13232 + Interview Questions in Physics Page 125 InterviewSolution

6201.	What is the weight of a block of mass 5 kg at the centre of the Earth? (g=9.8 m s−2)
Answer» What is the weight of a block of mass $5 k g$ at the centre of the Earth? $(g = 9.8 m s^{- 2}$ )

Discussion

6202.	When the inductors are connected in series there are two cases in which they produce emf but the formula are different though both of them are in series why?
Answer» When the inductors are connected in series there are two cases in which they produce emf but the formula are different though both of them are in series why?

Discussion

6203.	Calculate the electric field Intensity at any point an electric dipole.
Answer» Calculate the electric field Intensity at any point an electric dipole.

Discussion

6204.	With what velocity should a particle be projected so that it attains a height equal to radius of Earth ?
Answer» With what velocity should a particle be projected so that it attains a height equal to radius of Earth ?

Discussion

6205.	Explain how, bats use ultrasound to catch the prey.
Answer» Explain how, bats use ultrasound to catch the prey.

Discussion

6206.	A body weighs 40 gf in air, 36.4 gf in liquid and 36 gf in water. Calculate the Relative Density of the liquid.
Answer» A body weighs 40 gf in air, 36.4 gf in liquid and 36 gf in water. Calculate the Relative Density of the liquid.

Discussion

6207.	Read the given statements and select the correct option. Statement1 : If one litre of water at 40C is mixed with one litre of water at 50C, the final temperature of the mixture will be between 40C and 50C. Statement 2: The temperature of mixture of two liquids does not depend on their masses. A. Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1. Both statements 1 and 2 are true, but statement 2 is not the correct explanation of statement 1 C Statement 1 is true but statement 2 is false. D. Statement is false but statement 2 is true.
Answer» Read the given statements and select the correct option. Statement1 : If one litre of water at 40C is mixed with one litre of water at 50C, the final temperature of the mixture will be between 40C and 50C. Statement 2: The temperature of mixture of two liquids does not depend on their masses. A. Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1. Both statements 1 and 2 are true, but statement 2 is not the correct explanation of statement 1 C Statement 1 is true but statement 2 is false. D. Statement is false but statement 2 is true.

Discussion

6208.	An insect moves along the sides of a wall of dimension 12m×5m, starting from one corner and reaches the diagonally opposite corner. If the insect takes 2s for its motion, then find the ratio of average speed to average velocity of insect.
Answer» An insect moves along the sides of a wall of dimension $12 m \times 5 m$ , starting from one corner and reaches the diagonally opposite corner. If the insect takes $2 s$ for its motion, then find the ratio of average speed to average velocity of insect.

Discussion

6209.	Boy A sings with a frequency n and B sings with a frequency 1/8 th of A. If the intensity of sound is same and the displacement amplitude of the sound wave produced by A is a, then the displacement amplitude of the sound wave produced by B will be
Answer» Boy $A$ sings with a frequency $n$ and $B$ sings with a frequency $1 / 8 th$ of $A$ . If the intensity of sound is same and the displacement amplitude of the sound wave produced by $A$ is $a$ , then the displacement amplitude of the sound wave produced by $B$ will be

Discussion

6210.	Why acceleration due to gravity is zero when a satellite revolves around the earth? Why it experiences zero gravity or weightlessness?
Answer» Why acceleration due to gravity is zero when a satellite revolves around the earth? Why it experiences zero gravity or weightlessness?

Discussion

6211.	If a force is applied on a wheel at a point as shown in the figure which makes it roll on the ground, then where is the force of friction acting? [2 MARKS]
Answer» If a force is applied on a wheel at a point as shown in the figure which makes it roll on the ground, then where is the force of friction acting? [2 MARKS]

6211.

