50278 + Interview Questions in Physics

1.	A gas of density ρ flows with velocity v along a pipe of cross - sectional area S and bent to an angle of 90∘ at point A. What force does the gas exert on the pipe at point A ?
Answer» A gas of density $ρ$ flows with velocity $v$ along a pipe of cross - sectional area $S$ and bent to an angle of $90^{\circ}$ at point $A$ . What force does the gas exert on the pipe at point $A$ ?

Discussion

2.	A system of particle has rotational K.E. This system is isolated, but moment of inertia (I) may vary. Then the graph between K.E. and I is
Answer» A system of particle has rotational K.E. This system is isolated, but moment of inertia (I) may vary. Then the graph between K.E. and I is

Discussion

3.	End A of a rod AB is being pulled on the floor with a constant velocity v0 as shown. Taking the length of the rod as l, at an instant when the rod makes an angle 37∘ with the horizontal, calculate The velocity of end B
Answer» End $A$ of a rod $A B$ is being pulled on the floor with a constant velocity $v_{0}$ as shown. Taking the length of the rod as $l$ , at an instant when the rod makes an angle $37^{\circ}$ with the horizontal, calculate The velocity of end $B$

Discussion

4.	A bullet with muzzle velocity 100√2 m/s is to be fired at an angle of 45∘ with the horizontal. Find the coordinates of bullet after t=4 s, assuming bullet was initially at origin. Take g=10 m/s2.
Answer» A bullet with muzzle velocity $100 \sqrt{2} m/s$ is to be fired at an angle of $45^{\circ}$ with the horizontal. Find the coordinates of bullet after $t = 4 s$ , assuming bullet was initially at origin. Take $g = 10 {m/s}^{2}$ .

Discussion

5.	Position of a 10 kg block moving under influence of a force is given as s=6t3+5t2+10 (m), where t is in seconds. Find out the force acting after 10 sec.
Answer» Position of a $10 kg$ block moving under influence of a force is given as $s = 6 t^{3} + 5 t^{2} + 10 (m)$ , where $t$ is in seconds. Find out the force acting after $10 s e c$ .

Discussion

6.	A ball is projected vertically upward with a speed of 50 m/s. Find (a) The maximum height, (b) The time to reach the maximum beight, (c) The speed at half the maximum geight. take g = 10m/s2
Answer» A ball is projected vertically upward with a speed of 50 m/s. Find (a) The maximum height, (b) The time to reach the maximum beight, (c) The speed at half the maximum geight. take g = $10 m / s^{2}$

6.

A ball is projected vertically upward with a speed of 50 m/s. Find (a) The maximum height, (b) The time to reach the maximum beight, (c) The speed at half the maximum geight. take g = 10m/s2

Answer»

A ball is projected vertically upward with a speed of 50 m/s. Find

(a) The maximum height,

(b) The time to reach the maximum beight,

(c) The speed at half the maximum geight. take g = $10 m / s^{2}$

Discussion

7.	The resistance across the legs M and N of the letter A as shown in the following figure is :
Answer» The resistance across the legs M and N of the letter A as shown in the following figure is :

7.

The resistance across the legs M and N of the letter A as shown in the following figure is :

Answer»

The resistance across the legs M and N of the letter A as shown in the following figure is :

Discussion

8.	If the equation for the angular displacement of a particle moving on a circular path is given by θ=2t3+0.5, where θ is in radians and t in seconds, then the angular velocity of the particle at 2 s is
Answer» If the equation for the angular displacement of a particle moving on a circular path is given by $θ = 2 t^{3} + 0.5$ , where $θ$ is in radians and $t$ in seconds, then the angular velocity of the particle at $2 s$ is

Discussion

9.	How many kJ energy is spent when 1 ampere current is passed for 90 seconds under a potential of 100V?
Answer» How many kJ energy is spent when 1 ampere current is passed for 90 seconds under a potential of 100V?

