36.	Two wires A and B of the same material have their lengths in the ratio of 1:2 and their diameters in the ratio of 2:1. If they are stretched with the same force, the ratio of the increase in the length of A to that of B will be
Answer» Two wires A and B of the same material have their lengths in the ratio of 1:2 and their diameters in the ratio of 2:1. If they are stretched with the same force, the ratio of the increase in the length of A to that of B will be

Discussion

37.	A ray of light parallel to y−axis is incident on a parabola y=4x2 polished from inside as shown in the figure. Find the co-ordinates x and y of the point at which the incident ray should fall such that the reflected ray becomes horizontal after reflection.
Answer» A ray of light parallel to $y -$ axis is incident on a parabola $y = 4 x^{2}$ polished from inside as shown in the figure. Find the co-ordinates $x and y$ of the point at which the incident ray should fall such that the reflected ray becomes horizontal after reflection.

Discussion

38.	How to derive the Coulomb's Law?
Answer» How to derive the Coulomb's Law?

Discussion

39.	At what point of a projectile motion acceleration and velocity are perpendicular to each other
Answer» At what point of a projectile motion acceleration and velocity are perpendicular to each other

Discussion

40.	A stationary uniform rod of mass m=1 kg and length l=2 m leans against a smooth vertical wall making an angle θ=45o with rough horizontal floor. Find the frictional force that is exerted by the floor on the rod.
Answer» A stationary uniform rod of mass $m = 1 kg$ and length $l = 2 m$ leans against a smooth vertical wall making an angle $θ = 45^{o}$ with rough horizontal floor. Find the frictional force that is exerted by the floor on the rod.

Discussion

41.	A student arranged an electric circuit as shown alongside:He would observe:(1) no reading in either the ammeter or the voltmeter(2) no reading in the voltmeter but a reading in the ammeter(3) no reading in the ammeter but a reading in the voltmeter(4) readings in both the ammeter and the voltmeter
Answer» A student arranged an electric circuit as shown alongside: He would observe: (1) no reading in either the ammeter or the voltmeter (2) no reading in the voltmeter but a reading in the ammeter (3) no reading in the ammeter but a reading in the voltmeter (4) readings in both the ammeter and the voltmeter

Discussion

42.	74. A body is in limiting equilibrium on a rough inclined plane an angle of 30^° with horizontal. Calculate acceleration with which the body will slide down, when inclination of the plane is changed to 45^° .
Answer» 74. A body is in limiting equilibrium on a rough inclined plane an angle of 30^° with horizontal. Calculate acceleration with which the body will slide down, when inclination of the plane is changed to 45^° .

Discussion

43.	A bullet loses 1/20 of its velocity passing through a plank. what is the least number of plank required to stop the bullets? (all the planks offers the same retardation)
Answer» A bullet loses 1/20 of its velocity passing through a plank. what is the least number of plank required to stop the bullets? (all the planks offers the same retardation)

Discussion

44.	An angular moment of a satellite revolving round the earth in a circular orbit at a height R above the surface is L. Here R is radius of the earth.The magnitude of angular momentum of another satellite of the same mass revolving very close to the surface of the earth is
Answer» An angular moment of a satellite revolving round the earth in a circular orbit at a height $R$ above the surface is $L$ . Here $R$ is radius of the earth.The magnitude of angular momentum of another satellite of the same mass revolving very close to the surface of the earth is

Discussion

45.	In the angle subtended by vector ˆi+ˆj with the x - axis is
Answer» In the angle subtended by vector $ˆ i + ˆ j$ with the x - axis is

Discussion

46.	which is true about piezoelectric crystal ? 1- They produce electric current on heating .2-They produce an electric current when a mechanical stress is applied .3-They produce electric current on cooling. 4-They produce electric current on s†an ding for some times
Answer» which is true about piezoelectric crystal ? 1- They produce electric current on heating .2-They produce an electric current when a mechanical stress is applied .3-They produce electric current on cooling. 4-They produce electric current on s†an ding for some times

Discussion

47.	ge decrease in the acceleration due to gravity when a body is taken from theFind the percesurface of earth to a height of 64 km from its Surface. \lbrack Take R 6.4 x 106 ml2hHint: Use 9.-9
Answer» ge decrease in the acceleration due to gravity when a body is taken from theFind the percesurface of earth to a height of 64 km from its Surface. \lbrack Take R 6.4 x 106 ml2hHint: Use 9.-9

Discussion

48.	52. What is the concept of magnetite,spinal and inverse spinal structures?
Answer» 52. What is the concept of magnetite,spinal and inverse spinal structures?

