3731 + Interview Questions in Physics Page 22 InterviewSolution

1051.	A particle is released from rest from a tower of height 3h. The ratio of times to fall equal heights h i.e., t1:t2:t3 is
Answer» A particle is released from rest from a tower of height $3 h$ . The ratio of times to fall equal heights $h$ i.e., $t_{1} : t_{2} : t_{3}$ is

Discussion

1052.	Morning breakfast gives 5000 cal to a 60 kg person. The efficiency of the person is 30 %. The height upto which the person can climb by using the energy obtained from breakfast is [Take g=10 m/s2]
Answer» Morning breakfast gives $5000 cal$ to a $60 kg$ person. The efficiency of the person is $30 %$ . The height upto which the person can climb by using the energy obtained from breakfast is [Take $g = 10 {m/s}^{2}$ ]

Discussion

1053.	A wheel of radius 30 cm has 8 spokes in it. It is mounted on a fixed axle and spins at 5 rev/s. If an arrow of length 24 cm is to be shot parallel to the axis of the wheel without hitting rim or the spokes of the wheel. What minimum speed the arrow must have? (Ignore the effect of gravity)
Answer» A wheel of radius $30 c m$ has $8$ spokes in it. It is mounted on a fixed axle and spins at $5 r e v / s$ . If an arrow of length $24 c m$ is to be shot parallel to the axis of the wheel without hitting rim or the spokes of the wheel. What minimum speed the arrow must have? (Ignore the effect of gravity)

Discussion

1054.	The moment of Inertia of a solid cylinder of mass 'M' and radius R about its Axis(as shown) is.
Answer» The moment of Inertia of a solid cylinder of mass ' $M$ ' and radius $R$ about its Axis(as shown) is.

1054.

The moment of Inertia of a solid cylinder of mass 'M' and radius R about its Axis(as shown) is.

Answer»

The moment of Inertia of a solid cylinder of mass ' $M$ ' and radius $R$ about its Axis(as shown) is.

Discussion

1055.	A 6-kg weight is fastened to the end of a steel wire of unstreched length 60 cm. It is whirled in a vertical circle and has an angular velocity of 2 revolution per second at the bottom of the circle. The area of cross-section of the wire is 0.05cm2. The elongation of the wire when the weight is at the lowest point of the path is (Ysteel=2×1011Pa)
Answer» A 6-kg weight is fastened to the end of a steel wire of unstreched length 60 cm. It is whirled in a vertical circle and has an angular velocity of 2 revolution per second at the bottom of the circle. The area of cross-section of the wire is $0.05 c m^{2}$ . The elongation of the wire when the weight is at the lowest point of the path is $(Y_{s t e e l} = 2 \times 10^{11} P a)$

Discussion

1056.	Two bodies of masses m1 and m2 are initially at rest at infinite distance apart. They are then allowed to move towards each other under mutual gravitational attraction. Their relative velocity of approach at a separation distance r between them is
Answer» Two bodies of masses $m_{1}$ and $m_{2}$ are initially at rest at infinite distance apart. They are then allowed to move towards each other under mutual gravitational attraction. Their relative velocity of approach at a separation distance r between them is

Discussion

1057.	Two identical containers A and B each of volume V0 are joined by a small pipe. The containers contain identical gases at temperature T0 and pressure P0. Container A is heated to temperature 2T0 while maintaining B at the same temperature. If the common pressure of the gas is P and n1 and n2 are the number of moles of the gas in A and B respectively, then choose the correct option(s):
Answer» Two identical containers $A$ and $B$ each of volume $V_{0}$ are joined by a small pipe. The containers contain identical gases at temperature $T_{0}$ and pressure $P_{0}$ . Container $A$ is heated to temperature $2 T_{0}$ while maintaining $B$ at the same temperature. If the common pressure of the gas is $P$ and $n_{1}$ and $n_{2}$ are the number of moles of the gas in $A$ and $B$ respectively, then choose the correct option(s):

Discussion

1058.	A block of mass m initially at rest is dropped from a height h on to a spring of force constant k. the maximum compression in the spring is x then
Answer» A block of mass m initially at rest is dropped from a height h on to a spring of force constant k. the maximum compression in the spring is x then