Discussion

10.	Two narrow bores of diameters 3.0 mm and 6.0 mm are joined together to form a U-tube open at both ends. If the U-tube contains water, what is the difference in its levels in the two limbs of the tube? Surface tension of water at the temperature of the experiment is 7.3×10–2Nm–1. Take the angle of contact to be zero and density of water to be 1.0×103kgm–3(g=9.8ms–2).
Answer» Two narrow bores of diameters 3.0 mm and 6.0 mm are joined together to form a U-tube open at both ends. If the U-tube contains water, what is the difference in its levels in the two limbs of the tube? Surface tension of water at the temperature of the experiment is $7.3 \times 10^{- 2} N m^{- 1}$ . Take the angle of contact to be zero and density of water to be $1.0 \times 10^{3} k g m^{- 3} (g = 9.8 m s^{- 2})$ .

Discussion

11.	A uniform disc of radius 5.0 cm and mass 200 g is fixed at its centre to a metal rod, the other end of which is fixed to a celling. The hanging disc is rotated about the rod through an angle and is released. If the disc makes torsional oscillations with time period 0.20 s, find the torsional constant of the rod.
Answer» A uniform disc of radius $5.0 cm$ and mass $200 g$ is fixed at its centre to a metal rod, the other end of which is fixed to a celling. The hanging disc is rotated about the rod through an angle and is released. If the disc makes torsional oscillations with time period $0.20 s$ , find the torsional constant of the rod.

Discussion

12.	Which of the following is true regarding G as per the given seating arrangement?
Answer» Which of the following is true regarding G as per the given seating arrangement?

Discussion

13.	A particle of mass 0.3 kg is subjected to a force F=−kx with k=15Nm. What will be the magnitude of its initial acceleration (inms2) if it is released from a point x=20 cm from its equilibrium position?
Answer» A particle of mass 0.3 kg is subjected to a force $F = - k x$ with $k = 15 \frac{N}{m}$ . What will be the magnitude of its initial acceleration ( $i n \frac{m}{s^{2}}$ ) if it is released from a point x=20 cm from its equilibrium position?

Discussion

14.	The rate constant is numerically the same for three reaction of first, second and third order respectively. Which one is true for rate of three reaction, if concentration of reactant is greater than 1M? (1) r1 = r2 = r3 (2) r1 > r2 > r3 (3) r1 < r2 < r3 (4) All of these
Answer» The rate constant is numerically the same for three reaction of first, second and third order respectively. Which one is true for rate of three reaction, if concentration of reactant is greater than 1M? (1) r₁= r₂ = r₃ (2) r₁> r₂> r₃ (3) r₁< r₂< r₃ (4) All of these

14.

The rate constant is numerically the same for three reaction of first, second and third order respectively. Which one is true for rate of three reaction, if concentration of reactant is greater than 1M? (1) r1 = r2 = r3 (2) r1 > r2 > r3 (3) r1 < r2 < r3 (4) All of these

Answer»

The rate constant is numerically the same for three reaction of first, second and third order respectively. Which one is true for rate of three reaction, if concentration of reactant is greater than 1M?

(1) r₁= r₂ = r₃

(2) r₁> r₂> r₃

(3) r₁< r₂< r₃

(4) All of these

Discussion

15.	A tuning fork T produces 4 beats per second with a source ′S′. On loading wax on T, it gives 5 beats per second with the same source. When the source ′S′ moves towards a fixed wall with a speed 5 m/s then again T gives 5 beats per second with echo of the source. If speed of sound is 340 m/s, then frequency of the tuning fork, before loading wax, is
Answer» A tuning fork $T$ produces 4 beats per second with a source $^{'} S^{'}$ . On loading wax on $T$ , it gives $5$ beats per second with the same source. When the source $^{'} S^{'}$ moves towards a fixed wall with a speed $5 m/s$ then again $T$ gives $5$ beats per second with echo of the source. If speed of sound is $340 m/s$ , then frequency of the tuning fork, before loading wax, is

Discussion

16.	Five uniform circular plates, each of diameter b and mass m, are placed together to form a pattern as shown in the figure. Find the y coordinate of the centre of mass of the system.
Answer» Five uniform circular plates, each of diameter $b$ and mass $m$ , are placed together to form a pattern as shown in the figure. Find the $y$ coordinate of the centre of mass of the system.

