50278 + Interview Questions in Physics

1.	A passenger is travelling inside a train moving at 40 ms−1. His suitcase is kept on the berth. The driver of train applies breaks such that the speed of the train decreases at a constant rate to 20 ms−1 in 4 s. What should be the minimum coefficient of friction between the suitcase and the berth if the suitcase is not to slide during retardation of the train? (Take g=10 m/s2)
Answer» A passenger is travelling inside a train moving at $40 m s^{- 1}$ . His suitcase is kept on the berth. The driver of train applies breaks such that the speed of the train decreases at a constant rate to $20 m s^{- 1}$ in $4 s$ . What should be the minimum coefficient of friction between the suitcase and the berth if the suitcase is not to slide during retardation of the train? (Take $g = 10 m / s^{2}$ )

Discussion

2.	An ideal gas is expanding such that PT= constant. The coefficient of volume expansion of the gas is :
Answer» An ideal gas is expanding such that $P T =$ constant. The coefficient of volume expansion of the gas is :

Discussion

3.	A helicopter lifts a 72 kg astronaut 15 m vertically from the ocean by means of a cable. The acceleration of the astronaut is g10. How much work is done on the astronaut by the force from the helicopter ?
Answer» A helicopter lifts a $72 kg$ astronaut $15 m$ vertically from the ocean by means of a cable. The acceleration of the astronaut is $\frac{g}{10}$ . How much work is done on the astronaut by the force from the helicopter ?

Discussion

4.	A source of emf E=10 V and having negligible internal resistance is connected to a variable resistance. The resistance varies as shown in figure. The total charge that has passed through the resistor R during the time interval from t1 to t2 is
Answer» A source of emf $E = 10 V$ and having negligible internal resistance is connected to a variable resistance. The resistance varies as shown in figure. The total charge that has passed through the resistor $R$ during the time interval from $t_{1}$ to $t_{2}$ is

Discussion

5.	The ionic conductivity of Ba2+ and Cl− at inifnite dilution are 127 and 76 ohm−1 cm2 mol−1 respectively. The equivalent conductivity of BaCl2 at inifinity dilution (in ohm−1 cm2 eq−1) would be:
Answer» The ionic conductivity of $B a^{2 +}$ and $C l^{-}$ at inifnite dilution are 127 and 76 ${ohm}^{- 1} {cm}^{2} {mol}^{- 1}$ respectively. The equivalent conductivity of $B a C l_{2}$ at inifinity dilution (in ${ohm}^{- 1} {cm}^{2} {eq}^{- 1}$ ) would be:

Discussion

6.	A marble block of mass 2 kg lying on ice when given a velocity of 6 m/s is stopped by friction in 10 s. Then the coefficient of friction is
Answer» A marble block of mass $2 k g$ lying on ice when given a velocity of $6 m / s$ is stopped by friction in $10 s$ . Then the coefficient of friction is

Discussion

7.	An infinite number of bricks are placed one over the other as shown in the figure. Each succeeding brick having half the length and breadth of its preceding brick and the mass of each succeeding brick being 14th of the preceding one. Take O as the origin. The x−coordinate of centre of mass of the system of bricks is:
Answer» An infinite number of bricks are placed one over the other as shown in the figure. Each succeeding brick having half the length and breadth of its preceding brick and the mass of each succeeding brick being ${\frac{1}{4}}^{th}$ of the preceding one. Take $O$ as the origin. The $x -$ coordinate of centre of mass of the system of bricks is:

Discussion

8.	The angle turned by a body undergoing circular motion depends on time as θ=(2t2−θ0t3) rad, where θ0 is constant. Then the angular acceleration of the body at t=2 s is
Answer» The angle turned by a body undergoing circular motion depends on time as $θ = (2 t^{2} - θ_{0} t^{3}) rad$ , where $θ_{0}$ is constant. Then the angular acceleration of the body at $t = 2 s$ is

Discussion

9.	Electrons are emitted from an electron gun at almost zero velocity and are accelerated by an electric field E through a distance of 1.0 m. The electrons are now scattered by an atomic hydrogen sample in ground state. What should be the minimum value of E so that red light of wavelength 656.3 nm may be emitted by the hydrogen ?
Answer» Electrons are emitted from an electron gun at almost zero velocity and are accelerated by an electric field E through a distance of 1.0 m. The electrons are now scattered by an atomic hydrogen sample in ground state. What should be the minimum value of E so that red light of wavelength 656.3 nm may be emitted by the hydrogen ?