Discussion

1059.	Two blocks A and B of mass m and 2m are connected by a massless spring of force constant k. They are placed on a smooth horizontal plane. Spring is stretched by an amount x and then released. The relative velocity of the blocks when the spring comes to its natural length is
Answer» Two blocks $A$ and $B$ of mass $m$ and $2 m$ are connected by a massless spring of force constant $k$ . They are placed on a smooth horizontal plane. Spring is stretched by an amount $x$ and then released. The relative velocity of the blocks when the spring comes to its natural length is

Discussion

1060.	Three forces −→F1=2^i−4^j+5^k, −→F2=^i+3^j−8^k and −→F3=−6^i−10^j+7^k are acting on a particle present on the positive x axis, 5 units away from the origin. The three forces combined displace the body to a point 6ˆi−3ˆj+10ˆk. What is the net work done by the three forces ?
Answer» Three forces $_{1} = 2^i - 4^j + 5^k$ , $_{2} =^i + 3^j - 8^k$ and $_{3} = - 6^i - 10^j + 7^k$ are acting on a particle present on the positive $x$ axis, $5 units$ away from the origin. The three forces combined displace the body to a point $6 ˆ i - 3 ˆ j + 10 ˆ k$ . What is the net work done by the three forces ?

Discussion

1061.	It is possible to project a particle with a given speed in two possible ways so as to have the same range, R. The product of the times taken to reach this point in the two possible ways is proportional to
Answer» It is possible to project a particle with a given speed in two possible ways so as to have the same range, R. The product of the times taken to reach this point in the two possible ways is proportional to

Discussion

1062.	N molecules each of mass m of gas A and 2N molecules each of mass 2m of gas B are contained in the same vessel at temperature T. The mean square of the velocity of molecules of gas B is v2 and the mean square of x component of the velocity of molecules of gas A is w2. The ratio w2v2 is
Answer» $N$ molecules each of mass $m$ of gas A and $2 N$ molecules each of mass $2 m$ of gas B are contained in the same vessel at temperature T. The mean square of the velocity of molecules of gas B is $v^{2}$ and the mean square of $x$ component of the velocity of molecules of gas A is $w^{2}$ . The ratio $\frac{w^{2}}{v^{2}}$ is

Discussion

1063.	250 gm of water and equal volume of alcohol of mass 200 gm are replaced successively in the same calorimeter which cools from 60∘C to 55∘C in 130 seconds and 67 seconds respectively. If the water equivalent of the calorimeter is 10 gm, then the specific heat of alcohol (in cal/g ∘C) is(Assume that rate of heat loss in both the cases remains same)
Answer» $250 gm$ of water and equal volume of alcohol of mass $200 gm$ are replaced successively in the same calorimeter which cools from $60^{\circ} C$ to $55^{\circ} C$ in $130$ seconds and $67$ seconds respectively. If the water equivalent of the calorimeter is $10 gm$ , then the specific heat of alcohol (in ${cal/g}^{\circ} C$ ) is (Assume that rate of heat loss in both the cases remains same)

Discussion

1064.	The masses of 10 kg and 20 kg respectively are connected by a massless spring as shown in figure. A force of 200 N acts on the 20 kg mass. At the instant shown, the 10 kg mass has acceleration 12 m/sec2. What is the acceleration of 20 kg mass
Answer» The masses of 10 kg and 20 kg respectively are connected by a massless spring as shown in figure. A force of 200 N acts on the 20 kg mass. At the instant shown, the 10 kg mass has acceleration $12 m / s e c^{2} .$ What is the acceleration of 20 kg mass

Discussion

1065.	The velocity v and displacement x of a particle executing simple harmonic motion are related asvdvdx=−ω2xAt x=0,v=v0. Find the velocity v when the displacement becomes x.
Answer» The velocity v and displacement x of a particle executing simple harmonic motion are related as $v \frac{d v}{d x} = - ω^{2} x$ At $x = 0, v = v_{0}$ . Find the velocity v when the displacement becomes x.

1065.