Discussion

17.	A force →F=[y^i+x^j]N acts on a particle moving in x−y plane starting from the point (3,5)m, the particle is taken along a straight line to (5,7)m. The work done by the force( in J upto two decimals) is:
Answer» A force $\to F = [y^i + x^j] N$ acts on a particle moving in $x - y$ plane starting from the point $(3, 5) m$ , the particle is taken along a straight line to $(5, 7) m$ . The work done by the force( in $J$ upto two decimals) is:

Discussion

18.	a body whose mass is 6 kg is acted on by a force which changes its velocity from 3 M per second to 5 M per second find the Impulse of Force.if force is active for 2 seconds find the force in Newtons .
Answer» a body whose mass is 6 kg is acted on by a force which changes its velocity from 3 M per second to 5 M per second find the Impulse of Force.if force is active for 2 seconds find the force in Newtons .

Discussion

19.	At what height above the earth’s surface the acceleration due to gravity will be 1/9th of its value at the earth’s surface ?
Answer» At what height above the earth’s surface the acceleration due to gravity will be 1/9th of its value at the earth’s surface ?

Discussion

20.	The magnitude of average velocity is equal to the average speed if the motion of an object is along a straight line and in the same direction.
Answer» The magnitude of average velocity is equal to the average speed if the motion of an object is along a straight line and in the same direction.

Discussion

21.	A bomb is projected with initial velocity 9.8 m/s making 15∘ angle with the horizontal. Bomb explodes into two parts in the mass ratio 1 : 2 at the point where vertical component of velocity is zero. If the heavier mass falls vertically down, how far on the ground from projection point will the lighter mass fall?
Answer» A bomb is projected with initial velocity $9.8 m/s$ making $15^{\circ}$ angle with the horizontal. Bomb explodes into two parts in the mass ratio 1 : 2 at the point where vertical component of velocity is zero. If the heavier mass falls vertically down, how far on the ground from projection point will the lighter mass fall?

Discussion

22.	A rod of length l made of material of thermal conductivity k can transfer a given amount of heat in 12 seconds. If the length of the rod is doubled keeping the volume constant, it is noted that rod can transfer same heat in t seconds. Find the value of ′t′.
Answer» A rod of length $l$ made of material of thermal conductivity $k$ can transfer a given amount of heat in $12 seconds$ . If the length of the rod is doubled keeping the volume constant, it is noted that rod can transfer same heat in $t seconds$ . Find the value of $^{'} t^{'}$ .

Discussion

23.	Tell me distance which is not equal to zero if a man is falling with initial velocity zero and his final velociy as zero so that he does getsany hurt And is it possible that if a man can have his final velocity as zero(suppose) that he will definitely don't gets any hurt
Answer» Tell me distance which is not equal to zero if a man is falling with initial velocity zero and his final velociy as zero so that he does getsany hurt And is it possible that if a man can have his final velocity as zero(suppose) that he will definitely don't gets any hurt

23.

Tell me distance which is not equal to zero if a man is falling with initial velocity zero and his final velociy as zero so that he does getsany hurt And is it possible that if a man can have his final velocity as zero(suppose) that he will definitely don't gets any hurt

Answer»

Tell me distance which is not equal to zero if a man is falling with initial velocity zero and his final velociy as zero so that he does getsany hurt

And is it possible that if a man can have his final velocity as zero(suppose) that he will definitely don't gets any hurt

Discussion

24.	In the relation Kinetic Energy = p²/2m (where p is momentum, m is mass ) . If Momentum is raised by 0.1 % what will be the percentage increase in Kinetic Energy
Answer» In the relation Kinetic Energy = p²/2m (where p is momentum, m is mass ) . If Momentum is raised by 0.1 % what will be the percentage increase in Kinetic Energy

Discussion

25.	Point charges +4q, -q and +4q are kept on the X-axis at points x=0,x=a and x=2a respectively. Are all the charges stable or unstable?
Answer» Point charges +4q, -q and +4q are kept on the X-axis at points x=0,x=a and x=2a respectively. Are all the charges stable or unstable?

Discussion

26.	An object of mass m moves in a circular path of radius R under the action of a force of constant magnitude F. The kinetic energy of object is?
Answer» An object of mass m moves in a circular path of radius R under the action of a force of constant magnitude F. The kinetic energy of object is?