Discussion

10.	What is Heisenberg uncertainity tell
Answer» What is Heisenberg uncertainity tell

Discussion

11.	A uniform disc of radius R/2 is put over another uniform disc of radius R of same thickness and density. The peripheries of the two disc touch each other. The centre of mass of the system is from centre of big disc
Answer» A uniform disc of radius R/2 is put over another uniform disc of radius R of same thickness and density. The peripheries of the two disc touch each other. The centre of mass of the system is from centre of big disc

Discussion

12.	Two air bubbles in water
Answer» Two air bubbles in water

Discussion

13.	A liquid can easily change its shape but solids cannot because
Answer» A liquid can easily change its shape but solids cannot because

Discussion

14.	Practically how is it possible that a car have a uniform motion on a road with friction even without traffic?
Answer» Practically how is it possible that a car have a uniform motion on a road with friction even without traffic?

Discussion

15.	A mixture of yellow light of wavelength 580nm and blue light of wavelength 450nm is incident normally on an air film of thickness 2.9x10^2 nm. The colour of the first order of reflected light is A. Red B. Blue C. Violet D. Yellow Please also explain what is meant by first order reflected light and how the answer is B.
Answer» A mixture of yellow light of wavelength 580nm and blue light of wavelength 450nm is incident normally on an air film of thickness 2.9x10^2 nm. The colour of the first order of reflected light is A. Red B. Blue C. Violet D. Yellow Please also explain what is meant by first order reflected light and how the answer is B.

15.

A mixture of yellow light of wavelength 580nm and blue light of wavelength 450nm is incident normally on an air film of thickness 2.9x10^2 nm. The colour of the first order of reflected light is A. Red B. Blue C. Violet D. Yellow Please also explain what is meant by first order reflected light and how the answer is B.

Answer»

A mixture of yellow light of wavelength 580nm and blue light of wavelength 450nm is incident normally on an air film of thickness 2.9x10^2 nm. The colour of the first order of reflected light is

A. Red

B. Blue

C. Violet

D. Yellow

Please also explain what is meant by first order reflected light and how the answer is B.

Discussion

16.	A particle is displaced from a position 2^i−^j−^k (m) to another position 3^i+2^j−2^k (m) under the action of a force 2^i+^j−^k (N). The work done by the force is (in Joule):
Answer» A particle is displaced from a position $2^i -^j -^k$ (m) to another position $3^i + 2^j - 2^k$ (m) under the action of a force $2^i +^j -^k$ (N). The work done by the force is (in Joule):

Discussion

17.	Question: A flag is hoisted on the steamer boat.On the basis of the data given below find out the direction of flutter of the flag ⃗vsteamer/water=10√3ms−1 towards North ⃗vwater=5ms−1 towards East ⃗vwind=5ms−1 towards East (Assume the wind does not affect the steamer) i saw the answer i didnt understand the following sentence velocity of flag in the absence of wind is the velocity of flag wrt wind .this will be opposite to the velocity of the steamer
Answer» Question: A flag is hoisted on the steamer boat.On the basis of the data given below find out the direction of flutter of the flag ⃗vsteamer/water=10√3ms−1 towards North ⃗vwater=5ms−1 towards East ⃗vwind=5ms−1 towards East (Assume the wind does not affect the steamer) i saw the answer i didnt understand the following sentence velocity of flag in the absence of wind is the velocity of flag wrt wind .this will be opposite to the velocity of the steamer

17.

