Explore topic-wise InterviewSolutions in Current Affairs.

This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.

1.

10. An object 2.5 cm high is placed at a distance of 10 cm from a concave mirror of radius of curvature 30 cm. The size of the image is?

Answer» 10. An object 2.5 cm high is placed at a distance of 10 cm from a concave mirror of radius of curvature 30 cm. The size of the image is?
2.

A certain amount of an ideal gas is initially at a pressure P1 and temperature T1. First, it undergoes an isobaric process 1 - 2 such that T2=3T14. Then, it undergoes an isochoric process 2→3 such that T3=T22. The ratio of the final volume to the initial volume of the ideal gas is

Answer»

A certain amount of an ideal gas is initially at a pressure P1 and temperature T1. First, it undergoes an isobaric process 1 - 2 such that T2=3T14. Then, it undergoes an isochoric process 23 such that T3=T22. The ratio of the final volume to the initial volume of the ideal gas is

3.

Two wires of equal length, one of aluminium and the other of copperhave the same resistance. Which of the two wires is lighter? Hence explain why aluminium wires are preferred for overhead power cables.(rAl = 2.63 × 10–8 W m, rCu = 1.72 × 10–8 W m, Relative density ofAl = 2.7, of Cu = 8.9.)

Answer» Two wires of equal length, one of aluminium and the other of copperhave the same resistance. Which of the two wires is lighter? Hence explain why aluminium wires are preferred for overhead power cables.(rAl = 2.63 × 10–8 W m, rCu = 1.72 × 10–8 W m, Relative density ofAl = 2.7, of Cu = 8.9.)
4.

A particle reaches its highest point when it has covered exactly one half of its horizontal range. The corresponding point on the displacement time graph is characterised by

Answer» A particle reaches its highest point when it has covered exactly one half of its horizontal range. The corresponding point on the displacement time graph is characterised by
5.

10-3 W of 5000 Å Light is directed on a photoelectric cell. If the current in the cell is 0.16 μA, the percentage of incident photons which produce photoelectrons, is

Answer»

10-3 W of 5000 Light is directed on a photoelectric cell. If the current in the cell is 0.16 μA, the percentage of incident photons which produce photoelectrons, is



6.

A long string with a charge of lamda per unit length passes through an imaginary cube of edge a . The maximum flux of the electric field through the cube will be?

Answer» A long string with a charge of lamda per unit length passes through an imaginary cube of edge a . The maximum flux of the electric field through the cube will be?
7.

A stone thrown from a point on the ground at 30∘ to the horizontal to hit another point on the ground 145 m away, fell short by 5 m. A second trial at a different angle (but the same speed) again fell short by the same distance. What was the difference in their flight times ?

Answer»

A stone thrown from a point on the ground at 30 to the horizontal to hit another point on the ground 145 m away, fell short by 5 m. A second trial at a different angle (but the same speed) again fell short by the same distance. What was the difference in their flight times ?

8.

A ball is projected at an angle of 37degree from the ground with a speed 20 m/s. The maximum height achieved by ball is

Answer» A ball is projected at an angle of 37degree from the ground with a speed 20 m/s. The maximum height achieved by ball is
9.

Consider two uniform discs of the same thickness and different radii R1=R and R2=αR, made of the same material. If the ratio of their moments of inertia I1 and I2, respectively, about their axes is I1:I2=1:16, then the value of α is :

Answer»

Consider two uniform discs of the same thickness and different radii R1=R and R2=αR, made of the same material. If the ratio of their moments of inertia I1 and I2, respectively, about their axes is I1:I2=1:16, then the value of α is :

10.

Two particles of equal mass m are moving round a circle of radius r due to their mutual gravitational interaction . Find time period of each particle.

Answer» Two particles of equal mass m are moving round a circle of radius r due to their mutual gravitational interaction . Find time period of each particle.
11.

Let f(x) = sin x + cos x, g(x)=x2−1. Thus g(f(x)) is invertible for x∈

Answer»

Let f(x) = sin x + cos x, g(x)=x21. Thus g(f(x)) is invertible for x

12.

moment of inertia of a hallow sphere of mass M and inner radius R and outer radius 2R having uniform mass distribution about diameter axis is

Answer» moment of inertia of a hallow sphere of mass M and inner radius R and outer radius 2R having uniform mass distribution about diameter axis is
13.