If a force is applied on a wheel at a point as shown in the figure which makes it roll on the ground, then where is the force of friction acting? [2 MARKS]

Answer»

If a force is applied on a wheel at a point as shown in the figure which makes it roll on the ground, then where is the force of friction acting? [2 MARKS]

Discussion

6212.	When a horse exerts a force on cart , the cart exerts an equal and opposite force on the horse. Then how come the horse can manage to pull the cart ?
Answer» When a horse exerts a force on cart , the cart exerts an equal and opposite force on the horse. Then how come the horse can manage to pull the cart ?

Discussion

6213.	Why electrochemical cell become dead after some time?
Answer» Why electrochemical cell become dead after some time?

Discussion

6214.	What is the radius of the sun?
Answer» What is the radius of the sun?

Discussion

6215.	Identify the equipment inside a nuclear reactor that limits the chain reaction.
Answer» Identify the equipment inside a nuclear reactor that limits the chain reaction.

Discussion

6216.	66.From ray diagram show the (1) image formation by concave lens for the object at focus. (2) image formation by concave lens for the virtual object at focus
Answer» 66.From ray diagram show the (1) image formation by concave lens for the object at focus. (2) image formation by concave lens for the virtual object at focus

Discussion

6217.	A radioactive nuclide is produced at the constant rate of n per second. It decays into a stable nucleus with decay constant λ. If N0 is a number of nuclei at t=0, then expected number N of nuclei in existence after t seconds is given by
Answer» A radioactive nuclide is produced at the constant rate of $n$ per second. It decays into a stable nucleus with decay constant $λ$ . If $N_{0}$ is a number of nuclei at $t = 0$ , then expected number $N$ of nuclei in existence after $t$ seconds is given by

Discussion

6218.	1)A balloon when kept in sun,bursts after some time.why?
Answer» 1)A balloon when kept in sun,bursts after some time.why?

Discussion

6219.	An object of mass 150 g is moving with a speed of 30 m s−1. It is brought at rest by an external force in 0.5 seconds . Find the magnitude of change in the momentum of the object.
Answer» An object of mass $150 g$ is moving with a speed of $30 m s^{- 1}$ . It is brought at rest by an external force in $0.5 s e c o n d s$ . Find the magnitude of change in the momentum of the object.

Discussion

6220.	What is the current (I) in the circuit?
Answer» What is the current $(I)$ in the circuit?

Discussion

6221.	What are longitudinal waves?
Answer» What are longitudinal waves?

Discussion

6222.	How much momentum will a dumb-bell of mass 10 kg transfer to the floor if it falls from a height of 80 cm? Take its downward acceleration to be 10m/s2
Answer» How much momentum will a dumb-bell of mass 10 kg transfer to the floor if it falls from a height of 80 cm? Take its downward acceleration to be 10m/s²

Discussion

6223.	P27 A circular hole of radius r at the bottom of an initially full watercontainer is sealed by a ball of mass m and radius R. The depth of thewater is now slowly reduced, and when it reaches a certain value, ho the ballrises out of the hole. Find ho.
Answer» P27 A circular hole of radius r at the bottom of an initially full watercontainer is sealed by a ball of mass m and radius R. The depth of thewater is now slowly reduced, and when it reaches a certain value, ho the ballrises out of the hole. Find ho.

Discussion

6224.	Convex mirror m is half.when object placed at 60cm.where should object placed show that size of image becomes 1/4th of size of object
Answer» Convex mirror m is half.when object placed at 60cm.where should object placed show that size of image becomes 1/4th of size of object

Discussion

6225.	The equivalent resistance of a circuit that has two equal resistances in parallel is 2 ohms. Find the value of each resistance.
Answer» The equivalent resistance of a circuit that has two equal resistances in parallel is 2 ohms. Find the value of each resistance.

Discussion

6226.	Question 2The radius of curvature of a spherical mirror is 20 cm. What is its focal length?
Answer» Question 2 The radius of curvature of a spherical mirror is 20 cm. What is its focal length?

Discussion

6227.	In how much time (in seconds) should a charge of 10 C flow between the two terminals so as to maintain a constant current of 100 A?
Answer» In how much time (in seconds) should a charge of $10 C$ flow between the two terminals so as to maintain a constant current of $100 A$ ?

