50278 + Interview Questions in Physics

1.	Find the average velocity of a projective between the instands it crosses half the maximum height. It is projected with a speed u at angle θ with the horizontal.
Answer» Find the average velocity of a projective between the instands it crosses half the maximum height. It is projected with a speed u at angle $θ$ with the horizontal.

Discussion

2.	A capacitore of capacitance 10 μ F is connected to an oscillator giving an output voltage ε = (10 V) sin ω t. Find the peak currents in the circuit for ω = 10 s−1, 100 s−1, 500 s−1, 1000 s−1
Answer» A capacitore of capacitance 10 $μ$ F is connected to an oscillator giving an output voltage $ε$ = (10 V) sin $ω$ t. Find the peak currents in the circuit for $ω$ = 10 $s^{- 1}$ , 100 $s^{- 1}$ , 500 $s^{- 1}$ , 1000 $s^{- 1}$

Discussion

3.	When will the relative velocity of two moving objects is zero?
Answer» When will the relative velocity of two moving objects is zero?

Discussion

4.	A bus traveling the first one third distance at a speed of 10km/hr, next one fourth at 20km/hr and the remaining at 40km/hr. The average speed of the bus is nearly
Answer» A bus traveling the first one third distance at a speed of 10km/hr, next one fourth at 20km/hr and the remaining at 40km/hr. The average speed of the bus is nearly

Discussion

5.	A body is projected from the top of a tower of height 32 m with a velocity of 20 m/s at an angle of 37∘ above the horizontal. Find the horizontal distance travelled before it hits the ground. (Take g=10 m/s2)
Answer» A body is projected from the top of a tower of height $32 m$ with a velocity of $20 m/s$ at an angle of $37^{\circ}$ above the horizontal. Find the horizontal distance travelled before it hits the ground. (Take $g = 10 m / s^{2}$ )

Discussion

6.	The work function of sodium is 2.3 eV. The threshold wavelength of sodium will be
Answer» The work function of sodium is 2.3 eV. The threshold wavelength of sodium will be

Discussion

7.	The maximum stress that can be applied to the material of a wire used to suspend an elevator is 108 Nm−2. If the mass of the elevator is 1000 kg and it moves up with an acceleration of 0.2 ms−2, what is the minimum diameter of the wire required? (Take g=9.8 m/s2)
Answer» The maximum stress that can be applied to the material of a wire used to suspend an elevator is $10^{8} {Nm}^{- 2}$ . If the mass of the elevator is $1000 kg$ and it moves up with an acceleration of $0.2 {ms}^{- 2}$ , what is the minimum diameter of the wire required? (Take $g = 9.8 m / s^{2}$ )

Discussion

8.	A freei pitch ball of mass 6 gram carries a positive charge of (1/3 )* 10 -7 coulomb what must be nature and magnitude of charge that should be given to second pitch ball fixed 5 cm vertically below the former baseball so that the upper bonus stationery.
Answer» A freei pitch ball of mass 6 gram carries a positive charge of (1/3 )* 10 ^-7 coulomb what must be nature and magnitude of charge that should be given to second pitch ball fixed 5 cm vertically below the former baseball so that the upper bonus stationery.

Discussion

9.	The focal length of a double convex lens is equal to radius of curvature of either surface The refractive index of its material is
Answer» The focal length of a double convex lens is equal to radius of curvature of either surface The refractive index of its material is

Discussion

10.	An ant starts from the origin and walks along a straight line. After every second, its position (in mm) is observed by a curious 5-year old. These are his readings: Position (mm) 0 10 40 100 200 After time (s) 0 1 2 3 4 By looking at this table, which of the following could be a possible description of the ant's motion is (a) Uniform velocity (b) uniform acceleration (with non-uniform velocity) (c) Uniform jerk (with non-uniform accelerator) (d) cannot be determined (can be any of the above)
Answer» An ant starts from the origin and walks along a straight line. After every second, its position (in mm) is observed by a curious 5-year old. These are his readings: Position (mm) 0 10 40 100 200 After time (s) 0 1 2 3 4 By looking at this table, which of the following could be a possible description of the ant's motion is (a) Uniform velocity (b) uniform acceleration (with non-uniform velocity) (c) Uniform jerk (with non-uniform accelerator) (d) cannot be determined (can be any of the above)

10.