Discussion

27.	In a coolidge tube, the potential difference used to accelerate the electrons is increased from 12.4 kV to 24.8 kV. As a result, the difference between the wavelength of Kα -line and minimum wavelength increases two-fold. The wavelength (in Å) of the Kα line is (hce=12.4 kVA)
Answer» In a coolidge tube, the potential difference used to accelerate the electrons is increased from $12.4 kV$ to $24.8 kV$ . As a result, the difference between the wavelength of $K_{α}$ -line and minimum wavelength increases two-fold. The wavelength (in $Å$ ) of the $K_{α}$ line is $(\frac{h c}{e} = 12.4 kVA)$

Discussion

28.	A hemi-spherical bowl of radius R=0.1 m is rotating about its own axis (vertical) with uniform angular speed ′ω′. A particle of mass 10−2 kg is placed on the inner surface (smooth) of the bowl at a height h′ from the bottom of bowl. What is the minimum value of ′ω′ to have a non-zero value of ′h′, for which the particle remains at rest? (Take g=10 m/s2)
Answer» A hemi-spherical bowl of radius $R = 0.1 m$ is rotating about its own axis (vertical) with uniform angular speed $^{'} ω^{'}$ . A particle of mass $10^{- 2} kg$ is placed on the inner surface (smooth) of the bowl at a height $h^{'}$ from the bottom of bowl. What is the minimum value of $^{'} ω^{'}$ to have a non-zero value of $^{'} h^{'}$ , for which the particle remains at rest? (Take $g = 10 {m/s}^{2}$ )

Discussion

29.	A body can be negatively charged by
Answer» A body can be negatively charged by

29.

A body can be negatively charged by

Answer»

A body can be negatively charged by

Discussion

30.	The speed of the yellow light in a certain liquid is 2.4×108 m.s−1 Find the refractive index of the liquid.
Answer» The speed of the yellow light in a certain liquid is $2.4 \times 10^{8}$ m. $s^{- 1}$ Find the refractive index of the liquid.

Discussion

31.	By what distance do the wedges move if horizontal plank moves by x cm downwards?
Answer» By what distance do the wedges move if horizontal plank moves by $x cm$ downwards?

Discussion

32.	In the figure shown, a force of 10 N is applied to the 2 Kg mass at t=0 s. All surfaces are smooth and ignore the size of body B. Find the time after which the body B will lose contact with the plank A of length 10 m.
Answer» In the figure shown, a force of $10 N$ is applied to the $2 K g$ mass at $t = 0 s$ . All surfaces are smooth and ignore the size of body $B$ . Find the time after which the body $B$ will lose contact with the plank $A$ of length $10 m$ .

Discussion

33.	A skier plans to ski a smooth fixed hemisphere of radius R. He starts from rest from a curved smooth surface of height (R/4). The angle θ at which he leaves the hemisphere is
Answer» A skier plans to ski a smooth fixed hemisphere of radius R. He starts from rest from a curved smooth surface of height (R/4). The angle $θ$ at which he leaves the hemisphere is

Discussion

34.	In the circuit shown in figure, the power which is dissipated as heat in the 6Ω resistor is 6 W. What is the value of resistance R in the circuit?
Answer» In the circuit shown in figure, the power which is dissipated as heat in the $6 Ω$ resistor is $6 W$ . What is the value of resistance $R$ in the circuit?

Discussion

35.	On an inclined plane, two blocks are moving with constant velocities as shown in figure. Neglect the effect of gravity. Find the velocity of their COM.
Answer» On an inclined plane, two blocks are moving with constant velocities as shown in figure. Neglect the effect of gravity. Find the velocity of their $C O M$ .

Discussion

36.	A system of a circular disc of mass 900 g and radius 4 m and a circular ring of mass 2 kg and radius 5 m are stacked about their common centre as shown in figure. What is the moment of inertia of the system about an axis passing through their common centre perpendicular to the plane of the disc and the ring?
Answer» A system of a circular disc of mass $900 g$ and radius $4 m$ and a circular ring of mass $2 kg$ and radius $5 m$ are stacked about their common centre as shown in figure. What is the moment of inertia of the system about an axis passing through their common centre perpendicular to the plane of the disc and the ring?