Question: A flag is hoisted on the steamer boat.On the basis of the data given below find out the direction of flutter of the flag ⃗vsteamer/water=10√3ms−1 towards North ⃗vwater=5ms−1 towards East ⃗vwind=5ms−1 towards East (Assume the wind does not affect the steamer) i saw the answer i didnt understand the following sentence velocity of flag in the absence of wind is the velocity of flag wrt wind .this will be opposite to the velocity of the steamer

Answer» Question:

A flag is hoisted on the steamer boat.On the basis of the data given below find out the direction of flutter of

the flag

⃗vsteamer/water=10√3ms−1 towards North

⃗vwater=5ms−1 towards East

⃗vwind=5ms−1 towards East

(Assume the wind does not affect the steamer)
i saw the answer i didnt understand the following sentence
velocity of flag in the absence of wind is the velocity of flag wrt wind .this will be opposite to the velocity of the steamer

Discussion

18.	The Young's double slit experiment is performed with blue and with green light of wavelengths 4360 A and 5460 A respectively. If X is the distance of 4th maximum from the central one, then:
Answer» The Young's double slit experiment is performed with blue and with green light of wavelengths 4360 A and 5460 A respectively. If X is the distance of 4th maximum from the central one, then:

Discussion

19.	A body of mass 2 kg has an initial velocity of 3 m/s along OE and it is subjected to a force of 4 N in a direction perpendicular to OE. The magnitude of displacement of the body from O after 4 seconds will be
Answer» A body of mass $2 kg$ has an initial velocity of $3 m / s$ along $O E$ and it is subjected to a force of $4 N$ in a direction perpendicular to $O E$ . The magnitude of displacement of the body from $O$ after 4 seconds will be

Discussion

20.	A positively charged ball hangs from a silk thread. We put a positive test charge q0 at a point and measure Fq0, then it can be predicted that the electric field strength E.
Answer» A positively charged ball hangs from a silk thread. We put a positive test charge $q_{0}$ at a point and measure $\frac{F}{q_{0}}$ , then it can be predicted that the electric field strength E.

Discussion

21.	Why do we calculate enthalpy at constant pressure?
Answer» Why do we calculate enthalpy at constant pressure?

Discussion

22.	What is Nth harmonic frequency
Answer» What is Nth harmonic frequency

Discussion

23.	two identical conducting spheres A and B are separated by a distance greater than their diameters the spheres carry equal charges and electrostatic force between them is F a third identical uncharged sphere C is first brought in contact with A, then with B and finally removed as a result, the electrostatic force between A and B becomes
Answer» two identical conducting spheres A and B are separated by a distance greater than their diameters the spheres carry equal charges and electrostatic force between them is F a third identical uncharged sphere C is first brought in contact with A, then with B and finally removed as a result, the electrostatic force between A and B becomes

Discussion

24.	The maximum speed at which a car can turn round a curve of 400 m radius on a level road is: (Given: coefficient of friction between the tyres and road is 0.1, and g = 10 m/s2)
Answer» The maximum speed at which a car can turn round a curve of 400 m radius on a level road is: (Given: coefficient of friction between the tyres and road is 0.1, and g = 10 m/s²)

Discussion

25.	A wave of frequency 680 Hz has a wave velocity of 340 m/s . Find the distance between two points on a wave whose phase difference is 45∘.
Answer» A wave of frequency $680 Hz$ has a wave velocity of $340 m/s$ . Find the distance between two points on a wave whose phase difference is $45^{\circ} .$

Discussion

26.	A steel wire has a length of 12.0 m and a mass of 2.10 kg. What should be the tension in the wire so that speed of a transverse wave on the wire equals the speed of sound in dry air at 20∘C=343ms−1
Answer» A steel wire has a length of 12.0 m and a mass of 2.10 kg. What should be the tension in the wire so that speed of a transverse wave on the wire equals the speed of sound in dry air at $20^{\circ} C = 343 m s^{- 1}$