An ant starts from the origin and walks along a straight line. After every second, its position (in mm) is observed by a curious 5-year old. These are his readings: Position (mm) 0 10 40 100 200 After time (s) 0 1 2 3 4 By looking at this table, which of the following could be a possible description of the ant's motion is (a) Uniform velocity (b) uniform acceleration (with non-uniform velocity) (c) Uniform jerk (with non-uniform accelerator) (d) cannot be determined (can be any of the above)

Answer»

An ant starts from the origin and walks along a straight line. After every second, its position (in mm) is observed by a curious 5-year old. These are his readings:

Position (mm) 0 10 40 100 200

After time (s) 0 1 2 3 4

By looking at this table, which of the following could be a possible description of the ant's motion is

(a) Uniform velocity

(b) uniform acceleration (with non-uniform velocity)

(c) Uniform jerk (with non-uniform accelerator)

(d) cannot be determined (can be any of the above)

Discussion

11.	What is a pseudo force?
Answer» What is a pseudo force?

Discussion

12.	What is lines of force of magnet
Answer» What is lines of force of magnet

Discussion

13.	Particle A makes a perfectly elastic collision with another particle B at rest. After collision, they fly apart in opposite directions with equal speeds. The ratio of masses mAmB is
Answer» Particle $A$ makes a perfectly elastic collision with another particle $B$ at rest. After collision, they fly apart in opposite directions with equal speeds. The ratio of masses $\frac{m_{A}}{m_{B}}$ is

Discussion

14.	What are straight lines ?
Answer» What are straight lines ?

Discussion

15.	There is a fire in the building which started from its rooftop and is rapidly growing. Assuming that the water projected from hose behaves as a projectile, how far from that building should the fire hose be located to hit the highest possible height that it can hit. Given hose pipe is adjusted such that water leaves at a fixed angle with the horizontal at speed u m/s?
Answer» There is a fire in the building which started from its rooftop and is rapidly growing. Assuming that the water projected from hose behaves as a projectile, how far from that building should the fire hose be located to hit the highest possible height that it can hit. Given hose pipe is adjusted such that water leaves at a fixed angle with the horizontal at speed u m/s?

Discussion

16.	A body is thrown vertically upwards. If air resistance is to be taken into account, then the time during which the body rises is
Answer» A body is thrown vertically upwards. If air resistance is to be taken into account, then the time during which the body rises is

16.

A body is thrown vertically upwards. If air resistance is to be taken into account, then the time during which the body rises is

Answer»

A body is thrown vertically upwards. If air resistance is to be taken into account, then the time during which the body rises is

Discussion

17.	An observer moves towards a stationary source of sound with a speed (1/5)th of the speed of sound. The wavelength and frequency of the source emitted are λ and f, respectively. The apparent frequency and wavelength recorded by the observer are, respectively,
Answer» An observer moves towards a stationary source of sound with a speed (1/5)th of the speed of sound. The wavelength and frequency of the source emitted are λ and f, respectively. The apparent frequency and wavelength recorded by the observer are, respectively,

Discussion

18.	A glass window is to be fit in an aluminium frame. The temperature on the working day is 40∘C and the glass window measures exactly 20 c m × 30 cm. What should be the size of the aluminium frame so that there is no stress on the glass in winter even if the temperature drops to 0∘ C ? Coefficients of linear expansion for glass and aluminium are 9.0×10−6 ∘C−1 and 24×10−6 ∘C−1 respectively.
Answer» A glass window is to be fit in an aluminium frame. The temperature on the working day is $40^{\circ} C$ and the glass window measures exactly 20 c m $\times$ 30 cm. What should be the size of the aluminium frame so that there is no stress on the glass in winter even if the temperature drops to $0^{\circ} C$ ? Coefficients of linear expansion for glass and aluminium are $9.0 \times 10^{- 6}^{\circ} C^{- 1}$ and $24 \times 10^{- 6}^{\circ} C^{- 1}$ respectively.