Discussion

6228.	Two concentric rings of radius R = 8 cm andr2 cm having charge 8HC andq uCare placed as shown in diagram. Then electric fieldis zero at axis of rings(1) x = \pm 4/3 cmSC(2) x=24 cm(3) x 2 cm(4) x= \pm 2,6 cm
Answer» Two concentric rings of radius R = 8 cm andr2 cm having charge 8HC andq uCare placed as shown in diagram. Then electric fieldis zero at axis of rings(1) x = \pm 4/3 cmSC(2) x=24 cm(3) x 2 cm(4) x= \pm 2,6 cm

Discussion

6229.	What is the position of the body in the time interval 60-70 seconds?
Answer» What is the position of the body in the time interval 60-70 seconds?

6229.

What is the position of the body in the time interval 60-70 seconds?

Answer»

What is the position of the body in the time interval 60-70 seconds?

Discussion

6230.	A cylindrical vessel of base radius 1 m and height 2m is completely filled with liquid of density 2 x 10 3 kg/m3. Ignore the atmospheric pressure and find the thrust at the bottom of the cylinder.
Answer» A cylindrical vessel of base radius 1 m and height 2m is completely filled with liquid of density 2 x 10 $^{3}$ kg/m $^{3}$ . Ignore the atmospheric pressure and find the thrust at the bottom of the cylinder.

Discussion

6231.	The potential difference across a wire of cross-sectional area 10−3 cm2 and 50 cm length is 2 V, when a current of 0.25 A flows through the wire. The conductivity of the material is
Answer» The potential difference across a wire of cross-sectional area $10^{- 3} {cm}^{2}$ and $50 cm$ length is $2 V$ , when a current of $0.25 A$ flows through the wire. The conductivity of the material is

Discussion

6232.	26.A car moves with constant velocity then accelerates and return back then accelerate then retards then moves with constant velocity and reaches to its initial position. So draw its Velocity-Time ( V-T ) graph ?
Answer» 26.A car moves with constant velocity then accelerates and return back then accelerate then retards then moves with constant velocity and reaches to its initial position. So draw its Velocity-Time ( V-T ) graph ?

Discussion

6233.	Donald Duck conducted experiment to test the conductivity of two liquids A and B by using the tester with magnetic needle. Current is passed through both the liquids and it is found that magnetic needle deflected more in case of Liquid B. Which among these liquids is a poor conductor and why?
Answer» Donald Duck conducted experiment to test the conductivity of two liquids A and B by using the tester with magnetic needle. Current is passed through both the liquids and it is found that magnetic needle deflected more in case of Liquid B. Which among these liquids is a poor conductor and why?

6233.

Donald Duck conducted experiment to test the conductivity of two liquids A and B by using the tester with magnetic needle. Current is passed through both the liquids and it is found that magnetic needle deflected more in case of Liquid B. Which among these liquids is a poor conductor and why?

Answer»

Donald Duck conducted experiment to test the conductivity of two liquids A and B by using the tester with magnetic needle. Current is passed through both the liquids and it is found that magnetic needle deflected more in case of Liquid B. Which among these liquids is a poor conductor and why?

Discussion

6234.	Growth and decay of current in a circuit
Answer» Growth and decay of current in a circuit

Discussion

6235.	Question 1 (b)The following is the distance-time table of an object in motion:Time in secondsDistance in metres001128327464512562167343(b) What do you infer about the forces acting on the object?
Answer» Question 1 (b) The following is the distance-time table of an object in motion: $\begin{matrix} T i m e i n s e c o n d s & D i s t a n c e i n m e t r e s 0 & 0 1 & 1 2 & 8 3 & 27 4 & 64 5 & 125 6 & 216 7 & 343 \end{matrix}$ (b) What do you infer about the forces acting on the object?