The velocity v and displacement x of a particle executing simple harmonic motion are related asvdvdx=−ω2xAt x=0,v=v0. Find the velocity v when the displacement becomes x.

Answer»

The velocity v and displacement x of a particle executing simple harmonic motion are related as

$v \frac{d v}{d x} = - ω^{2} x$

At $x = 0, v = v_{0}$ . Find the velocity v when the displacement becomes x.

Discussion

1066.	Two springs have their force constant as k1 and k2(k1>k2) . When they are stretched by the same force
Answer» Two springs have their force constant as $k_{1}$ and $k_{2} (k_{1} > k_{2})$ . When they are stretched by the same force

1066.

Two springs have their force constant as k1 and k2(k1>k2) . When they are stretched by the same force

Answer»

Two springs have their force constant as $k_{1}$ and $k_{2} (k_{1} > k_{2})$ . When they are stretched by the same force

Discussion

1067.	A moving coil galvanometer is converted into an ammeter reading upto 0.03 A by connecting a shunt of resistance 4r across it and into an ammeter reading upto 0.06 A when a shunt of resistance r connected across it. What is the maximum current which can be sent through this galvanometer if no shunt is used.
Answer» A moving coil galvanometer is converted into an ammeter reading upto 0.03 A by connecting a shunt of resistance 4r across it and into an ammeter reading upto 0.06 A when a shunt of resistance r connected across it. What is the maximum current which can be sent through this galvanometer if no shunt is used.

Discussion

1068.	The value of γ=CPCV is 43 for an adiabatic process of an ideal gas for which the internal energy is given by dU=n(VdP+PdV). The value of n is
Answer» The value of $γ = \frac{C_{P}}{C_{V}}$ is $\frac{4}{3}$ for an adiabatic process of an ideal gas for which the internal energy is given by $d U = n (V d P + P d V)$ . The value of $n$ is

Discussion

1069.	The temperature co-efficient of resistance of a wire is 0.00125/∘C. At 300 K , it’s resistance is 1Ω. The resistance of the wire will be 2Ω at
Answer» The temperature co-efficient of resistance of a wire is $0.00125 /^{\circ} C$ . At 300 K , it’s resistance is $1 Ω$ . The resistance of the wire will be $2 Ω$ at

Discussion

1070.	Find the maximum frequency of the X-rays emitted by an X-ray tube operating at 30KV.
Answer» Find the maximum frequency of the X-rays emitted by an X-ray tube operating at 30KV.

Discussion

1071.	The surface mass density of a disc of radius a varies with radial distance r as σ=A+Br where A & B are positive constants. Then, moment of inertia of the disc about an axis passing through its centre and perpendicular to the plane (in kg m2) is:
Answer» The surface mass density of a disc of radius $a$ varies with radial distance $r$ as $σ = A + B r$ where A & B are positive constants. Then, moment of inertia of the disc about an axis passing through its centre and perpendicular to the plane (in ${kg m}^{2}$ ) is:

Discussion

1072.	If pressure is assumed to be constant, at what temperature will the rms speed of gas molecules increase by 10% of the rms speed at STP?
Answer» If pressure is assumed to be constant, at what temperature will the rms speed of gas molecules increase by $10 %$ of the rms speed at STP?

Discussion

1073.	A particle falls from a height h upon a fixed horizontal plane and rebounds. If e is the coefficient of restitution, the total distance travelled before rebounding has stopped is
Answer» A particle falls from a height h upon a fixed horizontal plane and rebounds. If e is the coefficient of restitution, the total distance travelled before rebounding has stopped is

Discussion

1074.	A helicopter is flying horizontally at an altitude of 2 km with a speed of 100 ms−1. A packet is dropped from it. The horizontal distance between the point where the packet is dropped and the point where it hits the ground is (g=10 ms−2)
Answer» A helicopter is flying horizontally at an altitude of $2 km$ with a speed of $100 {ms}^{- 1}$ . A packet is dropped from it. The horizontal distance between the point where the packet is dropped and the point where it hits the ground is $(g = 10 {ms}^{- 2})$