Discussion

19.	What is dielectric constant
Answer» What is dielectric constant

Discussion

20.	An aeroplane is moving in a circular path with a speed 250 km/h what is change in velocity in half revolution
Answer» An aeroplane is moving in a circular path with a speed 250 km/h what is change in velocity in half revolution

Discussion

21.	Whatv is the reason to operate photodiodes in reverse bias?
Answer» Whatv is the reason to operate photodiodes in reverse bias?

Discussion

22.	A long spring is stretched by 2 cm, its potential energy is U. If the spring is stretched by 10 cm, the potential energy stored in it will be
Answer» A long spring is stretched by 2 cm, its potential energy is U. If the spring is stretched by 10 cm, the potential energy stored in it will be

Discussion

23.	A sphere of radius 1cm has potential of 8000V , then energy density near it's surface will be a) 6400000J/m3 b) 8000J/m3 c) 32J/m3 d) 2.83J/m3
Answer» A sphere of radius 1cm has potential of 8000V , then energy density near it's surface will be a) 6400000J/m3 b) 8000J/m3 c) 32J/m3 d) 2.83J/m3

Discussion

24.	What is the difference between the capacitance of a capacitor when they are connected in by a battery and disconnect from the battery
Answer» What is the difference between the capacitance of a capacitor when they are connected in by a battery and disconnect from the battery

Discussion

25.	By what temperature a rod should be heated so that it's length becomes 2l0 if initial length is l0 . Assume that α (coefficient of linear expansion) in that range of temperature remains constant and melting point is very high.
Answer» By what temperature a rod should be heated so that it's length becomes $2 l_{0}$ if initial length is $l_{0}$ . Assume that $α$ (coefficient of linear expansion) in that range of temperature remains constant and melting point is very high.

Discussion

26.	The displacement x of a body moving in a straight line is related to time t as 2x2+3x=t. If v is the velocity of the body at a certain instant of time, its acceleration will be
Answer» The displacement x of a body moving in a straight line is related to time t as $2 x^{2} + 3 x = t$ . If v is the velocity of the body at a certain instant of time, its acceleration will be

Discussion

27.	Find the equivalent resistance of the network shown in figure (45-E8) between the points A and B.
Answer» Find the equivalent resistance of the network shown in figure (45-E8) between the points A and B.

27.

Find the equivalent resistance of the network shown in figure (45-E8) between the points A and B.

Answer»

Find the equivalent resistance of the network shown in figure (45-E8) between the points A and B.

Discussion

28.	Two parallel plane sheets 1 and 2 carry uniform charge densities σ1 and σ2 as in fig electric field in the region marked II is (σ1 > σ2)
Answer» Two parallel plane sheets 1 and 2 carry uniform charge densities $σ_{1}$ and $σ_{2}$ as in fig electric field in the region marked II is ( $σ_{1}$ > $σ_{2}$ )

Discussion

29.	A simple pendulum of length 1 feet suspended from the ceiling of an elevator takes π3 seconds to complete one oscillation. Find the acceleration of the elevator.
Answer» A simple pendulum of length 1 feet suspended from the ceiling of an elevator takes $\frac{π}{3}$ seconds to complete one oscillation. Find the acceleration of the elevator.

Discussion

30.	A rod of length L is placed along the x− axis between x=0 and x=L. The linear density (mass/length) λ of the rod varies with the distance x from the origin as λ=kx2. Here k is a positive constant. Then, the x coordinate of the centre of mass of this rod will be Ln, where n is (Answer upto two decimal places)
Answer» A rod of length $L$ is placed along the $x -$ axis between $x = 0$ and $x = L$ . The linear density (mass/length) $λ$ of the rod varies with the distance $x$ from the origin as $λ = k x^{2}$ . Here $k$ is a positive constant. Then, the x coordinate of the centre of mass of this rod will be $\frac{L}{n}$ , where $n$ is (Answer upto two decimal places)

Discussion

31.	A heavy particle is suspended by a string of length l. The particle is given a horizontal velocity v0. The string becomes slack at some angle and the particle proceeds on a parabola. Find the value of v0 if the particle passes through the point of suspension.
Answer» A heavy particle is suspended by a string of length $l$ . The particle is given a horizontal velocity $v_{0}$ . The string becomes slack at some angle and the particle proceeds on a parabola. Find the value of $v_{0}$ if the particle passes through the point of suspension.