Discussion

37.	A motorboat going downstream overcome a raft at a point A at T= 60 min later it turned back and after some time passed the raft at a distance l = 6 km from the point A. Find the flow velocity assuming the duty of engine to be constant
Answer» A motorboat going downstream overcome a raft at a point A at T= 60 min later it turned back and after some time passed the raft at a distance l = 6 km from the point A. Find the flow velocity assuming the duty of engine to be constant

Discussion

38.	If the lines are drawn in proportion to the charge, what is the ratio q1q2?
Answer» If the lines are drawn in proportion to the charge, what is the ratio $\frac{q_{1}}{q_{2}}$ ?

38.

If the lines are drawn in proportion to the charge, what is the ratio q1q2?

Answer»

If the lines are drawn in proportion to the charge, what is the ratio $\frac{q_{1}}{q_{2}}$ ?

Discussion

39.	What is the minimum length of a plane mirror required for a person to see his or her full image?
Answer» What is the minimum length of a plane mirror required for a person to see his or her full image?

Discussion

40.	If during an adiabatic process, the pressure of a gas is found to be proportional to the square root of the 5th power of its absolute temperature, the ratio Cp/Cv for the gas is
Answer» If during an adiabatic process, the pressure of a gas is found to be proportional to the square root of the $5^{th}$ power of its absolute temperature, the ratio $C_{p} / C_{v}$ for the gas is

Discussion

41.	A uniform rod of mass M and length 2 m lies on a smooth horizontal table. A particle of mass m moving on the table with a velocity u strikes the rod perpendicularly at an end and stops there. Find the distance travelled by the center of the rod (in metres) by the time it turns through a right angle. Given M=4m.
Answer» A uniform rod of mass $M$ and length $2 m$ lies on a smooth horizontal table. A particle of mass $m$ moving on the table with a velocity $u$ strikes the rod perpendicularly at an end and stops there. Find the distance travelled by the center of the rod (in metres) by the time it turns through a right angle. Given $M = 4 m$ .

Discussion

42.	The rear side of a truck is open and a box of mass 20 kg is placed on the truck 4 m away from the open end, μ=0.15 and g=10 m/sec2. The truck starts from rest with an acceleration of 2 m/sec2 on a straight road. The distance moved by the truck when box starts fall down.
Answer» The rear side of a truck is open and a box of mass $20 kg$ is placed on the truck $4 m$ away from the open end, $μ = 0.15$ and $g = 10 {m/sec}^{2}$ . The truck starts from rest with an acceleration of $2 {m/sec}^{2}$ on a straight road. The distance moved by the truck when box starts fall down.

Discussion

43.	The terminal speed of a sphere of gold (density = 19.5 g/cm3) is 0.2 m/s in a viscous liquid (density = 1.5 g/cm3). Find the terminal speed of a sphere of silver (density =10.5 g/cm3) of the same size in the same liquid (in m/s)
Answer» The terminal speed of a sphere of gold (density = $19.5 {g/cm}^{3})$ is $0.2 m/s$ in a viscous liquid (density = $1.5 {g/cm}^{3}$ ). Find the terminal speed of a sphere of silver (density $= 10.5 {g/cm}^{3})$ of the same size in the same liquid (in $m/s$ )

Discussion

44.	A chain of 125 links is 1.25 m long and has a mass of 2 kg. With the ends fastened together, it is set rotating at 3000 rpm. The centripetal force(in N) on each link is( consider π=3.14)
Answer» A chain of $125$ links is $1.25 m$ long and has a mass of $2 kg$ . With the ends fastened together, it is set rotating at $3000 rpm$ . The centripetal force(in $N$ ) on each link is( consider $π = 3.14$ )

Discussion

45.	The resistance of a galvanometer is 10 Ω. It gives full-scale deflection when 1 mA current is passed. The resistance connected in series for converting it into a voltmeter of 2.5 V will be
Answer» The resistance of a galvanometer is $10 Ω$ . It gives full-scale deflection when $1 m A$ current is passed. The resistance connected in series for converting it into a voltmeter of $2.5 V$ will be

Discussion

46.	What is the difference between the u and v while solving numericals
Answer» What is the difference between the u and v while solving numericals

Discussion

47.	A circular disc of radius ′R′ and mass ′m′ is hinged at the centre about horizontal axis. A particle of same mass is attached at the top of the disc. Now the system is released. Calculate the angular velocity of the disc when the particle reaches bottom.
Answer» A circular disc of radius $^{'} R^{'}$ and mass $^{'} m^{'}$ is hinged at the centre about horizontal axis. A particle of same mass is attached at the top of the disc. Now the system is released. Calculate the angular velocity of the disc when the particle reaches bottom.