Discussion

1075.	A liquid X of density 4.2 g/cm3 is poured upto a height of 12 cm in the right limb of an U-tube which contains mercury. Another liquid Y is poured in the left arm with height 10 cm. If upper level of X and Y are same, then find the density of liquid Y. (Take density of mercury ρHg=13.6 g/cm3)
Answer» A liquid $X$ of density $4.2 {g/cm}^{3}$ is poured upto a height of $12 cm$ in the right limb of an U-tube which contains mercury. Another liquid $Y$ is poured in the left arm with height $10 cm$ . If upper level of $X$ and $Y$ are same, then find the density of liquid $Y$ . (Take density of mercury $ρ_{H g} = 13.6 {g/cm}^{3}$ )

Discussion

1076.	Water pours out at the rate of Q from a tap, into a cylindrical vessel of radius r. find the rate at which the height of water level rises when the height is h.
Answer» Water pours out at the rate of Q from a tap, into a cylindrical vessel of radius r. find the rate at which the height of water level rises when the height is h.

Discussion

1077.	The speed v of a particle moving along a straight line, when it is at a distance x from a fixed point on the line, is given by v2=144−9x2.Choose the wrong option.
Answer» The speed $v$ of a particle moving along a straight line, when it is at a distance $x$ from a fixed point on the line, is given by $v^{2} = 144 - 9 x^{2}$ . Choose the wrong option.

Discussion

1078.	A charge Q is distributed uniformly along a rod of lengths L. The electric field at a distance ‘d’ along its axis from its closer end will be
Answer» A charge Q is distributed uniformly along a rod of lengths L. The electric field at a distance ‘d’ along its axis from its closer end will be

Discussion

1079.	If one face of a prism of angle 30∘ and refractive index μ=√2 is silvered, the incident ray retraces its initial path. The angle of incidence is
Answer» If one face of a prism of angle $30^{\circ}$ and refractive index $μ = \sqrt{2}$ is silvered, the incident ray retraces its initial path. The angle of incidence is

Discussion

1080.	A boy of mass M stands at the edge of a circular platform of radius R capable of rotating freely about its axis. The moment of inertia of the platform about the axis is I. The system is at rest. A friend of the boy throws a ball of mass m with a velocity v horizontally. The boy on the platform catches it when it passes tangentially to the platform. Find the angular velocity of the system after the boy catches the ball.
Answer» A boy of mass $M$ stands at the edge of a circular platform of radius $R$ capable of rotating freely about its axis. The moment of inertia of the platform about the axis is $I$ . The system is at rest. A friend of the boy throws a ball of mass $m$ with a velocity $v$ horizontally. The boy on the platform catches it when it passes tangentially to the platform. Find the angular velocity of the system after the boy catches the ball.

Discussion

1081.	The value of flux due to q through square plate is
Answer» The value of flux due to q through square plate is

Discussion

1082.	Find the acceleration of block A if block C is moving with acceleration a=3 m/s2 as shown in the figure. Assume the surface to be frictionless and pulleys and string ideal. Take g=10 m/s2
Answer» Find the acceleration of block $A$ if block $C$ is moving with acceleration $a = 3 {m/s}^{2}$ as shown in the figure. Assume the surface to be frictionless and pulleys and string ideal. Take $g = 10 m / s^{2}$

Discussion

1083.	In Young's double slit experiment, the fringes are formed at a distance of 1 m from double slit of separation 0.12 mm. Given λ=6000 ∘A. Then the distances of 3rd dark band from the centre of the screen and 3rd bright band from the centre of the screen will be respectively
Answer» In Young's double slit experiment, the fringes are formed at a distance of $1 m$ from double slit of separation $0.12 mm$ . Given $λ = 6000 \circ A$ . Then the distances of 3rd dark band from the centre of the screen and 3rd bright band from the centre of the screen will be respectively

Discussion

1084.	In the figure given below, with what acceleration does the block of mass m will move?(Pulley and strings are massless and frictionless)
Answer» In the figure given below, with what acceleration does the block of mass $m$ will move? (Pulley and strings are massless and frictionless)