Discussion

32.	What is common for the given two blocks?
Answer» What is common for the given two blocks?

32.

What is common for the given two blocks?

Answer»

What is common for the given two blocks?

Discussion

33.	Hydrogen gas is filled in a balloon at 20∘C. If temperature is made 40∘C, pressure remaining same, what fraction of hydrogen will come out
Answer» Hydrogen gas is filled in a balloon at $20^{\circ} C$ . If temperature is made $40^{\circ} C$ , pressure remaining same, what fraction of hydrogen will come out

Discussion

34.	A hollow sphere rolls without slipping on the horizontal surface such that its translational velocity is v. Find that the maximum height attained by it on an inclined surface as shown in the figure.
Answer» A hollow sphere rolls without slipping on the horizontal surface such that its translational velocity is $v$ . Find that the maximum height attained by it on an inclined surface as shown in the figure.

Discussion

35.	An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?
Answer» An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?

Discussion

36.	A particle is projected at an angle α with the horizontal from the foot of a plane, whose inclination to the horizontal is β. Find the velocity with which the particle strikes perpendicular to the inclined plane.
Answer» A particle is projected at an angle $α$ with the horizontal from the foot of a plane, whose inclination to the horizontal is $β$ . Find the velocity with which the particle strikes perpendicular to the inclined plane.

Discussion

37.	Derivative of f(x)=x2cosx is
Answer» Derivative of $f (x) = \frac{x^{2}}{cos x}$ is

Discussion

38.	The magnetic moment of a bar magnet is 1 joule per tesla. When bar magnet makes 300 with the field, we need a external torque of 3 Nm to hold it. Find the work required to turn it by further 900.
Answer» The magnetic moment of a bar magnet is 1 joule per tesla. When bar magnet makes $30^{0}$ with the field, we need a external torque of $3 N m$ to hold it. Find the work required to turn it by further $90^{0}$ .

Discussion

39.	A pendulum is made from a massless rod of length L and bob of mass m. A spring of force constant k is connected horizontally to it at a distance h below its point of suspension as shown. The rod is in equilibrium in vertical position. The frequency of vibration of the system for small values of θ is :
Answer» A pendulum is made from a massless rod of length L and bob of mass m. A spring of force constant k is connected horizontally to it at a distance h below its point of suspension as shown. The rod is in equilibrium in vertical position. The frequency of vibration of the system for small values of $θ$ is :

39.

A pendulum is made from a massless rod of length L and bob of mass m. A spring of force constant k is connected horizontally to it at a distance h below its point of suspension as shown. The rod is in equilibrium in vertical position. The frequency of vibration of the system for small values of θ is :

Answer»

A pendulum is made from a massless rod of length L and bob of mass m. A spring of force constant k is connected horizontally to it at a distance h below its point of suspension as shown. The rod is in equilibrium in vertical position. The frequency of vibration of the system for small values of $θ$ is :

Discussion

40.	V verus T curves at constant pressures P1 and P2 for an idealgas are shown in the figure,
Answer» V verus T curves at constant pressures $P_{1}$ and $P_{2}$ for an idealgas are shown in the figure,

40.

V verus T curves at constant pressures P1 and P2 for an idealgas are shown in the figure,

Answer»

V verus T curves at constant pressures $P_{1}$ and $P_{2}$ for an idealgas are shown in the figure,

Discussion

41.	A cylindrical vessel filled with water is released on an inclined surface of inclination angle θ as shown in figure. The coefficient of friction between surface with vessel is μ(<tan θ). Then the constant angle made by the surface of water with the incline will be
Answer» A cylindrical vessel filled with water is released on an inclined surface of inclination angle $θ$ as shown in figure. The coefficient of friction between surface with vessel is $μ (< t a n θ)$ . Then the constant angle made by the surface of water with the incline will be

Discussion

42.	A stone tied to the end of a string 80 cm long is whirled in a horizontal circle with a constant speed. If the stone makes 14 revolutions in 25 seconds, what is the magnitude of acceleration of the stone?
Answer» A stone tied to the end of a string $80 cm$ long is whirled in a horizontal circle with a constant speed. If the stone makes 14 revolutions in 25 seconds, what is the magnitude of acceleration of the stone?