Discussion

27.	A bullet is dropped from the same height when another bullet is fired horizontally. They will hit the ground
Answer» A bullet is dropped from the same height when another bullet is fired horizontally. They will hit the ground

Discussion

28.	The magnitude of summation of powers of M,L,T and A in dimensional formula of resistivity of a conductor is. Given R=ρlA, where ρ is the resistivity, l is length and A is area
Answer» The magnitude of summation of powers of $M, L, T$ and $A$ in dimensional formula of resistivity of a conductor is. Given $R = \frac{ρ l}{A}$ , where $ρ$ is the resistivity, $l$ is length and $A$ is area

Discussion

29.	If a particle moves with velocity v(t)=2t2−t m/s, then find the velocity (m/s) of particle at t=3s.
Answer» If a particle moves with velocity $v (t) = 2 t^{2} - t m / s$ , then find the velocity ( $m / s$ ) of particle at $t = 3 s$ .

Discussion

30.	If the momentum of a body is doubled, then its kinetic energy will increase by
Answer» If the momentum of a body is doubled, then its kinetic energy will increase by

Discussion

31.	In the circuit shown in figure, A is a sliding contact which can move over a smooth rod PQ. Resistance per unit length of the rod PQ is 1 ohm per meter .Initially slider is left to the point P and circuit is in the steady state. At t = 0 slider starts moving with constant velocity v =5m/s towards right. Current in the circuit at t = 2sec is
Answer» In the circuit shown in figure, A is a sliding contact which can move over a smooth rod PQ. Resistance per unit length of the rod PQ is 1 ohm per meter .Initially slider is left to the point P and circuit is in the steady state. At t = 0 slider starts moving with constant velocity v =5m/s towards right. Current in the circuit at t = 2sec is

31.

In the circuit shown in figure, A is a sliding contact which can move over a smooth rod PQ. Resistance per unit length of the rod PQ is 1 ohm per meter .Initially slider is left to the point P and circuit is in the steady state. At t = 0 slider starts moving with constant velocity v =5m/s towards right. Current in the circuit at t = 2sec is

Answer»

In the circuit shown in figure, A is a sliding contact which can move over a smooth rod PQ. Resistance per unit length of the rod PQ is 1 ohm per meter .Initially slider is left to the point P and circuit is in the steady state.

At t = 0 slider starts moving with constant velocity v =5m/s towards right. Current in the circuit at t = 2sec is

Discussion

32.	A particle moves under the action of a force →F=α^i+2^j along a line y + x = 1. If work done by the force along the path is zero, then α is
Answer» A particle moves under the action of a force $\to F = α^i + 2^j$ along a line y + x = 1. If work done by the force along the path is zero, then $α$ is

Discussion

33.	A uniform rod AB of length l and mass m is free to rotate about point A. The rod is released from rest in horizontal position. Given that the moment of inertia of the rod about A is ml23. The initial angular acceleration of the rod will be
Answer» A uniform rod $A B$ of length $l$ and mass $m$ is free to rotate about point $A$ . The rod is released from rest in horizontal position. Given that the moment of inertia of the rod about $A$ is $\frac{m l^{2}}{3}$ . The initial angular acceleration of the rod will be

Discussion

34.	A thermally insulated chamber of volume 2v0 is divided by a frictionless piston of area ‘S’ into two equal parts A and B. Part ‘A’ has an ideal gas at pressure P0 and temperature T0 and in part B there is vacuum. A massless spring of force constant k is connected with piston and the wall of the container as shown. Initially spring is unstretched. Gas in chamber A is allowed to expand. Consider the compression in spring to be x0 in equilibrium.
Answer» A thermally insulated chamber of volume $2 v_{0}$ is divided by a frictionless piston of area ‘S’ into two equal parts A and B. Part ‘A’ has an ideal gas at pressure $P_{0}$ and temperature $T_{0}$ and in part B there is vacuum. A massless spring of force constant k is connected with piston and the wall of the container as shown. Initially spring is unstretched. Gas in chamber A is allowed to expand. Consider the compression in spring to be $x_{0}$ in equilibrium.