Discussion

1085.	If the resultant of all the external forces acting on a system of particles is zero, then from an inertial frame, one can surely say that
Answer» If the resultant of all the external forces acting on a system of particles is zero, then from an inertial frame, one can surely say that

Discussion

1086.	An ideal spring with spring-constant k is hung from the ceiling and a block of mass M is attached to its lower end. The mass is released suddenly with the spring initially unstretched. Then the maximum extension in the spring is
Answer» An ideal spring with spring-constant k is hung from the ceiling and a block of mass M is attached to its lower end. The mass is released suddenly with the spring initially unstretched. Then the maximum extension in the spring is

Discussion

1087.	A tachometer is a device to measure
Answer» A tachometer is a device to measure

Discussion

1088.	Temperature of 2 moles of a monoatomic gas is raised from 250 K to 300 K at a constant pressure. Heat absorbed by the system is close to (give your answer in kJ)
Answer» Temperature of $2 moles$ of a monoatomic gas is raised from $250 K$ to $300 K$ at a constant pressure. Heat absorbed by the system is close to (give your answer in $kJ$ )

Discussion

1089.	The displacement of the particle is given by x=3t2+2t in m. The average speed of the particle in 4 sec is
Answer» The displacement of the particle is given by $x = 3 t^{2} + 2 t$ in $m$ . The average speed of the particle in $4 sec$ is

Discussion

1090.	A car of 100 HP is moving with a constant velocity of 72 km/hour. The forward force exerted by the engine of the car is
Answer» A car of 100 HP is moving with a constant velocity of 72 km/hour. The forward force exerted by the engine of the car is

Discussion

1091.	A body starts from rest and acquires a velocity V in time T. The work done on the body in time t will be proportional to
Answer» A body starts from rest and acquires a velocity $V$ in time $T$ . The work done on the body in time $t$ will be proportional to

Discussion

1092.	The potential energy for a force field →F is given by U(x,y)=sin(x+y). The force acting on the particle of mass m at (0,π4) is
Answer» The potential energy for a force field $\to F$ is given by $U (x, y) = sin (x + y)$ . The force acting on the particle of mass $m$ at $(0, \frac{π}{4})$ is

Discussion

1093.	A charge having magnitude Q is divided into two parts q and (Q-q) which are held a certian distance r apart. The force of repulsion between the two parts will be maximum if the ratio qQ is
Answer» A charge having magnitude Q is divided into two parts q and (Q-q) which are held a certian distance r apart. The force of repulsion between the two parts will be maximum if the ratio $\frac{q}{Q}$ is

Discussion

1094.	A projectile of mass 2 m explodes at the highest point of its path. It breaks into two equal parts. One part retraces its path. Find the distance of the second part from the point of projection when it finally lands on the ground. Given that range of the projectile would be 200 m if no explosion had taken place.
Answer» A projectile of mass $2 m$ explodes at the highest point of its path. It breaks into two equal parts. One part retraces its path. Find the distance of the second part from the point of projection when it finally lands on the ground. Given that range of the projectile would be $200 m$ if no explosion had taken place.

Discussion

1095.	If y=x3, then d2ydx2 is
Answer» If $y = x^{3}$ , then $\frac{d^{2} y}{d x^{2}}$ is

Discussion

1096.	A ball is dropped from a height of 30 m in downward direction on the stationary floor. If the value of coefficient of restitution is 0.6 and ball rebounds back up to the height (h′), find the height (h′) after first collision.(Take g=10 m/s2)
Answer» A ball is dropped from a height of $30 m$ in downward direction on the stationary floor. If the value of coefficient of restitution is $0.6$ and ball rebounds back up to the height $(h^{'})$ , find the height $(h^{'})$ after first collision. (Take $g = 10 {m/s}^{2}$ )

Discussion

1097.	Which of the following cases, a rigid body, necessarily has an angular acceleration.
Answer» Which of the following cases, a rigid body, necessarily has an angular acceleration.