Discussion

43.	A ball is hung vertically by a thread of length 'l' from a point of an inclined wall that makes an angle with the vertical. The thread with the ball is then deviated through a small angle α(α>β) and set free. Assuming the wall to be perfectly elastic, the period of such pendulum is
Answer» A ball is hung vertically by a thread of length 'l' from a point of an inclined wall that makes an angle with the vertical. The thread with the ball is then deviated through a small angle $α (α > β)$ and set free. Assuming the wall to be perfectly elastic, the period of such pendulum is

43.

A ball is hung vertically by a thread of length 'l' from a point of an inclined wall that makes an angle with the vertical. The thread with the ball is then deviated through a small angle α(α>β) and set free. Assuming the wall to be perfectly elastic, the period of such pendulum is

Answer»

A ball is hung vertically by a thread of length 'l' from a point of an inclined wall that makes an angle with the vertical. The thread with the ball is then deviated through a small angle $α (α > β)$ and set free. Assuming the wall to be perfectly elastic, the period of such pendulum is

Discussion

44.	A battery of internal resistance r having no load resistance has an e.m.f. E volt. What is the observed e.m.f across the terminals of the battery when a load resistance R(=r) is connected to its terminals?
Answer» A battery of internal resistance $r$ having no load resistance has an e.m.f. $E$ volt. What is the observed e.m.f across the terminals of the battery when a load resistance $R (= r)$ is connected to its terminals?

Discussion

45.	An electron in H-atom jumps from second excited state to first excited state and then from first excited to ground state. Let the ratio of wavelength, momentum and energy of photons emitted in these two cases be a, b and c respectively. Then
Answer» An electron in H-atom jumps from second excited state to first excited state and then from first excited to ground state. Let the ratio of wavelength, momentum and energy of photons emitted in these two cases be a, b and c respectively. Then

Discussion

46.	A body initially at rest is moving with uniform acceleration a. Its velocity after n seconds is v. The displacement of the body in last 2 s is:
Answer» A body initially at rest is moving with uniform acceleration $a$ . Its velocity after $n$ seconds is $v$ . The displacement of the body in last $2 s$ is:

Discussion

47.	Two stones are thrown up simultaneously from the edge of a cliff 240 m high with initial speed 10 m/s and 40 m/s respectively. Which of the following graph best represents the time variation of relative position of the second stone with respect to the first? (Assume stones do not rebound after hitting the ground and neglect air resistance, take g=10 m/s2) (The figures are schematic and not drawn to scale.)
Answer» Two stones are thrown up simultaneously from the edge of a cliff $240 m$ high with initial speed $10 m / s$ and $40 m / s$ respectively. Which of the following graph best represents the time variation of relative position of the second stone with respect to the first? (Assume stones do not rebound after hitting the ground and neglect air resistance, take $g = 10 m / s^{2}$ ) (The figures are schematic and not drawn to scale.)

Discussion

48.	The transfer ratio of a transistor is 50. The input resistance of the transistor when used in the common-emitter configuration is 1 kΩ. The peak value of the collector AC current for an AC input voltage of 0.01 V peak is (in μ m)
Answer» The transfer ratio of a transistor is 50. The input resistance of the transistor when used in the common-emitter configuration is 1 kΩ. The peak value of the collector AC current for an AC input voltage of 0.01 $V$ peak is (in $μ m$ )

Discussion

49.	A car is negotiating a curve of radius R = 20 m on a banked road with banking angle θ and coefficient of friction μ. Take speed of car as v. Column IColumn IIColumn III(I)v=10√2m/s(i)μ=0.2(P)θ=30∘(II)v=20m/s(ii)μ=0.4(Q)θ=45∘(III)v=50m/s(iii)μ=0.6(R)θ=37∘(IV)v=5m/s(iv)μ=0.8(S)θ=60∘ In which case will the friction be zero
Answer» A car is negotiating a curve of radius R = 20 m on a banked road with banking angle $θ$ and coefficient of friction $μ$ . Take speed of car as v. $\begin{matrix} Column I & Column II & Column III (I) & v = 10 \sqrt{2} m / s & (i) & μ = 0.2 & (P) & θ = 30^{\circ} (I I) & v = 20 m / s & (i i) & μ = 0.4 & (Q) & θ = 45^{\circ} (I I I) & v = 50 m / s & (i i i) & μ = 0.6 & (R) & θ = 37^{\circ} (I V) & v = 5 m / s & (i v) & μ = 0.8 & (S) & θ = 60^{\circ} \end{matrix}$ In which case will the friction be zero

49.