In combination of resistor In series, why voltage drop of all resistor is equal to the voltage supplied at starting

Answer» In combination of resistor In series, why voltage drop of all resistor is equal to the voltage supplied at starting
14.

The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle θ should be

Answer»

The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle θ should be


15.

A square plate of 0.1 m side moves parallel to a second plate with a velocity of 0.1 m/s, both plates being immersed in water. If the viscous force is 0.002 N and the coefficient of viscosity is 0.01 poise, distance between the plates in m is

Answer» A square plate of 0.1 m side moves parallel to a second plate with a velocity of 0.1 m/s, both plates being immersed in water. If the viscous force is 0.002 N and the coefficient of viscosity is 0.01 poise, distance between the plates in m is
16.

A circuit contains two inductors of self-inductance L1 and L2 in series. If M is the mutual inductance, then the effective inductance of the circuit shown will be

Answer»

A circuit contains two inductors of self-inductance L1 and L2 in series. If M is the mutual inductance, then the effective inductance of the circuit shown will be




17.

74.2 identical cylindrical vessels with their bases at same level contains a liquid of density &quotp". The height of the liquid in one vessel is h1 and that in the other vessel is h2. The area of either base is A. The work done by gravity in equalizing the levels when the 2 vessels are connected is____.

Answer» 74.2 identical cylindrical vessels with their bases at same level contains a liquid of density "p". The height of the liquid in one vessel is h1 and that in the other vessel is h2. The area of either base is A. The work done by gravity in equalizing the levels when the 2 vessels are connected is____.
18.

In a simple gear train in shown in figure below, the absolute speeds of different wheels, when wheel 4 is the driver.

Answer»

In a simple gear train in shown in figure below, the absolute speeds of different wheels, when wheel 4 is the driver.






19.

A body is attached to the lower end of a vertical spiral spring and it is gradually lowered to its equilibrium position. This stretches the spring by a length d. If the same body attached to the same spring is allowed to fall suddenly, what would be the maximum stretching in this case?

Answer»

A body is attached to the lower end of a vertical spiral spring and it is gradually lowered to its equilibrium position. This stretches the spring by a length d. If the same body attached to the same spring is allowed to fall suddenly, what would be the maximum stretching in this case?

20.

The value of 0∫−1dxx2+2x+2 is:

Answer»

The value of 01dxx2+2x+2 is:


21.

A circular disc with a groove along its diameter is placed horizontally. A block of mass 1 kg is placed as shown. The coefficient of friction between the block and all surfaces of groove in contact is μ=25. The disc has an acceleration of 25 m/s2 Find the acceleration of the block with respect to disc.

Answer»

A circular disc with a groove along its diameter is placed horizontally. A block of mass 1 kg is placed as shown. The coefficient of friction between the block and all surfaces of groove in contact is μ=25. The disc has an acceleration of 25 m/s2 Find the acceleration of the block with respect to disc.


22.

A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement x is proportional to

Answer»

A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement x is proportional to

23.

A square plate of mass 120 g and edge 5.0 cm rotates about one of the edges. If it has a uniform angular acceleration of 0.2rad/s2, what torque acts on the plate ?

Answer»

A square plate of mass 120 g and edge 5.0 cm rotates about one of the edges. If it has a uniform angular acceleration of 0.2rad/s2, what torque acts on the plate ?

24.

A uniform wire of length L and mass M is stretched between two fixed points,keeping a tension F.A sound of frequency is impressed on it.Then the maximum vibrational energy is existing in the wire whenis equal to

Answer» A uniform wire of length L and mass M is stretched between two fixed points,keeping a tension F.A sound of frequency is impressed on it.Then the maximum vibrational energy is existing in the wire whenis equal to
25.

n identical cells, each of emf E and internal resistance r, are joined in series to form a closed circuit. One of the cells is joined with reversed polarity. The potential difference across each cell, except the cell with the reversed polarity, is 2(ρ−1)En. The value of ρ is(integer only)

Answer» n identical cells, each of emf E and internal resistance r, are joined in series to form a closed circuit. One of the cells is joined with reversed polarity. The potential difference across each cell, except the cell with the reversed polarity, is 2(ρ1)En. The value of ρ is(integer only)
26.