Discussion

48.	Under the action of force, a 2 kg body moves such that x is a function of time given by x=t3/3, x in metre, t in seconds, find the work done in first two seconds.
Answer» Under the action of force, a 2 kg body moves such that x is a function of time given by $x = t^{3} / 3$ , x in metre, t in seconds, find the work done in first two seconds.

Discussion

49.	A liquid is under streamline flow through a horizontal pipe of non uniform cross-sectional area. If the volume rate of flow at a cross-section of area a is V, then volume rate of flow at a different cross-section of area a2 is
Answer» A liquid is under streamline flow through a horizontal pipe of non uniform cross-sectional area. If the volume rate of flow at a cross-section of area $a$ is $V$ , then volume rate of flow at a different cross-section of area $\frac{a}{2}$ is

Discussion

50.	Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively, successively illuminates a metal of work function 0.5 eV. The ratio of maximum kinetic energy of the emitted electron will be
Answer» Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively, successively illuminates a metal of work function 0.5 eV. The ratio of maximum kinetic energy of the emitted electron will be

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A gas of density ρ flows with velocity v along a pipe of cross - sectional area S and bent to an angle of 90∘ at point A. What force does the gas exert on the pipe at point A ?

A system of particle has rotational K.E. This system is isolated, but moment of inertia (I) may vary. Then the graph between K.E. and I is

End A of a rod AB is being pulled on the floor with a constant velocity v0 as shown. Taking the length of the rod as l, at an instant when the rod makes an angle 37∘ with the horizontal, calculate The velocity of end B

A bullet with muzzle velocity 100√2 m/s is to be fired at an angle of 45∘ with the horizontal. Find the coordinates of bullet after t=4 s, assuming bullet was initially at origin. Take g=10 m/s2.

Position of a 10 kg block moving under influence of a force is given as s=6t3+5t2+10 (m), where t is in seconds. Find out the force acting after 10 sec.

A ball is projected vertically upward with a speed of 50 m/s. Find (a) The maximum height, (b) The time to reach the maximum beight, (c) The speed at half the maximum geight. take g = 10m/s2

The resistance across the legs M and N of the letter A as shown in the following figure is :

If the equation for the angular displacement of a particle moving on a circular path is given by θ=2t3+0.5, where θ is in radians and t in seconds, then the angular velocity of the particle at 2 s is

How many kJ energy is spent when 1 ampere current is passed for 90 seconds under a potential of 100V?

Which of the following is true regarding G as per the given seating arrangement?

A particle of mass 0.3 kg is subjected to a force F=−kx with k=15Nm. What will be the magnitude of its initial acceleration (inms2) if it is released from a point x=20 cm from its equilibrium position?

The rate constant is numerically the same for three reaction of first, second and third order respectively. Which one is true for rate of three reaction, if concentration of reactant is greater than 1M? (1) r1 = r2 = r3 (2) r1 &gt; r2 &gt; r3 (3) r1 &lt; r2 &lt; r3 (4) All of these

Five uniform circular plates, each of diameter b and mass m, are placed together to form a pattern as shown in the figure. Find the y coordinate of the centre of mass of the system.

A force →F=[y^i+x^j]N acts on a particle moving in x−y plane starting from the point (3,5)m, the particle is taken along a straight line to (5,7)m. The work done by the force( in J upto two decimals) is:

a body whose mass is 6 kg is acted on by a force which changes its velocity from 3 M per second to 5 M per second find the Impulse of Force.if force is active for 2 seconds find the force in Newtons .

At what height above the earth’s surface the acceleration due to gravity will be 1/9th of its value at the earth’s surface ?

The magnitude of average velocity is equal to the average speed if the motion of an object is along a straight line and in the same direction.

A rod of length l made of material of thermal conductivity k can transfer a given amount of heat in 12 seconds. If the length of the rod is doubled keeping the volume constant, it is noted that rod can transfer same heat in t seconds. Find the value of ′t′.