A car is negotiating a curve of radius R = 20 m on a banked road with banking angle θ and coefficient of friction μ. Take speed of car as v. Column IColumn IIColumn III(I)v=10√2m/s(i)μ=0.2(P)θ=30∘(II)v=20m/s(ii)μ=0.4(Q)θ=45∘(III)v=50m/s(iii)μ=0.6(R)θ=37∘(IV)v=5m/s(iv)μ=0.8(S)θ=60∘ In which case will the friction be zero

Answer»

A car is negotiating a curve of radius R = 20 m on a banked road with banking angle $θ$ and coefficient of friction $μ$ . Take speed of car as v.

$\begin{matrix} Column I & Column II & Column III (I) & v = 10 \sqrt{2} m / s & (i) & μ = 0.2 & (P) & θ = 30^{\circ} (I I) & v = 20 m / s & (i i) & μ = 0.4 & (Q) & θ = 45^{\circ} (I I I) & v = 50 m / s & (i i i) & μ = 0.6 & (R) & θ = 37^{\circ} (I V) & v = 5 m / s & (i v) & μ = 0.8 & (S) & θ = 60^{\circ} \end{matrix}$

In which case will the friction be zero

Discussion

50.	Two spheres of the same material and same radius ‘r’ are touching each other gravitational force between them is directly proportional to
Answer» Two spheres of the same material and same radius ‘r’ are touching each other gravitational force between them is directly proportional to

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Find the average velocity of a projective between the instands it crosses half the maximum height. It is projected with a speed u at angle θ with the horizontal.

A capacitore of capacitance 10 μ F is connected to an oscillator giving an output voltage ε = (10 V) sin ω t. Find the peak currents in the circuit for ω = 10 s−1, 100 s−1, 500 s−1, 1000 s−1

When will the relative velocity of two moving objects is zero?

A bus traveling the first one third distance at a speed of 10km/hr, next one fourth at 20km/hr and the remaining at 40km/hr. The average speed of the bus is nearly

A body is projected from the top of a tower of height 32 m with a velocity of 20 m/s at an angle of 37∘ above the horizontal. Find the horizontal distance travelled before it hits the ground. (Take g=10 m/s2)

The work function of sodium is 2.3 eV. The threshold wavelength of sodium will be

The maximum stress that can be applied to the material of a wire used to suspend an elevator is 108 Nm−2. If the mass of the elevator is 1000 kg and it moves up with an acceleration of 0.2 ms−2, what is the minimum diameter of the wire required? (Take g=9.8 m/s2)

A freei pitch ball of mass 6 gram carries a positive charge of (1/3 )* 10 ​​​​​​-7 coulomb what must be nature and magnitude of charge that should be given to second pitch ball fixed 5 cm vertically below the former baseball so that the upper bonus stationery.

The focal length of a double convex lens is equal to radius of curvature of either surface The refractive index of its material is

What is a pseudo force?

What is lines of force of magnet

Particle A makes a perfectly elastic collision with another particle B at rest. After collision, they fly apart in opposite directions with equal speeds. The ratio of masses mAmB is

What are straight lines ?

A body is thrown vertically upwards. If air resistance is to be taken into account, then the time during which the body rises is

An observer moves towards a stationary source of sound with a speed (1/5)th of the speed of sound. The wavelength and frequency of the source emitted are λ and f, respectively. The apparent frequency and wavelength recorded by the observer are, respectively,

What is dielectric constant

An aeroplane is moving in a circular path with a speed 250 km/h what is change in velocity in half revolution

Whatv is the reason to operate photodiodes in reverse bias?