Discussion

49.	40. There is uniform electric field of 8 i N/C. What is the net flux of the uniform electric field through the cube of side 0.3m oriented so that its faces are parallel to the coordinate plane
Answer» 40. There is uniform electric field of 8 i N/C. What is the net flux of the uniform electric field through the cube of side 0.3m oriented so that its faces are parallel to the coordinate plane

Discussion

50.	There is an electric field E in x− direction. If the work done by electric force on moving a charge of 0.2 C through a distance of 2 m along a line making an angle 60∘ with x− axis is 4 J, then what is the value of E?(Neglect gravity)
Answer» There is an electric field $E$ in $x -$ direction. If the work done by electric force on moving a charge of $0.2 C$ through a distance of $2 m$ along a line making an angle $60^{\circ}$ with $x -$ axis is $4 J$ , then what is the value of $E$ ? (Neglect gravity)

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A uniform rectangular lamina ABCD is of mass M, length a and breadth b, as shown in the figure. If the shaded portion HBGO is cut-off, the coordinates of the centre of mass of the remaining portion will be

When a soap bubble is charged excess pressure inside it (assume radius does not change) 1) Decreases 2)Increases 3)Does not Change 4)Depends on the nature of cha

13.Dimensional formula for angular momentum

Plot the graph for potential versus X axis for a uniform charged infinitely long wire.which point will have more potential nearer one or farther one ?

A dip needle vibrates in the vertical plane perpendicular to the magnetic meridian. The time period of vibration is found to be x sec. The same needle is then allowed to vibrate in the horizontal plane and the time period is again found to be x sec. Then the tangent of the angle of dip is

The length of the compound microscope is 18 cm. If the magnifying power for the relaxed eye is 28, find the object distance for the objective lens. Focal length of the eyepiece is 4 cm and D=25 cm.

Which of these will travel in a wave along with it?

What is the reading of the spring balance in the following device?

A particle is moving in x−y plane along a path y=x2+x. The ratio vy/vx, when the particle is at (2,6) is,where{vy→ y− component of velocityvx→ x− component of velocity}

The figure shows a network of currents. The current i will be

The vertical and horizontal components of Earth's magnetic field are 2×10−8 T and 3.46×10−5 T respectively. Calculate the dip at that place.

A potentiometer wire of length L and of resistance r is connected in series with a battery of e.m.f. E0 and a resistance r1. An unknown e.m.f. E is balanced at a length l of the potentiometer wire. The e.m.f. E will be given by

In the given circuit diagram, when the current reaches steady state in the circuit, the charge on the capacitor of capacitance C will be

In a meter bridge setup, given that R=10 Ω,X=15 Ω and end error at A, B is 1 cm,3 cm respectively.Find error in measurement of null point, before considering end correction at A and B.

10.A metre stick is placed vertically at the origin on a friction less surface. A gentle push in +x direction is given to the top most point of the rod, when it has fallen completely x coordinate of centre of rod is at 1)origin 2)-0.5 m 3) -1 m, 4)+0.5m

A purely resistive device is rated as 12 A and 120 V for DC supply. If it is connected with an AC supply, V=250sin(30t), find the expression of current(i) flowing in the circuit.

Find the inductance between the area enclosed by the two long parallel wires for a unit length, each of radius a, whose centres are at distance d apart and carry equal currents in opposite directions. Neglect the flux within the wire.

Difference between refracting type telescope and reflecting type telescope

How do I understand Neutral Equilibrium? I have understood what it means in terms of Energy diagram. But I have difficulty in understanding the examples of it and differentiating from Stable Equilibrium.