34.

A thermally insulated chamber of volume 2v0 is divided by a frictionless piston of area ‘S’ into two equal parts A and B. Part ‘A’ has an ideal gas at pressure P0 and temperature T0 and in part B there is vacuum. A massless spring of force constant k is connected with piston and the wall of the container as shown. Initially spring is unstretched. Gas in chamber A is allowed to expand. Consider the compression in spring to be x0 in equilibrium.

Answer»

A thermally insulated chamber of volume $2 v_{0}$ is divided by a frictionless piston of area ‘S’ into two equal parts A and B. Part ‘A’ has an ideal gas at pressure $P_{0}$ and temperature $T_{0}$ and in part B there is vacuum. A massless spring of force constant k is connected with piston and the wall of the container as shown. Initially spring is unstretched. Gas in chamber A is allowed to expand. Consider the compression in spring to be $x_{0}$ in equilibrium.

Discussion

35.	A water jet of area 50 cm2, moving with a velocity of 25 m/s impinges normally on a plate moving with a velocity of 5 m/s in the same direction. If ρω=1000 kg/m3, then the force exerted on the plate will be:
Answer» A water jet of area $50 c m^{2}$ , moving with a velocity of 25 m/s impinges normally on a plate moving with a velocity of 5 m/s in the same direction. If $ρ_{ω} = 1000 k g / m^{3}$ , then the force exerted on the plate will be:

Discussion

36.	A curve has a radius of 50 metres and a banking angle of 15∘. What is the critical speed (the speed for which no friction is required between the car's tyres and the surface) for a car to travel safely on this curve ? Take g=10 m/s2.
Answer» A curve has a radius of $50 metres$ and a banking angle of $15^{\circ}$ . What is the critical speed (the speed for which no friction is required between the car's tyres and the surface) for a car to travel safely on this curve ? Take $g = 10 {m/s}^{2}$ .

Discussion

37.	The T.V transmission tower in Delhi has a height of 240 m. The distance up to which the broadcast can be received (taking the radius of earth to be 6.4×106m) is (in km) :
Answer» The T.V transmission tower in Delhi has a height of $240 m$ . The distance up to which the broadcast can be received (taking the radius of earth to be $6.4 \times 10^{6} m)$ is (in km) :

Discussion

38.	A sphere of mass m and radius r is projected along a straight line in a gravity free space with speed v. If the coefficient of viscosity of the medium in which it moves is 16π, then the distance travelled by the body before it stops is
Answer» A sphere of mass $m$ and radius $r$ is projected along a straight line in a gravity free space with speed $v$ . If the coefficient of viscosity of the medium in which it moves is $\frac{1}{6 π}$ , then the distance travelled by the body before it stops is

Discussion

39.	When the object is self-luminous, the resolving power of a microscope is given by the expression of
Answer» When the object is self-luminous, the resolving power of a microscope is given by the expression of

Discussion

40.	A car approaching a crossing at a speed of 50 m/s blows a horn of frequency 500 Hz when 30 m away from the crossing. The speed of sound in air is 330 m/s. What frequency will be heard by an observer at rest at 40 m from the crossing?
Answer» A car approaching a crossing at a speed of $50 m/s$ blows a horn of frequency $500 Hz$ when $30 m$ away from the crossing. The speed of sound in air is $330 m/s$ . What frequency will be heard by an observer at rest at $40 m$ from the crossing?