Discussion

6236.	Why echoes can't be heard in a small room?
Answer» Why echoes can't be heard in a small room?

Discussion

6237.	A stone is dropped from the of the roof.It passes a window 2m high 0.1s.How far is the roof above above the window? (g=10 m/s2)
Answer» A stone is dropped from the of the roof.It passes a window 2m high 0.1s.How far is the roof above above the window? (g=10 m/s²)

Discussion

6238.	A cylinder of relative density ρr<1 and height h floats in water with its axis vertical. The height of cylinder submerged is .
Answer» A cylinder of relative density $ρ_{r} < 1$ and height $h$ floats in water with its axis vertical. The height of cylinder submerged is .

Discussion

6239.	A particle is projected vertically up with velocity v=\sqrt{4gRe/3 }from earth surface. The velocity ofparticle at height equal to half of the maximum4g R3height reached by it \sqrt{}gRe/2 \sqrt[{}]{}gR/3 2g Re3(3) VgRe
Answer» A particle is projected vertically up with velocity v=\sqrt{4gRe/3 }from earth surface. The velocity ofparticle at height equal to half of the maximum4g R3height reached by it \sqrt{}gRe/2 \sqrt[{}]{}gR/3 2g Re3(3) VgRe

Discussion

6240.	A boy is standing on the edge of the roof at a height 78.4 m. He throws a ball vertically upwards with velocity 19.6 m/s. After how much time (in s) the ball will reach the ground? (Take a = 9.8 m/s2 downwards)
Answer» A boy is standing on the edge of the roof at a height 78.4 m. He throws a ball vertically upwards with velocity 19.6 m/s. After how much time (in s) the ball will reach the ground? (Take a = 9.8 $m / s^{2}$ downwards)

Discussion

6241.	A projectile is thrown from the top of atower of height 15 m, with speed 10 ms1, obliquely at an angle such that itlands upon the ground at maximumdistance x from the foot of tower, thevalue of x is
Answer» A projectile is thrown from the top of atower of height 15 m, with speed 10 ms1, obliquely at an angle such that itlands upon the ground at maximumdistance x from the foot of tower, thevalue of x is

Discussion

6242.	A child is moving on a skateboard at the speed of 2 ms−1. After a force acts on him, his speed becomes 3 ms−1. Calculate the work done by the force, if the weight of the child is 20 kg.
Answer» A child is moving on a skateboard at the speed of $2 {m s}^{- 1}$ . After a force acts on him, his speed becomes $3 {m s}^{- 1}$ . Calculate the work done by the force, if the weight of the child is $20 k g$ .

Discussion

6243.	Minimum time interval for hearing a distinct echo is
Answer» Minimum time interval for hearing a distinct echo is

Discussion

6244.	A ball is thrown upwards with a velocity of 10 ms−1. Find the maximum height reached by the ball. Take acceleration due to gravity g=10 ms−2.
Answer» A ball is thrown upwards with a velocity of $10 m s^{- 1}$ . Find the maximum height reached by the ball. Take acceleration due to gravity $g = 10 {m s}^{- 2}$ .

Discussion

6245.	A cylinder of mass 20 kg is immersed in the water. It weighs 8 kg in the water. If the area of cross-section is 5 m2, then find out the length of cylinder.(Density of water (ρw)=1000 kg m−3,g=10 m s−2)
Answer» A cylinder of mass $20 k g$ is immersed in the water. It weighs $8 k g$ in the water. If the area of cross-section is $5 m^{2}$ , then find out the length of cylinder. (Density of water ( $ρ_{w}$ ) $= 1000 k g m^{- 3}, g = 10 m s^{- 2}$ )

Discussion

6246.	Why are objects weightless, when they are in free fall ?
Answer» Why are objects weightless, when they are in free fall ?

Discussion

6247.	Two stones are thrown vertically upward simultaneously with their initial velocities u1 and u2 respectively. Prove that the heights reached by them would be in the ratio of u1²:u2².
Answer» Two stones are thrown vertically upward simultaneously with their initial velocities u1 and u2 respectively. Prove that the heights reached by them would be in the ratio of u1²:u2².