Determine the recoil speed of a deuterium atom when a photon of energy 10.2 eV is emitted in a forward direction.

Answer»

Determine the recoil speed of a deuterium atom when a photon of energy 10.2 eV is emitted in a forward direction.

27.

19. Calculate the energy of one mole Of radiation whose frequency is 5*10to the power 14 Hz

Answer» 19. Calculate the energy of one mole Of radiation whose frequency is 5*10to the power 14 Hz
28.

Show that the altitude of the right circular cone of maximum volume that can be iscribed in a sphere of radius r is 4r3.

Answer»

Show that the altitude of the right circular cone of maximum volume that can be iscribed in a sphere of radius r is 4r3.

29.

A cart is moving horizontally along a staight line with a constant speed 30 m/s. A bullet is to be fired vertically upwards from the moving cart in such a way that it returns to the cart at the same point from where it was fired, after the cart has moved 80 m. At what speed (relative to the cart), the bullet must be fired ? Take g=10 m/s2.

Answer»

A cart is moving horizontally along a staight line with a constant speed 30 m/s. A bullet is to be fired vertically upwards from the moving cart in such a way that it returns to the cart at the same point from where it was fired, after the cart has moved 80 m. At what speed (relative to the cart), the bullet must be fired ? Take g=10 m/s2.

30.

In a rectangle ABCD, BC = 2 AB. The moment of inertia is minimum along axis through

Answer»

In a rectangle ABCD, BC = 2 AB. The moment of inertia is minimum along axis through


31.

If the drift velocity of electrons in a conductor is V, then the drift velocity in another conductor of same material, but double the cross section and carrying half the current of first conductor is.

Answer» If the drift velocity of electrons in a conductor is V, then the drift velocity in another conductor of same material, but double the cross section and carrying half the current of first conductor is.
32.

In which case, can velocity be negative? displacement be negative?

Answer» In which case, can velocity be negative? displacement be negative?
33.

(a) Find the radius of the circular orbit of a satellite moving with an angular speed equal to the angular speed of earth's rotation (b) if the satellite is directly above the north pole at some instant, find the time it takes to come over the equatorial plane. Mass of the earth =6×1024kg.

Answer»

(a) Find the radius of the circular orbit of a satellite moving with an angular speed equal to the angular speed of earth's rotation (b) if the satellite is directly above the north pole at some instant, find the time it takes to come over the equatorial plane. Mass of the earth =6×1024kg.

34.

find the relative error in Z ,if Z=A^4B^{1/3}/CD^{3/2}AND THE percentage error in the measurement of A,B,CandD are 4%,2%,3%,1%

Answer» find the relative error in Z ,if Z=A^4B^{1/3}/CD^{3/2}AND THE percentage error in the measurement of A,B,CandD are 4%,2%,3%,1%
35.

A composite rod of mass '2m' & length '2l' consists of two identical rods joined end to end at P. The composite rod is hinged at one of its ends and is kept horizontal. If it is released from rest, ·Find its angular speed when it becomes vertical

Answer»

A composite rod of mass '2m' & length '2l' consists of two identical rods joined end to end at P. The composite rod is hinged at one of its ends and is kept horizontal. If it is released from rest, ·Find its angular speed when it becomes vertical



36.

PQ is an infinite current carrying conductor. AB and CD are smooth conducting rods on which a conductor EF moves with constant velocity V as shown. The force needed to maintain constant speed of EF is (No gravity is there)

Answer»

PQ is an infinite current carrying conductor. AB and CD are smooth conducting rods on which a conductor EF moves with constant velocity V as shown. The force needed to maintain constant speed of EF is (No gravity is there)



37.

Find the apparent depth of the object, as seen by the observer.[measured from the surface AB]

Answer»

Find the apparent depth of the object, as seen by the observer.

[measured from the surface AB]




38.