Discussion

41.	A block of weight 100 N is suspended by copper and steel wires of same cross sectional area 0.5 cm2 and length √3 m and 1 m respectively. Their other ends are fixed on a ceiling as shown in figure. The angles subtended by copper and steel wires with ceiling are 30o and 60o respectively. If elongation in copper wire is ΔlC and elongation in steel wire is ΔlS, then the ratio ΔlCΔlS is (Young's modulus for copper and steel are 1×1011 N/m2 and 2×1011 N/m2 respectively)
Answer» A block of weight $100$ N is suspended by copper and steel wires of same cross sectional area $0.5 c m^{2}$ and length $\sqrt{3} m$ and $1 m$ respectively. Their other ends are fixed on a ceiling as shown in figure. The angles subtended by copper and steel wires with ceiling are $30^{o}$ and $60^{o}$ respectively. If elongation in copper wire is $Δ l_{C}$ and elongation in steel wire is $Δ l_{S}$ , then the ratio $\frac{Δ l_{C}}{Δ l_{S}}$ is (Young's modulus for copper and steel are $1 \times 10^{11} N / m^{2}$ and $2 \times 10^{11} N / m^{2}$ respectively)

41.

A block of weight 100 N is suspended by copper and steel wires of same cross sectional area 0.5 cm2 and length √3 m and 1 m respectively. Their other ends are fixed on a ceiling as shown in figure. The angles subtended by copper and steel wires with ceiling are 30o and 60o respectively. If elongation in copper wire is ΔlC and elongation in steel wire is ΔlS, then the ratio ΔlCΔlS is (Young's modulus for copper and steel are 1×1011 N/m2 and 2×1011 N/m2 respectively)

Answer»

A block of weight $100$ N is suspended by copper and steel wires of same cross sectional area $0.5 c m^{2}$ and length $\sqrt{3} m$ and $1 m$ respectively. Their other ends are fixed on a ceiling as shown in figure. The angles subtended by copper and steel wires with ceiling are $30^{o}$ and $60^{o}$ respectively. If elongation in copper wire is $Δ l_{C}$ and elongation in steel wire is $Δ l_{S}$ , then the ratio $\frac{Δ l_{C}}{Δ l_{S}}$ is

(Young's modulus for copper and steel are $1 \times 10^{11} N / m^{2}$ and $2 \times 10^{11} N / m^{2}$ respectively)

Discussion

42.	What is the smallest radius of a circular path on which a cyclist can travel with uniform speed of 36 kmh−1, with angle of inclination (from vertical, for cyclist) 45∘ and g=10 ms−2 ?
Answer» What is the smallest radius of a circular path on which a cyclist can travel with uniform speed of $36 k m h^{- 1}$ , with angle of inclination (from vertical, for cyclist) $45^{\circ}$ and $g = 10 m s^{- 2}$ ?

Discussion

43.	Two sources of sound A and B produce waves of 350 Hz. The particle at point P is vibrating under the influence of these two waves. The amplitudes at the point P produced by the two waves are 0.3 mm and 0.4 mm. If AP−BP=25 cm and velocity of sound is 350 m/s, the resultant amplitude of the particle at point P will be
Answer» Two sources of sound $A$ and $B$ produce waves of $350 Hz$ . The particle at point $P$ is vibrating under the influence of these two waves. The amplitudes at the point $P$ produced by the two waves are $0.3 mm$ and $0.4 mm$ . If $A P - B P = 25 cm$ and velocity of sound is $350 m/s$ , the resultant amplitude of the particle at point $P$ will be

Discussion

44.	Find the charge on, the capacitor shown in figure (32-E30).
Answer» Find the charge on, the capacitor shown in figure (32-E30).

44.

Find the charge on, the capacitor shown in figure (32-E30).

Answer»

Find the charge on, the capacitor shown in figure (32-E30).

Discussion

45.	How does refraction make the bottom of a glass filled with water appear to be raised when seen from above?
Answer» How does refraction make the bottom of a glass filled with water appear to be raised when seen from above?