A long spring is stretched by 2 cm, its potential energy is U. If the spring is stretched by 10 cm, the potential energy stored in it will be

A sphere of radius 1cm has potential of 8000V , then energy density near it's surface will be a) 6400000J/m3 b) 8000J/m3 c) 32J/m3 d) 2.83J/m3

What is the difference between the capacitance of a capacitor when they are connected in by a battery and disconnect from the battery

By what temperature a rod should be heated so that it's length becomes 2l0 if initial length is l0 . Assume that α (coefficient of linear expansion) in that range of temperature remains constant and melting point is very high.

The displacement x of a body moving in a straight line is related to time t as 2x2+3x=t. If v is the velocity of the body at a certain instant of time, its acceleration will be

Find the equivalent resistance of the network shown in figure (45-E8) between the points A and B.

Two parallel plane sheets 1 and 2 carry uniform charge densities σ1 and σ2 as in fig electric field in the region marked II is (σ1 &gt; σ2)

A simple pendulum of length 1 feet suspended from the ceiling of an elevator takes π3 seconds to complete one oscillation. Find the acceleration of the elevator.

A heavy particle is suspended by a string of length l. The particle is given a horizontal velocity v0. The string becomes slack at some angle and the particle proceeds on a parabola. Find the value of v0 if the particle passes through the point of suspension.

What is common for the given two blocks?

Hydrogen gas is filled in a balloon at 20∘C. If temperature is made 40∘C, pressure remaining same, what fraction of hydrogen will come out

A hollow sphere rolls without slipping on the horizontal surface such that its translational velocity is v. Find that the maximum height attained by it on an inclined surface as shown in the figure.

An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?

A particle is projected at an angle α with the horizontal from the foot of a plane, whose inclination to the horizontal is β. Find the velocity with which the particle strikes perpendicular to the inclined plane.

Derivative of f(x)=x2cosx is

The magnetic moment of a bar magnet is 1 joule per tesla. When bar magnet makes 300 with the field, we need a external torque of 3 Nm to hold it. Find the work required to turn it by further 900.

V verus T curves at constant pressures P1 and P2 for an idealgas are shown in the figure,

A cylindrical vessel filled with water is released on an inclined surface of inclination angle θ as shown in figure. The coefficient of friction between surface with vessel is μ(&lt;tan θ). Then the constant angle made by the surface of water with the incline will be

A stone tied to the end of a string 80 cm long is whirled in a horizontal circle with a constant speed. If the stone makes 14 revolutions in 25 seconds, what is the magnitude of acceleration of the stone?

A ball is hung vertically by a thread of length 'l' from a point of an inclined wall that makes an angle with the vertical. The thread with the ball is then deviated through a small angle α(α&gt;β) and set free. Assuming the wall to be perfectly elastic, the period of such pendulum is

A battery of internal resistance r having no load resistance has an e.m.f. E volt. What is the observed e.m.f across the terminals of the battery when a load resistance R(=r) is connected to its terminals?

An electron in H-atom jumps from second excited state to first excited state and then from first excited to ground state. Let the ratio of wavelength, momentum and energy of photons emitted in these two cases be a, b and c respectively. Then

A body initially at rest is moving with uniform acceleration a. Its velocity after n seconds is v. The displacement of the body in last 2 s is:

The transfer ratio of a transistor is 50. The input resistance of the transistor when used in the common-emitter configuration is 1 kΩ. The peak value of the collector AC current for an AC input voltage of 0.01 V peak is (in μ m)

Two spheres of the same material and same radius ‘r’ are touching each other gravitational force between them is directly proportional to

A freei pitch ball of mass 6 gram carries a positive charge of (1/3 )* 10 -7 coulomb what must be nature and magnitude of charge that should be given to second pitch ball fixed 5 cm vertically below the former baseball so that the upper bonus stationery.

Two parallel plane sheets 1 and 2 carry uniform charge densities σ1 and σ2 as in fig electric field in the region marked II is (σ1 > σ2)

A cylindrical vessel filled with water is released on an inclined surface of inclination angle θ as shown in figure. The coefficient of friction between surface with vessel is μ(<tan θ). Then the constant angle made by the surface of water with the incline will be

A ball is hung vertically by a thread of length 'l' from a point of an inclined wall that makes an angle with the vertical. The thread with the ball is then deviated through a small angle α(α>β) and set free. Assuming the wall to be perfectly elastic, the period of such pendulum is