Discussion

6248.	If y is the instantaneous thickness of ice formed on the surface of a lake in winter than the rate of formation of ice is directly proportional to 1 ) y2) y^23) 1/y4) 1/y^2
Answer» If y is the instantaneous thickness of ice formed on the surface of a lake in winter than the rate of formation of ice is directly proportional to 1 ) y 2) y^2 3) 1/y 4) 1/y^2

Discussion

6249.	13. In SHM, Why the Time period for \|U-K\| is T/4? Where U=potential energy, K =Kinetic Energy. The difference of thier magnitude is taken.
Answer» 13. In SHM, Why the Time period for \|U-K\| is T/4? Where U=potential energy, K =Kinetic Energy. The difference of thier magnitude is taken.

Discussion

6250.	a bullet of masd 50g moving with an intial velocity 100m/s,strikes awooden block and comes to rest after penetrating a distance 2cm in it .calculate: 1)initial momentum of the bullet 2) final momentum of rhe bullet , 3)retardation caused by the wooden block ,and 4) resistive force exerted by the wooden block
Answer» a bullet of masd 50g moving with an intial velocity 100m/s,strikes awooden block and comes to rest after penetrating a distance 2cm in it .calculate: 1)initial momentum of the bullet 2) final momentum of rhe bullet , 3)retardation caused by the wooden block ,and 4) resistive force exerted by the wooden block

Discussion

Explore topic-wise InterviewSolutions in .

What is the weight of a block of mass 5 kg at the centre of the Earth? (g=9.8 m s−2)

When the inductors are connected in series there are two cases in which they produce emf but the formula are different though both of them are in series why?

Calculate the electric field Intensity at any point an electric dipole.

With what velocity should a particle be projected so that it attains a height equal to radius of Earth ?

Explain how, bats use ultrasound to catch the prey.

A body weighs 40 gf in air, 36.4 gf in liquid and 36 gf in water. Calculate the Relative Density of the liquid.

An insect moves along the sides of a wall of dimension 12m×5m, starting from one corner and reaches the diagonally opposite corner. If the insect takes 2s for its motion, then find the ratio of average speed to average velocity of insect.

Boy A sings with a frequency n and B sings with a frequency 1/8 th of A. If the intensity of sound is same and the displacement amplitude of the sound wave produced by A is a, then the displacement amplitude of the sound wave produced by B will be

Why acceleration due to gravity is zero when a satellite revolves around the earth? Why it experiences zero gravity or weightlessness?

If a force is applied on a wheel at a point as shown in the figure which makes it roll on the ground, then where is the force of friction acting? [2 MARKS]

When a horse exerts a force on cart , the cart exerts an equal and opposite force on the horse. Then how come the horse can manage to pull the cart ?

Why electrochemical cell become dead after some time?

What is the radius of the sun?

Identify the equipment inside a nuclear reactor that limits the chain reaction.

66.From ray diagram show the (1) image formation by concave lens for the object at focus. (2) image formation by concave lens for the virtual object at focus

A radioactive nuclide is produced at the constant rate of n per second. It decays into a stable nucleus with decay constant λ. If N0 is a number of nuclei at t=0, then expected number N of nuclei in existence after t seconds is given by

1)A balloon when kept in sun,bursts after some time.why?

An object of mass 150 g is moving with a speed of 30 m s−1. It is brought at rest by an external force in 0.5 seconds . Find the magnitude of change in the momentum of the object.

What is the current (I) in the circuit?

What are longitudinal waves?

How much momentum will a dumb-bell of mass 10 kg transfer to the floor if it falls from a height of 80 cm? Take its downward acceleration to be 10m/s2

P27 A circular hole of radius r at the bottom of an initially full watercontainer is sealed by a ball of mass m and radius R. The depth of thewater is now slowly reduced, and when it reaches a certain value, ho the ballrises out of the hole. Find ho.