Discussion

46.	Three blocks of mass 2 kg,3 kg and 5 kg are tied with three identical strings. The blocks are free to rotate in a vertical circle. The minimum velocity given to the blocks to complete the vertical circle is v1, v2 and v3 respectively then
Answer» Three blocks of mass $2 kg, 3 kg$ and $5 kg$ are tied with three identical strings. The blocks are free to rotate in a vertical circle. The minimum velocity given to the blocks to complete the vertical circle is $v_{1}, v_{2}$ and $v_{3}$ respectively then

Discussion

47.	The position vector of the point which divides the join of points 2→a−3→b and →a+→b in the raito 3 : 1, is (a) 3→a−2→b2 (b) 7→a−8→b4 (c) 3→a4 (d) 5→a4
Answer» The position vector of the point which divides the join of points $2 \to a - 3 \to b a n d \to a + \to b$ in the raito 3 : 1, is (a) $\frac{3 \to a - 2 \to b}{2}$ (b) $\frac{7 \to a - 8 \to b}{4}$ (c) $\frac{3 \to a}{4}$ (d) $\frac{5 \to a}{4}$

47.

The position vector of the point which divides the join of points 2→a−3→b and →a+→b in the raito 3 : 1, is (a) 3→a−2→b2 (b) 7→a−8→b4 (c) 3→a4 (d) 5→a4

Answer»

The position vector of the point which divides the join of points $2 \to a - 3 \to b a n d \to a + \to b$ in the raito 3 : 1, is

(a) $\frac{3 \to a - 2 \to b}{2}$

(b) $\frac{7 \to a - 8 \to b}{4}$

(c) $\frac{3 \to a}{4}$

(d) $\frac{5 \to a}{4}$

Discussion

48.	A ball is dropped along smooth inclined surfaces AB,AC and AD. The velocity acquired at B,C,D be vB,vC and vD respectively. Then
Answer» A ball is dropped along smooth inclined surfaces $A B, A C$ and $A D$ . The velocity acquired at $B, C, D$ be $v_{B}, v_{C}$ and $v_{D}$ respectively. Then

Discussion

49.	A body floats in water with one-third of its volume above the surface of water. If it is placed in oil, it floats with half of its volume above the surface of the oil. The relative density of the oil is
Answer» A body floats in water with one-third of its volume above the surface of water. If it is placed in oil, it floats with half of its volume above the surface of the oil. The relative density of the oil is

Discussion

50.	A horizontal heavy uniform bar of weight 'W' is supported at its ends by two men. At the instant, one of the men lets go off his end of the rod, the other feels the force on his hand changed to
Answer» A horizontal heavy uniform bar of weight 'W' is supported at its ends by two men. At the instant, one of the men lets go off his end of the rod, the other feels the force on his hand changed to

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

An ideal gas is expanding such that PT= constant. The coefficient of volume expansion of the gas is :

A helicopter lifts a 72 kg astronaut 15 m vertically from the ocean by means of a cable. The acceleration of the astronaut is g10. How much work is done on the astronaut by the force from the helicopter ?

A source of emf E=10 V and having negligible internal resistance is connected to a variable resistance. The resistance varies as shown in figure. The total charge that has passed through the resistor R during the time interval from t1 to t2 is

The ionic conductivity of Ba2+ and Cl− at inifnite dilution are 127 and 76 ohm−1 cm2 mol−1 respectively. The equivalent conductivity of BaCl2 at inifinity dilution (in ohm−1 cm2 eq−1) would be:

A marble block of mass 2 kg lying on ice when given a velocity of 6 m/s is stopped by friction in 10 s. Then the coefficient of friction is

The angle turned by a body undergoing circular motion depends on time as θ=(2t2−θ0t3) rad, where θ0 is constant. Then the angular acceleration of the body at t=2 s is

What is Heisenberg uncertainity tell

A uniform disc of radius R/2 is put over another uniform disc of radius R of same thickness and density. The peripheries of the two disc touch each other. The centre of mass of the system is from centre of big disc

Two air bubbles in water

A liquid can easily change its shape but solids cannot because

Practically how is it possible that a car have a uniform motion on a road with friction even without traffic?