A DC series motor gave the following open circuit curve at a speed of 600 rpm.Field current (A)102030406080Open circuit voltage (V)103.5158206230259282Total resistance of armature and field circuit is 1 Ω. The motor is connected to 250 V supply. The speed of motor when the armature current is 40 A is________rpm.(Neglect losses in core and friction, windage loss)547.82

Answer» A DC series motor gave the following open circuit curve at a speed of 600 rpm.



Field current (A)102030406080Open circuit voltage (V)103.5158206230259282



Total resistance of armature and field circuit is 1 Ω. The motor is connected to 250 V supply. The speed of motor when the armature current is 40 A is________rpm.

(Neglect losses in core and friction, windage loss)
  1. 547.82
39.

A wire having uniform linear charge density λ is placed in circular form in 3 quadrants with different polarities as shown in the figure. Let be the electric field at O. Then the angle made by with the line along y-axis is

Answer» A wire having uniform linear charge density λ is placed in circular form in 3 quadrants with different polarities as shown in the figure. Let be the electric field at O. Then the angle made by with the line along y-axis is
40.

A block P of mass m is placed on a frictionless horizontal surface. Another block Q of same mass is kept on P and connected to the wall with the help of a spring of spring constant k as shown in the figure. μs is the coefficient of friction between P and Q. The blocks move together performing SHM of amplitude A. The maximum value of the friction force between P and Q is:

Answer»

A block P of mass m is placed on a frictionless horizontal surface. Another block Q of same mass is kept on P and connected to the wall with the help of a spring of spring constant k as shown in the figure. μs is the coefficient of friction between P and Q. The blocks move together performing SHM of amplitude A. The maximum value of the friction force between P and Q is:



41.

46. What is the fullform of 'z' ?

Answer» 46. What is the fullform of 'z' ?
42.

What is the average molecular mass in dry air (78% N2 and 22%O2​​​​​​)

Answer»

What is the average molecular mass in dry air (78% N2 and 22%O2​​​​​​)

43.

If the temperature of a gas is increased from 27∘ C to 927∘C, the root mean square speed of its molecules

Answer»

If the temperature of a gas is increased from 27 C to 927C, the root mean square speed of its molecules



44.

128.The frequency of the whistle of an engine appears to drop to 2/3rd of its actual value when it passes a stationary observer. Velocity of sound in air is 330m/sec then the speed of engine is

Answer» 128.The frequency of the whistle of an engine appears to drop to 2/3rd of its actual value when it passes a stationary observer. Velocity of sound in air is 330m/sec then the speed of engine is
45.

Differece between resitor and resistivity

Answer» Differece between resitor and resistivity
46.

An electric dipole of moment P is placed in the position of stable equilibrium in uniform electric field of intensity E. It is rotated through an angle θ from the initial position. The potential energy of electric dipole in the final position is

Answer» An electric dipole of moment P is placed in the position of stable equilibrium in uniform electric field of intensity E. It is rotated through an angle θ from the initial position. The potential energy of electric dipole in the final position is
47.

the force of a particle of mass 1kg is depend on displacement as f=4x then frequency of S.H.M is

Answer» the force of a particle of mass 1kg is depend on displacement as f=4x then frequency of S.H.M is
48.

a object of height 6 cm is placed on the principal axis of a concave mirror of focal length f at a distance of 4f the length of the image will be

Answer» a object of height 6 cm is placed on the principal axis of a concave mirror of focal length f at a distance of 4f the length of the image will be
49.

An ideal gas expands isothermally from a volume V1 to V2 to and then compressed to original volume V1 adiabatically. Initial pressure is P1 and final pressure is P3. The total work done is W. Then

Answer»

An ideal gas expands isothermally from a volume V1 to V2 to and then compressed to original volume V1 adiabatically. Initial pressure is P1 and final pressure is P3. The total work done is W. Then


50.

In the figure shown, natural length of the spring =2 m. Force constant k=200 N/m. find the reading of the spring balance if A is kept at rest and B is displaced of the right by 1 m. Take g=10 m/s2

Answer»

In the figure shown, natural length of the spring =2 m. Force constant k=200 N/m. find the reading of the spring balance if A is kept at rest and B is displaced of the right by 1 m. Take g=10 m/s2