Convex mirror m is half.when object placed at 60cm.where should object placed show that size of image becomes 1/4th of size of object

The equivalent resistance of a circuit that has two equal resistances in parallel is 2 ohms. Find the value of each resistance.

Question 2The radius of curvature of a spherical mirror is 20 cm. What is its focal length?

In how much time (in seconds) should a charge of 10 C flow between the two terminals so as to maintain a constant current of 100 A?

Two concentric rings of radius R = 8 cm andr2 cm having charge 8HC andq uCare placed as shown in diagram. Then electric fieldis zero at axis of rings(1) x = \pm 4/3 cmSC(2) x=24 cm(3) x 2 cm(4) x= \pm 2,6 cm

What is the position of the body in the time interval 60-70 seconds?

A cylindrical vessel of base radius 1 m and height 2m is completely filled with liquid of density 2 x 10 3 kg/m3. Ignore the atmospheric pressure and find the thrust at the bottom of the cylinder.

The potential difference across a wire of cross-sectional area 10−3 cm2 and 50 cm length is 2 V, when a current of 0.25 A flows through the wire. The conductivity of the material is

26.A car moves with constant velocity then accelerates and return back then accelerate then retards then moves with constant velocity and reaches to its initial position. So draw its Velocity-Time ( V-T ) graph ?

Donald Duck conducted experiment to test the conductivity of two liquids A and B by using the tester with magnetic needle. Current is passed through both the liquids and it is found that magnetic needle deflected more in case of Liquid B. Which among these liquids is a poor conductor and why?

Growth and decay of current in a circuit

Question 1 (b)The following is the distance-time table of an object in motion:Time in secondsDistance in metres001128327464512562167343(b) What do you infer about the forces acting on the object?

Why echoes can't be heard in a small room?

A stone is dropped from the of the roof.It passes a window 2m high 0.1s.How far is the roof above above the window? (g=10 m/s2)

A cylinder of relative density ρr&lt;1 and height h floats in water with its axis vertical. The height of cylinder submerged is .

A particle is projected vertically up with velocity v=\sqrt{4gRe/3 }from earth surface. The velocity ofparticle at height equal to half of the maximum4g R3height reached by it \sqrt{}gRe/2 \sqrt[{}]{}gR/3 2g Re3(3) VgRe

A boy is standing on the edge of the roof at a height 78.4 m. He throws a ball vertically upwards with velocity 19.6 m/s. After how much time (in s) the ball will reach the ground? (Take a = 9.8 m/s2 downwards)

A projectile is thrown from the top of atower of height 15 m, with speed 10 ms1, obliquely at an angle such that itlands upon the ground at maximumdistance x from the foot of tower, thevalue of x is

A child is moving on a skateboard at the speed of 2 ms−1. After a force acts on him, his speed becomes 3 ms−1. Calculate the work done by the force, if the weight of the child is 20 kg.

Minimum time interval for hearing a distinct echo is

A ball is thrown upwards with a velocity of 10 ms−1. Find the maximum height reached by the ball. Take acceleration due to gravity g=10 ms−2.

A cylinder of mass 20 kg is immersed in the water. It weighs 8 kg in the water. If the area of cross-section is 5 m2, then find out the length of cylinder.(Density of water (ρw)=1000 kg m−3,g=10 m s−2)

Why are objects weightless, when they are in free fall ?

Two stones are thrown vertically upward simultaneously with their initial velocities u1 and u2 respectively. Prove that the heights reached by them would be in the ratio of u1²:u2².

If y is the instantaneous thickness of ice formed on the surface of a lake in winter than the rate of formation of ice is directly proportional to 1 ) y2) y^23) 1/y4) 1/y^2

13. In SHM, Why the Time period for |U-K| is T/4? Where U=potential energy, K =Kinetic Energy. The difference of thier magnitude is taken.

A cylinder of relative density ρr<1 and height h floats in water with its axis vertical. The height of cylinder submerged is .