In a 1 in 40 model of spillway, the velocity is 2 m/sec. The corresponding velocity (in m/sec) in prototype is _______.12.6

Flow of electrons and current in electrolytic cell in internal and external supply.

If particle is executing simple harmonic motion with time period T, then the time period of its total mechanical energy is (1) Zero(2)T/2(3) 2T (4) Infinite

Time of ascend is equal to time of descend. Does that mean a ball thrown vertically upwards from the top of a building takes the same time to ascend and descend?

The position vector of a particle is determined by the expression →r=3t2^i+4t2^j+7^k. The distance traversed in first 10 sec is

In an electromagnetic wave, the phase difference between electric and magnetic field vectors →E and →B is-

What is the formula for refraction of light at spherical surfaces ?

A constant force F has been applied upon the plank of mass M. Upon plank, a thin circular wheel of mass m and radius R has been placed. There is no slipping between plank and wheel. The friction force upon wheel will be?

A spool is pulled at an angle θ with the horizontal on a rough horizontal surface as shown in the figure. If the spool remains at rest, the angle θ is equal to

Two prisms A and B have dispersive powers of 0.012 and 0.018 respectively. The two prisms are incontact with each other. The prism A produces a mean deviation of 1.2∘, what is the mean deviation produced by B if the combination is achromatic?

One end of a uniform wire of length L and of weight W is attached rigidly to a point in the roof and a weight W1 is suspended from its lower end. If S is the area of cross-section of the wire, the stress in the wire at a height \(\frac{3L}{4}\) from its lower end is

When the resistance of 2Ω is connected across the terminal of the cell, the current is 0.5 amp. When the resistance is increased to 5Ω, the current is 0.25 amp. The emf of the cell is

When a load 10 kg is hung from the wire then extension of 2 m is produced. Then workdone by restoring force is

Two wires A and B of the same material have their lengths in the ratio of 1:2 and their diameters in the ratio of 2:1. If they are stretched with the same force, the ratio of the increase in the length of A to that of B will be

A ray of light parallel to y−axis is incident on a parabola y=4x2 polished from inside as shown in the figure. Find the co-ordinates x and y of the point at which the incident ray should fall such that the reflected ray becomes horizontal after reflection.

How to derive the Coulomb's Law?

At what point of a projectile motion acceleration and velocity are perpendicular to each other

A stationary uniform rod of mass m=1 kg and length l=2 m leans against a smooth vertical wall making an angle θ=45o with rough horizontal floor. Find the frictional force that is exerted by the floor on the rod.

A student arranged an electric circuit as shown alongside:He would observe:(1) no reading in either the ammeter or the voltmeter(2) no reading in the voltmeter but a reading in the ammeter(3) no reading in the ammeter but a reading in the voltmeter(4) readings in both the ammeter and the voltmeter

74. A body is in limiting equilibrium on a rough inclined plane an angle of 30^° with horizontal. Calculate acceleration with which the body will slide down, when inclination of the plane is changed to 45^° .

A bullet loses 1/20 of its velocity passing through a plank. what is the least number of plank required to stop the bullets? (all the planks offers the same retardation)

An angular moment of a satellite revolving round the earth in a circular orbit at a height R above the surface is L. Here R is radius of the earth.The magnitude of angular momentum of another satellite of the same mass revolving very close to the surface of the earth is

In the angle subtended by vector ˆi+ˆj with the x - axis is

which is true about piezoelectric crystal ? 1- They produce electric current on heating .2-They produce an electric current when a mechanical stress is applied .3-They produce electric current on cooling. 4-They produce electric current on s†an ding for some times

ge decrease in the acceleration due to gravity when a body is taken from theFind the percesurface of earth to a height of 64 km from its Surface. \lbrack Take R 6.4 x 106 ml2hHint: Use 9.-9

52. What is the concept of magnetite,spinal and inverse spinal structures?

40. There is uniform electric field of 8 i N/C. What is the net flux of the uniform electric field through the cube of side 0.3m oriented so that its faces are parallel to the coordinate plane

There is an electric field E in x− direction. If the work done by electric force on moving a charge of 0.2 C through a distance of 2 m along a line making an angle 60∘ with x− axis is 4 J, then what is the value of E?(Neglect gravity)