A particle is displaced from a position 2^i−^j−^k (m) to another position 3^i+2^j−2^k (m) under the action of a force 2^i+^j−^k (N). The work done by the force is (in Joule):

The Young's double slit experiment is performed with blue and with green light of wavelengths 4360 A and 5460 A respectively. If X is the distance of 4th maximum from the central one, then:

A body of mass 2 kg has an initial velocity of 3 m/s along OE and it is subjected to a force of 4 N in a direction perpendicular to OE. The magnitude of displacement of the body from O after 4 seconds will be

A positively charged ball hangs from a silk thread. We put a positive test charge q0 at a point and measure Fq0, then it can be predicted that the electric field strength E.

Why do we calculate enthalpy at constant pressure?

What is Nth harmonic frequency

The maximum speed at which a car can turn round a curve of 400 m radius on a level road is: (Given: coefficient of friction between the tyres and road is 0.1, and g = 10 m/s2)

A wave of frequency 680 Hz has a wave velocity of 340 m/s . Find the distance between two points on a wave whose phase difference is 45∘.

A steel wire has a length of 12.0 m and a mass of 2.10 kg. What should be the tension in the wire so that speed of a transverse wave on the wire equals the speed of sound in dry air at 20∘C=343ms−1

A bullet is dropped from the same height when another bullet is fired horizontally. They will hit the ground

The magnitude of summation of powers of M,L,T and A in dimensional formula of resistivity of a conductor is. Given R=ρlA, where ρ is the resistivity, l is length and A is area

If a particle moves with velocity v(t)=2t2−t m/s, then find the velocity (m/s) of particle at t=3s.

If the momentum of a body is doubled, then its kinetic energy will increase by

A particle moves under the action of a force →F=α^i+2^j along a line y + x = 1. If work done by the force along the path is zero, then α is

A uniform rod AB of length l and mass m is free to rotate about point A. The rod is released from rest in horizontal position. Given that the moment of inertia of the rod about A is ml23. The initial angular acceleration of the rod will be

A water jet of area 50 cm2, moving with a velocity of 25 m/s impinges normally on a plate moving with a velocity of 5 m/s in the same direction. If ρω=1000 kg/m3, then the force exerted on the plate will be:

A curve has a radius of 50 metres and a banking angle of 15∘. What is the critical speed (the speed for which no friction is required between the car's tyres and the surface) for a car to travel safely on this curve ? Take g=10 m/s2.

The T.V transmission tower in Delhi has a height of 240 m. The distance up to which the broadcast can be received (taking the radius of earth to be 6.4×106m) is (in km) :

A sphere of mass m and radius r is projected along a straight line in a gravity free space with speed v. If the coefficient of viscosity of the medium in which it moves is 16π, then the distance travelled by the body before it stops is

When the object is self-luminous, the resolving power of a microscope is given by the expression of

A car approaching a crossing at a speed of 50 m/s blows a horn of frequency 500 Hz when 30 m away from the crossing. The speed of sound in air is 330 m/s. What frequency will be heard by an observer at rest at 40 m from the crossing?

What is the smallest radius of a circular path on which a cyclist can travel with uniform speed of 36 kmh−1, with angle of inclination (from vertical, for cyclist) 45∘ and g=10 ms−2 ?

Find the charge on, the capacitor shown in figure (32-E30).

How does refraction make the bottom of a glass filled with water appear to be raised when seen from above?

Three blocks of mass 2 kg,3 kg and 5 kg are tied with three identical strings. The blocks are free to rotate in a vertical circle. The minimum velocity given to the blocks to complete the vertical circle is v1, v2 and v3 respectively then

The position vector of the point which divides the join of points 2→a−3→b and →a+→b in the raito 3 : 1, is (a) 3→a−2→b2 (b) 7→a−8→b4 (c) 3→a4 (d) 5→a4

A ball is dropped along smooth inclined surfaces AB,AC and AD. The velocity acquired at B,C,D be vB,vC and vD respectively. Then

A body floats in water with one-third of its volume above the surface of water. If it is placed in oil, it floats with half of its volume above the surface of the oil. The relative density of the oil is

A horizontal heavy uniform bar of weight 'W' is supported at its ends by two men. At the instant, one of the men lets go off his end of the rod, the other feels the force on his hand changed to