Discussion

1098.	A leaky parallel plate capacitor is filled completely with a material having dielectric constant K=5 and electric conductivity σ=7.4×10–12Ω–1m–1. If the charge on the plate at the instant t=0 is q=8.85μC, then the leakage current at the instant t=12 sec is approximately x×10–1μA where x is (round off to nearest integer)
Answer» A leaky parallel plate capacitor is filled completely with a material having dielectric constant $K = 5$ and electric conductivity $σ = 7.4 \times 10^{- 12} Ω^{- 1} m^{- 1}$ . If the charge on the plate at the instant $t = 0$ is $q = 8.85 μ C$ , then the leakage current at the instant $t = 12 sec$ is approximately $x \times 10^{- 1} μ A$ where $x$ is (round off to nearest integer)

Discussion

1099.	A vessel of volume V contains an ideal gas at absolute temperature T and pressure P. The gas is allowed to leak till its pressure falls to P. Assuming that the temperature remains constant during leakage, the number of moles of the gas that have leaked is
Answer» A vessel of volume $V$ contains an ideal gas at absolute temperature $T$ and pressure $P$ . The gas is allowed to leak till its pressure falls to $P$ . Assuming that the temperature remains constant during leakage, the number of moles of the gas that have leaked is

Discussion

1100.	Find the ratio of tensions T1 to T2 for the figure shown.
Answer» Find the ratio of tensions $T_{1}$ to $T_{2}$ for the figure shown.

Discussion

Explore topic-wise InterviewSolutions in .

A particle is released from rest from a tower of height 3h. The ratio of times to fall equal heights h i.e., t1:t2:t3 is

Morning breakfast gives 5000 cal to a 60 kg person. The efficiency of the person is 30 %. The height upto which the person can climb by using the energy obtained from breakfast is [Take g=10 m/s2]

A wheel of radius 30 cm has 8 spokes in it. It is mounted on a fixed axle and spins at 5 rev/s. If an arrow of length 24 cm is to be shot parallel to the axis of the wheel without hitting rim or the spokes of the wheel. What minimum speed the arrow must have? (Ignore the effect of gravity)

The moment of Inertia of a solid cylinder of mass 'M' and radius R about its Axis(as shown) is.

Two bodies of masses m1 and m2 are initially at rest at infinite distance apart. They are then allowed to move towards each other under mutual gravitational attraction. Their relative velocity of approach at a separation distance r between them is

A block of mass m initially at rest is dropped from a height h on to a spring of force constant k. the maximum compression in the spring is x then

Two blocks A and B of mass m and 2m are connected by a massless spring of force constant k. They are placed on a smooth horizontal plane. Spring is stretched by an amount x and then released. The relative velocity of the blocks when the spring comes to its natural length is

Three forces −→F1=2^i−4^j+5^k, −→F2=^i+3^j−8^k and −→F3=−6^i−10^j+7^k are acting on a particle present on the positive x axis, 5 units away from the origin. The three forces combined displace the body to a point 6ˆi−3ˆj+10ˆk. What is the net work done by the three forces ?

It is possible to project a particle with a given speed in two possible ways so as to have the same range, R. The product of the times taken to reach this point in the two possible ways is proportional to

N molecules each of mass m of gas A and 2N molecules each of mass 2m of gas B are contained in the same vessel at temperature T. The mean square of the velocity of molecules of gas B is v2 and the mean square of x component of the velocity of molecules of gas A is w2. The ratio w2v2 is

The masses of 10 kg and 20 kg respectively are connected by a massless spring as shown in figure. A force of 200 N acts on the 20 kg mass. At the instant shown, the 10 kg mass has acceleration 12 m/sec2. What is the acceleration of 20 kg mass

The velocity v and displacement x of a particle executing simple harmonic motion are related asvdvdx=−ω2xAt x=0,v=v0. Find the velocity v when the displacement becomes x.

Two springs have their force constant as k1 and k2(k1&gt;k2) . When they are stretched by the same force

The value of γ=CPCV is 43 for an adiabatic process of an ideal gas for which the internal energy is given by dU=n(VdP+PdV). The value of n is

The temperature co-efficient of resistance of a wire is 0.00125/∘C. At 300 K , it’s resistance is 1Ω. The resistance of the wire will be 2Ω at

Find the maximum frequency of the X-rays emitted by an X-ray tube operating at 30KV.