Tell me distance which is not equal to zero if a man is falling with initial velocity zero and his final velociy as zero so that he does getsany hurt And is it possible that if a man can have his final velocity as zero(suppose) that he will definitely don't gets any hurt

In the relation Kinetic Energy = p²/2m (where p is momentum, m is mass ) . If Momentum is raised by 0.1 % what will be the percentage increase in Kinetic Energy

Point charges +4q, -q and +4q are kept on the X-axis at points x=0,x=a and x=2a respectively. Are all the charges stable or unstable?

An object of mass m moves in a circular path of radius R under the action of a force of constant magnitude F. The kinetic energy of object is?

In a coolidge tube, the potential difference used to accelerate the electrons is increased from 12.4 kV to 24.8 kV. As a result, the difference between the wavelength of Kα -line and minimum wavelength increases two-fold. The wavelength (in Å) of the Kα line is (hce=12.4 kVA)

A body can be negatively charged by

The speed of the yellow light in a certain liquid is 2.4×108 m.s−1 Find the refractive index of the liquid.

By what distance do the wedges move if horizontal plank moves by x cm downwards?

In the figure shown, a force of 10 N is applied to the 2 Kg mass at t=0 s. All surfaces are smooth and ignore the size of body B. Find the time after which the body B will lose contact with the plank A of length 10 m.

A skier plans to ski a smooth fixed hemisphere of radius R. He starts from rest from a curved smooth surface of height (R/4). The angle θ at which he leaves the hemisphere is

In the circuit shown in figure, the power which is dissipated as heat in the 6Ω resistor is 6 W. What is the value of resistance R in the circuit?

On an inclined plane, two blocks are moving with constant velocities as shown in figure. Neglect the effect of gravity. Find the velocity of their COM.

A motorboat going downstream overcome a raft at a point A at T= 60 min later it turned back and after some time passed the raft at a distance l = 6 km from the point A. Find the flow velocity assuming the duty of engine to be constant

If the lines are drawn in proportion to the charge, what is the ratio q1q2?

What is the minimum length of a plane mirror required for a person to see his or her full image?

If during an adiabatic process, the pressure of a gas is found to be proportional to the square root of the 5th power of its absolute temperature, the ratio Cp/Cv for the gas is

The rear side of a truck is open and a box of mass 20 kg is placed on the truck 4 m away from the open end, μ=0.15 and g=10 m/sec2. The truck starts from rest with an acceleration of 2 m/sec2 on a straight road. The distance moved by the truck when box starts fall down.

The terminal speed of a sphere of gold (density = 19.5 g/cm3) is 0.2 m/s in a viscous liquid (density = 1.5 g/cm3). Find the terminal speed of a sphere of silver (density =10.5 g/cm3) of the same size in the same liquid (in m/s)

A chain of 125 links is 1.25 m long and has a mass of 2 kg. With the ends fastened together, it is set rotating at 3000 rpm. The centripetal force(in N) on each link is( consider π=3.14)

The resistance of a galvanometer is 10 Ω. It gives full-scale deflection when 1 mA current is passed. The resistance connected in series for converting it into a voltmeter of 2.5 V will be

What is the difference between the u and v while solving numericals

A circular disc of radius ′R′ and mass ′m′ is hinged at the centre about horizontal axis. A particle of same mass is attached at the top of the disc. Now the system is released. Calculate the angular velocity of the disc when the particle reaches bottom.

Under the action of force, a 2 kg body moves such that x is a function of time given by x=t3/3, x in metre, t in seconds, find the work done in first two seconds.

A liquid is under streamline flow through a horizontal pipe of non uniform cross-sectional area. If the volume rate of flow at a cross-section of area a is V, then volume rate of flow at a different cross-section of area a2 is

Light of two different frequencies whose photons have energies 1 eV and 2.5 eV respectively, successively illuminates a metal of work function 0.5 eV. The ratio of maximum kinetic energy of the emitted electron will be

The rate constant is numerically the same for three reaction of first, second and third order respectively. Which one is true for rate of three reaction, if concentration of reactant is greater than 1M? (1) r1 = r2 = r3 (2) r1 > r2 > r3 (3) r1 < r2 < r3 (4) All of these