The surface mass density of a disc of radius a varies with radial distance r as σ=A+Br where A &amp; B are positive constants. Then, moment of inertia of the disc about an axis passing through its centre and perpendicular to the plane (in kg m2) is:

If pressure is assumed to be constant, at what temperature will the rms speed of gas molecules increase by 10% of the rms speed at STP?

A particle falls from a height h upon a fixed horizontal plane and rebounds. If e is the coefficient of restitution, the total distance travelled before rebounding has stopped is

A helicopter is flying horizontally at an altitude of 2 km with a speed of 100 ms−1. A packet is dropped from it. The horizontal distance between the point where the packet is dropped and the point where it hits the ground is (g=10 ms−2)

A liquid X of density 4.2 g/cm3 is poured upto a height of 12 cm in the right limb of an U-tube which contains mercury. Another liquid Y is poured in the left arm with height 10 cm. If upper level of X and Y are same, then find the density of liquid Y. (Take density of mercury ρHg=13.6 g/cm3)

Water pours out at the rate of Q from a tap, into a cylindrical vessel of radius r. find the rate at which the height of water level rises when the height is h.

The speed v of a particle moving along a straight line, when it is at a distance x from a fixed point on the line, is given by v2=144−9x2.Choose the wrong option.

A charge Q is distributed uniformly along a rod of lengths L. The electric field at a distance ‘d’ along its axis from its closer end will be

If one face of a prism of angle 30∘ and refractive index μ=√2 is silvered, the incident ray retraces its initial path. The angle of incidence is

The value of flux due to q through square plate is

Find the acceleration of block A if block C is moving with acceleration a=3 m/s2 as shown in the figure. Assume the surface to be frictionless and pulleys and string ideal. Take g=10 m/s2

In Young's double slit experiment, the fringes are formed at a distance of 1 m from double slit of separation 0.12 mm. Given λ=6000 ∘A. Then the distances of 3rd dark band from the centre of the screen and 3rd bright band from the centre of the screen will be respectively

In the figure given below, with what acceleration does the block of mass m will move?(Pulley and strings are massless and frictionless)

If the resultant of all the external forces acting on a system of particles is zero, then from an inertial frame, one can surely say that

An ideal spring with spring-constant k is hung from the ceiling and a block of mass M is attached to its lower end. The mass is released suddenly with the spring initially unstretched. Then the maximum extension in the spring is

A tachometer is a device to measure

Temperature of 2 moles of a monoatomic gas is raised from 250 K to 300 K at a constant pressure. Heat absorbed by the system is close to (give your answer in kJ)

The displacement of the particle is given by x=3t2+2t in m. The average speed of the particle in 4 sec is

A car of 100 HP is moving with a constant velocity of 72 km/hour. The forward force exerted by the engine of the car is

A body starts from rest and acquires a velocity V in time T. The work done on the body in time t will be proportional to

The potential energy for a force field →F is given by U(x,y)=sin(x+y). The force acting on the particle of mass m at (0,π4) is

A charge having magnitude Q is divided into two parts q and (Q-q) which are held a certian distance r apart. The force of repulsion between the two parts will be maximum if the ratio qQ is

If y=x3, then d2ydx2 is

A ball is dropped from a height of 30 m in downward direction on the stationary floor. If the value of coefficient of restitution is 0.6 and ball rebounds back up to the height (h′), find the height (h′) after first collision.(Take g=10 m/s2)

Which of the following cases, a rigid body, necessarily has an angular acceleration.

A vessel of volume V contains an ideal gas at absolute temperature T and pressure P. The gas is allowed to leak till its pressure falls to P. Assuming that the temperature remains constant during leakage, the number of moles of the gas that have leaked is

Find the ratio of tensions T1 to T2 for the figure shown.

Two springs have their force constant as k1 and k2(k1>k2) . When they are stretched by the same force

The surface mass density of a disc of radius a varies with radial distance r as σ=A+Br where A & B are positive constants. Then, moment of inertia of the disc about an axis passing through its centre and perpendicular to the plane (in kg m2) is: