50278 + Interview Questions in Physics

1.	The net force on a body is varying with time as (2t + 3) N. Find the change in momentum of the body after 2 secs?
Answer» The net force on a body is varying with time as (2t + 3) N. Find the change in momentum of the body after 2 secs?

Discussion

2.	Two blocks of mass m1=4 kg and m2=2 kg, connected by a weightless rod on a plane having inclination of 37∘ is shown in figure. If the coefficient of dynamic friction is μ=0.25, then the common acceleration of the two blocks and the tension (T) in the rod are
Answer» Two blocks of mass $m_{1} = 4 kg$ and $m_{2} = 2 kg$ , connected by a weightless rod on a plane having inclination of $37^{\circ}$ is shown in figure. If the coefficient of dynamic friction is $μ = 0.25$ , then the common acceleration of the two blocks and the tension $(T)$ in the rod are

Discussion

3.	The speed of a transverse wave travelling through a wire having a length 50 cm and mass 5.0 g is 80 m/s. The area of cross-section of the wire is 1.0 mm2 and its Young's modulus is 16×1011 N/m2. Find the extension in the wire with respect to its natural length.
Answer» The speed of a transverse wave travelling through a wire having a length $50 cm$ and mass $5.0 g$ is $80 m/s$ . The area of cross-section of the wire is $1.0 {mm}^{2}$ and its Young's modulus is $16 \times 10^{11} {N/m}^{2}$ . Find the extension in the wire with respect to its natural length.

Discussion

4.	An ideal monoatomic gas is confined in a cylinder by a spring loaded piston of cross sectional area 4×10−3m2. Initially the gas is at 27∘C and volume of gas is 1.2×10−3m3, system is in equilibrium and spring is in natural state. The sample is heated by a heater until piston moves out slowly by 5 cm. Calculate final temperature of the gas and heat supplied by heater. Take k (spring constant) = 8000 N/m, mass of piston = 20 kg (Assume there is no loss of heat through coils and walls, take Patm=105Pa ) Final temperature of the gas (in K): Heat supplied by heater (in J):
Answer» An ideal monoatomic gas is confined in a cylinder by a spring loaded piston of cross sectional area $4 \times 10^{- 3} m^{2}$ . Initially the gas is at $27^{\circ} C$ and volume of gas is $1.2 \times 10^{- 3} m^{3}$ , system is in equilibrium and spring is in natural state. The sample is heated by a heater until piston moves out slowly by $5 cm$ . Calculate final temperature of the gas and heat supplied by heater. Take $k$ (spring constant) = $8000 N / m$ , mass of piston = $20 kg$ (Assume there is no loss of heat through coils and walls, take $P_{a} t m = 10^{5} Pa$ ) Final temperature of the gas (in $K$ ): Heat supplied by heater (in $J$ ):

Discussion

5.	Which of the following options are correct regarding the molar heat capacity (C) for the gas whose PV graph is shown below.
Answer» Which of the following options are correct regarding the molar heat capacity $(C)$ for the gas whose $P V$ graph is shown below.

Discussion

6.	What is the magnitude of →v ?
Answer» What is the magnitude of $\to v$ ?

Discussion

7.	In the figure shown, find the tension in the string connecting the blocks of mass 2 kg and 3 kg. Take g=10 m/s2
Answer» In the figure shown, find the tension in the string connecting the blocks of mass $2 k g$ and $3 k g$ . Take $g = 10 m / s^{2}$

Discussion

8.	In the equation representing wave function, y=Asin(kx−ωt+ϕ0) The term phase is defined as:
Answer» In the equation representing wave function, $y = A sin (k x - ω t + ϕ_{0})$ The term phase is defined as:

Discussion

9.	The average time of motion of electrons between two successive collisions with fixed positive ions inside a conductor is called the ___ time
Answer» The average time of motion of electrons between two successive collisions with fixed positive ions inside a conductor is called the ___ time

Discussion

10.	A particle of mass m moves with constant speed v on a circular path of radius r. Find the magnitude of average force on it in half revolution.
Answer» A particle of mass m moves with constant speed v on a circular path of radius r. Find the magnitude of average force on it in half revolution.

Discussion

11.	The area of cross-section, length, and density of a piece of a metal of atomic weight 60 are 10-6 m2, 1.0 m and 5 x 103 kgm-3 respectively. The number of free electrons per unit volume if every atom contributes one free electron is
Answer» The area of cross-section, length, and density of a piece of a metal of atomic weight 60 are 10^-6 m², 1.0 m and 5 x 10³ kgm^-3 respectively. The number of free electrons per unit volume if every atom contributes one free electron is

Discussion

12.	When a bomb is thrown from an aeroplane(uniform motion), what is the initial velocity of throwing ball.
Answer» When a bomb is thrown from an aeroplane(uniform motion), what is the initial velocity of throwing ball.

Discussion

13.	Two very long straight parallel wires 1 and 2 are separated by a small distance and carry the same current I. The current in wire 1 flows out of the page and that in wire 2 flows into the page. What is the direction of the magnetic field at point P due to the current in the wires? Point P is equidistant from the wires as shown in the figure below.
Answer» Two very long straight parallel wires 1 and 2 are separated by a small distance and carry the same current I. The current in wire 1 flows out of the page and that in wire 2 flows into the page. What is the direction of the magnetic field at point P due to the current in the wires? Point P is equidistant from the wires as shown in the figure below.

Discussion

14.	A string of length l along x− axis is fixed at both ends and is vibrating in second harmonic. If amplitude of incident wave is 2.5 mm, the equation of standing wave is (T is tension and μ is linear density)
Answer» A string of length $l$ along $x -$ axis is fixed at both ends and is vibrating in second harmonic. If amplitude of incident wave is $2.5 mm$ , the equation of standing wave is (T is tension and $μ$ is linear density)

Discussion

15.	electric charges are spread to volume the flux of electric field trough a spherical surface of radius 10cm sourrounding the charge 20Vm the flux over a cocentric sphere of radius 20cm will be
Answer» electric charges are spread to volume the flux of electric field trough a spherical surface of radius 10cm sourrounding the charge 20Vm the flux over a cocentric sphere of radius 20cm will be

Discussion

16.	The density of a linear rod of length 'L' varies as p = A+Bx where x is the distance from the left end. Then the position of the centre of mass from the left end is
Answer» The density of a linear rod of length 'L' varies as p = A+Bx where x is the distance from the left end. Then the position of the centre of mass from the left end is

Discussion

17.	A rectangular lamina ABCD has same density along side AD but has increasing density along side AB. The density along side AB is given as ρ=ρ0+kx where ρ0 and k are constants and x is distance from the side AD. Find the distance of COM from side AD.
Answer» A rectangular lamina $A B C D$ has same density along side $A D$ but has increasing density along side $A B$ . The density along side $A B$ is given as $ρ = ρ_{0} + k x$ where $ρ_{0}$ and $k$ are constants and $x$ is distance from the side $A D$ . Find the distance of $C O M$ from side $A D$ .

Discussion

18.	A uniform electric field is given by, E=−180^kV/m (a) What is the change in potential from zA=5cm to zB=15 cm? (b) How far apart along the z-axis are two points that differ in potential by 27 V?
Answer» A uniform electric field is given by, $E = - 180^k V / m$ (a) What is the change in potential from $z_{A} = 5 c m t o z_{B} = 15 c m$ ? (b) How far apart along the z-axis are two points that differ in potential by 27 V?

Discussion

19.	It is given that complex numbers z1 and z2 satisfy \|z1\| = 2 and \|z2\| = 3. If the included angle of their corresponding vectors is 60o the ∣∣z1+z2z1−z2∣∣ can be expressed as √x7 where `x` is a natural number the `x` equals to.
Answer» It is given that complex numbers $z_{1}$ and $z_{2}$ satisfy $\| z_{1} \|$ = 2 and $\| z_{2} \|$ = 3. If the included angle of their corresponding vectors is $60^{o}$ the $∣ ∣ \frac{z_{1} + z_{2}}{z_{1} - z_{2}} ∣ ∣$ can be expressed as $\frac{\sqrt{x}}{7}$ where `x` is a natural number the `x` equals to.

Discussion

20.	A material having on index of reflection μ is surrounded by vaccum and is in the shape of a quarter circle of radius R. A light ray parallel to the base of the material is incident from the left at a distance of L above the base and emerges out of the material at an angle θ. Determine on expression of θ.
Answer» A material having on index of reflection $μ$ is surrounded by vaccum and is in the shape of a quarter circle of radius R. A light ray parallel to the base of the material is incident from the left at a distance of L above the base and emerges out of the material at an angle $θ$ . Determine on expression of $θ$ .

Discussion

21.	A man running on a circular track of radius=20 m, Find the linear distance travelled by the man when he completes 5 revolutions?
Answer» A man running on a circular track of radius $= 20 m$ , Find the linear distance travelled by the man when he completes $5$ revolutions?

Discussion

22.	If i jump of the building i will get hurt but while cats they jump of from fourth floor but still they do not get hurt.why?
Answer» If i jump of the building i will get hurt but while cats they jump of from fourth floor but still they do not get hurt.why?

Discussion

23.	When two bodies move uniformly towards each other, the distance between them diminishes by 16 m every 10 s. If bodies move in same direction with velocities of the same magnitude as before, the distance between them will decrease by 3 m in every 5 s. The velocity of each body is
Answer» When two bodies move uniformly towards each other, the distance between them diminishes by $16 m$ every $10 s$ . If bodies move in same direction with velocities of the same magnitude as before, the distance between them will decrease by $3 m$ in every $5 s$ . The velocity of each body is

Discussion

24.	A body of mass 2 kg is kept on a rough horizontal surface. If μs=0.5 and an external force of F=5 N is applied on the body, find the angle of friction. (Take g=10 m/s2)
Answer» A body of mass $2 kg$ is kept on a rough horizontal surface. If $μ_{s} = 0.5$ and an external force of $F = 5 N$ is applied on the body, find the angle of friction. (Take $g = 10 {m/s}^{2}$ )

Discussion

25.	The work function of a metal is 4.2 eV, its threshold wavelength will be
Answer» The work function of a metal is 4.2 eV, its threshold wavelength will be

Discussion

26.	Three rods made of the same material and having the same cross-section,same length have been joined as shown in the ﬁgure. The extreme left and right ends are kept at 0∘C and 90∘C respectively. The temperature of the junction of the three rods will be
Answer» Three rods made of the same material and having the same cross-section,same length have been joined as shown in the ﬁgure. The extreme left and right ends are kept at $0^{\circ} C$ and $90^{\circ} C$ respectively. The temperature of the junction of the three rods will be

Discussion

27.	Which of the curves in figure represents the relation between Celsius and Fahrenheit temperatures?
Answer» Which of the curves in figure represents the relation between Celsius and Fahrenheit temperatures?

Discussion

28.	What are the advantages of using AC over DC?
Answer» What are the advantages of using AC over DC?

Discussion

29.	It is known that wax contracts on solidification. If molten wax is taken in a large vessel and it is allowed to cool slowly, then
Answer» It is known that wax contracts on solidification. If molten wax is taken in a large vessel and it is allowed to cool slowly, then

Discussion

30.	A metre scale made of steel is calibrated at 20∘C to give correct reading. Find the distance between 50 cm mark and 51 cm mark if the scale is used at 10∘C. Coefficient of linear expansion of steel is 1.1×10−5 ∘C−1
Answer» A metre scale made of steel is calibrated at $20^{\circ} C$ to give correct reading. Find the distance between 50 cm mark and 51 cm mark if the scale is used at $10^{\circ} C$ . Coefficient of linear expansion of steel is $1.1 \times 10^{- 5}^{\circ} C^{- 1}$

Discussion

31.	A,B and C are voltmeters of resistance R,1.5R and 3R respectively. When some potential difference is applied between X and Y, the voltmeter readings are VA,VB and VC respectively. Then
Answer» $A, B$ and $C$ are voltmeters of resistance $R, 1.5 R$ and $3 R$ respectively. When some potential difference is applied between $X$ and $Y$ , the voltmeter readings are $V_{A}, V_{B}$ and $V_{C}$ respectively. Then

Discussion

32.	If a man increases his speed by 2 m/s, his kinetic energy is doubled. The original speed of the man is
Answer» If a man increases his speed by $2 m / s$ , his kinetic energy is doubled. The original speed of the man is

Discussion

33.	A metal sphere of radius 1 mm and mass 50 mg falls verticcally in glycerine. Find (a) the viscous force exerted by the glycerine on the sphere when the speed of the sphere is 1 cm s^{-1}, (b) the hydrostatic force exerted by the glycerine on the sphere and (c) the terminal velocity with which the sphere will move down without acceleration. Density of glycerine = 1260kgm−3 and its coefficient of viscosity at room temperature = 8.0 poise.
Answer» A metal sphere of radius 1 mm and mass 50 mg falls verticcally in glycerine. Find (a) the viscous force exerted by the glycerine on the sphere when the speed of the sphere is 1 cm s^{-1}, (b) the hydrostatic force exerted by the glycerine on the sphere and (c) the terminal velocity with which the sphere will move down without acceleration. Density of glycerine = $1260 k g m^{- 3}$ and its coefficient of viscosity at room temperature = 8.0 poise.

Discussion

34.	A bead can slide on a smooth circular wire frame of radius r which is fixed in the vertical plane. The bead is displaced slightly from the highest point of the wire frame. The speed of the bead subsequently as a function of the angle θ made by the bead with the vertical line is
Answer» A bead can slide on a smooth circular wire frame of radius $r$ which is fixed in the vertical plane. The bead is displaced slightly from the highest point of the wire frame. The speed of the bead subsequently as a function of the angle $θ$ made by the bead with the vertical line is

Discussion

35.	Two particles are separated at a horizontal distance x as shown in figure. They are projected at the same time as shown in figure with different initial speed. The time after which the horizontal distance between the particles become zero is
Answer» Two particles are separated at a horizontal distance x as shown in figure. They are projected at the same time as shown in figure with different initial speed. The time after which the horizontal distance between the particles become zero is

35.

Two particles are separated at a horizontal distance x as shown in figure. They are projected at the same time as shown in figure with different initial speed. The time after which the horizontal distance between the particles become zero is

Answer»

Two particles are separated at a horizontal distance x as shown in figure. They are projected at the same time as shown in figure with different initial speed. The time after which the horizontal distance between the particles become zero is

Discussion

36.	How many moles of sucrose should be dissolved in 500 g of water so as to get a solution which has a difference of 104∘C between boiling point and freezing point. (Kf=1.86Kkgmol−1,Kb=0.52Kkgmol−1).
Answer» How many moles of sucrose should be dissolved in 500 g of water so as to get a solution which has a difference of $104^{\circ} C$ between boiling point and freezing point. $(K_{f} = 1.86 K k g m o l^{- 1}, K_{b} = 0.52 K k g m o l^{- 1})$ .

Discussion

37.	A sports car can accelerate uniformaly to a speed of 162 km/h in 5 sec. Its maximum breaking retardation is 6 m/s2. Minimum time in which it can travel 1 km starting from rest and ending at rest in seconds is?
Answer» A sports car can accelerate uniformaly to a speed of $162$ km/h in 5 sec. Its maximum breaking retardation is $6 m / s^{2}$ . Minimum time in which it can travel 1 km starting from rest and ending at rest in seconds is?

Discussion

38.	A ball is dropped into a well in which the water level is at a depth h below the ground. If the speed of sound be c, then the time after which the splash is heard will be given by
Answer» A ball is dropped into a well in which the water level is at a depth h below the ground. If the speed of sound be c, then the time after which the splash is heard will be given by

Discussion

39.	I can understand the statement that resultant of three non coplanar vectors can never be zero or minimum number of non coplanar vectors whose sum can be zero is four
Answer» I can understand the statement that resultant of three non coplanar vectors can never be zero or minimum number of non coplanar vectors whose sum can be zero is four

Discussion

40.	A parachutist drops first freely from an aeroplane for 10s and then parachute opens out. Now he descends with a net retardation of 2.5 m/ s2. If he falls out of the plane at a height of 2495 m and g=10 m/s2, his velocity on reaching the ground will be
Answer» A parachutist drops first freely from an aeroplane for 10s and then parachute opens out. Now he descends with a net retardation of 2.5 m/ $s^{2}$ . If he falls out of the plane at a height of 2495 m and g=10 m/ $s^{2}$ , his velocity on reaching the ground will be

Discussion

41.	A capacitor of capacitance C is charged by a battery of emf E and internal resistance r. A resistance 2r is also connected in series with the capacitor. The amount of heat liberated inside the battery by the time capacitor is charged to 50% of its steady state value is given as
Answer» A capacitor of capacitance $C$ is charged by a battery of emf $E$ and internal resistance $r$ . A resistance $2 r$ is also connected in series with the capacitor. The amount of heat liberated inside the battery by the time capacitor is charged to $50 %$ of its steady state value is given as

Discussion

42.	According to pressure equation, PV=1/3 M Vrms². =>nRT=1/3 M Vrms² => T directly proportional to M Vrms² According to mean Kinetic energy, KE(avg)=1/2 M Vrms² => KE(avg) directly proportional to M Vrms² This means.. M Vrms² directly proportional to KE(avg) T => M Vrms² /T = KE(avg) × proportionality constant So this means the avg Kinetic energy is inversely proportional to Absolute Temperature. But actually KE(avg) is directly proportional to T. Please clear my doubt
Answer» According to pressure equation, PV=1/3 M Vrms². =>nRT=1/3 M Vrms² => T directly proportional to M Vrms² According to mean Kinetic energy, KE(avg)=1/2 M Vrms² => KE(avg) directly proportional to M Vrms² This means.. M Vrms² directly proportional to KE(avg) T => M Vrms² /T = KE(avg) × proportionality constant So this means the avg Kinetic energy is inversely proportional to Absolute Temperature. But actually KE(avg) is directly proportional to T. Please clear my doubt

42.

According to pressure equation, PV=1/3 M Vrms². =>nRT=1/3 M Vrms² => T directly proportional to M Vrms² According to mean Kinetic energy, KE(avg)=1/2 M Vrms² => KE(avg) directly proportional to M Vrms² This means.. M Vrms² directly proportional to KE(avg) T => M Vrms² /T = KE(avg) × proportionality constant So this means the avg Kinetic energy is inversely proportional to Absolute Temperature. But actually KE(avg) is directly proportional to T. Please clear my doubt

Answer»

According to pressure equation, PV=1/3 M Vrms².

=>nRT=1/3 M Vrms²

=> T directly proportional to M Vrms²

According to mean Kinetic energy,

KE(avg)=1/2 M Vrms²

=> KE(avg) directly proportional to M Vrms²

This means.. M Vrms² directly proportional to KE(avg) T

=> M Vrms² /T = KE(avg) × proportionality constant

So this means the avg Kinetic energy is inversely proportional to Absolute Temperature. But actually KE(avg) is directly proportional to T. Please clear my doubt

Discussion

43.	The period of oscillation of a simple pendulum of constant length at earth surface is T. Its period inside a mine is
Answer» The period of oscillation of a simple pendulum of constant length at earth surface is T. Its period inside a mine is

43.

The period of oscillation of a simple pendulum of constant length at earth surface is T. Its period inside a mine is

Answer»

The period of oscillation of a simple pendulum of constant length at earth surface is T. Its period inside a mine is

Discussion

44.	An engine develops a power of 360 kw, when rotating at 30 revolutions per second. The Torque required to deliver this power is
Answer» An engine develops a power of 360 kw, when rotating at 30 revolutions per second. The Torque required to deliver this power is

Discussion

45.	The amplitude of two waves are in ratio 5 : 2. If all other conditions for the two waves are same, then what is the ratio of their energy densities
Answer» The amplitude of two waves are in ratio 5 : 2. If all other conditions for the two waves are same, then what is the ratio of their energy densities

Discussion

46.	An iron us dropped into a well sound of splash is heard after 4.23 second if the depth of the well is 78.4 m then find the speed of sound in air
Answer» An iron us dropped into a well sound of splash is heard after 4.23 second if the depth of the well is 78.4 m then find the speed of sound in air

Discussion

47.	In which of the following, the reaction proceeds towards completion
Answer» In which of the following, the reaction proceeds towards completion

47.

In which of the following, the reaction proceeds towards completion

Answer»

In which of the following, the reaction proceeds towards completion

Discussion

48.	If R1 and R2 are the radii of curvature of a double convex lens, which of the following will have the largest power?
Answer» If R₁ and R₂ are the radii of curvature of a double convex lens, which of the following will have the largest power?

Discussion

49.	A soap bubble is blown with the help of a mechanical pump at the mouth of a tube. The pump produces a certain increase per minute in the volume of the bubble, irrespective of its internal pressure. The graph between the pressure inside the soap bubble and time t will be-
Answer» A soap bubble is blown with the help of a mechanical pump at the mouth of a tube. The pump produces a certain increase per minute in the volume of the bubble, irrespective of its internal pressure. The graph between the pressure inside the soap bubble and time t will be-

Discussion

50.	Two point charges QA = 2 μ C and QA = -2 μC located 16 cm apart in vacuum. What is the electric field at the mid point O of the line AB joining the two charges?
Answer» Two point charges QA = 2 μ C and QA = -2 μC located 16 cm apart in vacuum. What is the electric field at the mid point O of the line AB joining the two charges?

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The net force on a body is varying with time as (2t + 3) N. Find the change in momentum of the body after 2 secs?

Two blocks of mass m1=4 kg and m2=2 kg, connected by a weightless rod on a plane having inclination of 37∘ is shown in figure. If the coefficient of dynamic friction is μ=0.25, then the common acceleration of the two blocks and the tension (T) in the rod are

The speed of a transverse wave travelling through a wire having a length 50 cm and mass 5.0 g is 80 m/s. The area of cross-section of the wire is 1.0 mm2 and its Young's modulus is 16×1011 N/m2. Find the extension in the wire with respect to its natural length.

Which of the following options are correct regarding the molar heat capacity (C) for the gas whose PV graph is shown below.

What is the magnitude of →v ?

In the figure shown, find the tension in the string connecting the blocks of mass 2 kg and 3 kg. Take g=10 m/s2

In the equation representing wave function, y=Asin(kx−ωt+ϕ0) The term phase is defined as:

The average time of motion of electrons between two successive collisions with fixed positive ions inside a conductor is called the ___ time

A particle of mass m moves with constant speed v on a circular path of radius r. Find the magnitude of average force on it in half revolution.

The area of cross-section, length, and density of a piece of a metal of atomic weight 60 are 10-6 m2, 1.0 m and 5 x 103 kgm-3 respectively. The number of free electrons per unit volume if every atom contributes one free electron is

When a bomb is thrown from an aeroplane(uniform motion), what is the initial velocity of throwing ball.

A string of length l along x− axis is fixed at both ends and is vibrating in second harmonic. If amplitude of incident wave is 2.5 mm, the equation of standing wave is (T is tension and μ is linear density)

electric charges are spread to volume the flux of electric field trough a spherical surface of radius 10cm sourrounding the charge 20Vm the flux over a cocentric sphere of radius 20cm will be

The density of a linear rod of length 'L' varies as p = A+Bx where x is the distance from the left end. Then the position of the centre of mass from the left end is

A rectangular lamina ABCD has same density along side AD but has increasing density along side AB. The density along side AB is given as ρ=ρ0+kx where ρ0 and k are constants and x is distance from the side AD. Find the distance of COM from side AD.

A uniform electric field is given by, E=−180^kV/m (a) What is the change in potential from zA=5cm to zB=15 cm? (b) How far apart along the z-axis are two points that differ in potential by 27 V?

It is given that complex numbers z1 and z2 satisfy |z1| = 2 and |z2| = 3. If the included angle of their corresponding vectors is 60o the ∣∣z1+z2z1−z2∣∣ can be expressed as √x7 where `x` is a natural number the `x` equals to.

A man running on a circular track of radius=20 m, Find the linear distance travelled by the man when he completes 5 revolutions?

If i jump of the building i will get hurt but while cats they jump of from fourth floor but still they do not get hurt.why?

When two bodies move uniformly towards each other, the distance between them diminishes by 16 m every 10 s. If bodies move in same direction with velocities of the same magnitude as before, the distance between them will decrease by 3 m in every 5 s. The velocity of each body is

A body of mass 2 kg is kept on a rough horizontal surface. If μs=0.5 and an external force of F=5 N is applied on the body, find the angle of friction. (Take g=10 m/s2)

The work function of a metal is 4.2 eV, its threshold wavelength will be

Three rods made of the same material and having the same cross-section,same length have been joined as shown in the ﬁgure. The extreme left and right ends are kept at 0∘C and 90∘C respectively. The temperature of the junction of the three rods will be

Which of the curves in figure represents the relation between Celsius and Fahrenheit temperatures?

What are the advantages of using AC over DC?

It is known that wax contracts on solidification. If molten wax is taken in a large vessel and it is allowed to cool slowly, then

A metre scale made of steel is calibrated at 20∘C to give correct reading. Find the distance between 50 cm mark and 51 cm mark if the scale is used at 10∘C. Coefficient of linear expansion of steel is 1.1×10−5 ∘C−1

A,B and C are voltmeters of resistance R,1.5R and 3R respectively. When some potential difference is applied between X and Y, the voltmeter readings are VA,VB and VC respectively. Then

If a man increases his speed by 2 m/s, his kinetic energy is doubled. The original speed of the man is

A bead can slide on a smooth circular wire frame of radius r which is fixed in the vertical plane. The bead is displaced slightly from the highest point of the wire frame. The speed of the bead subsequently as a function of the angle θ made by the bead with the vertical line is

Two particles are separated at a horizontal distance x as shown in figure. They are projected at the same time as shown in figure with different initial speed. The time after which the horizontal distance between the particles become zero is

How many moles of sucrose should be dissolved in 500 g of water so as to get a solution which has a difference of 104∘C between boiling point and freezing point. (Kf=1.86Kkgmol−1,Kb=0.52Kkgmol−1).

A sports car can accelerate uniformaly to a speed of 162 km/h in 5 sec. Its maximum breaking retardation is 6 m/s2. Minimum time in which it can travel 1 km starting from rest and ending at rest in seconds is?

A ball is dropped into a well in which the water level is at a depth h below the ground. If the speed of sound be c, then the time after which the splash is heard will be given by

I can understand the statement that resultant of three non coplanar vectors can never be zero or minimum number of non coplanar vectors whose sum can be zero is four

A parachutist drops first freely from an aeroplane for 10s and then parachute opens out. Now he descends with a net retardation of 2.5 m/ s2. If he falls out of the plane at a height of 2495 m and g=10 m/s2, his velocity on reaching the ground will be

A capacitor of capacitance C is charged by a battery of emf E and internal resistance r. A resistance 2r is also connected in series with the capacitor. The amount of heat liberated inside the battery by the time capacitor is charged to 50% of its steady state value is given as

The period of oscillation of a simple pendulum of constant length at earth surface is T. Its period inside a mine is

An engine develops a power of 360 kw, when rotating at 30 revolutions per second. The Torque required to deliver this power is

The amplitude of two waves are in ratio 5 : 2. If all other conditions for the two waves are same, then what is the ratio of their energy densities

An iron us dropped into a well sound of splash is heard after 4.23 second if the depth of the well is 78.4 m then find the speed of sound in air

In which of the following, the reaction proceeds towards completion

If R1 and R2 are the radii of curvature of a double convex lens, which of the following will have the largest power?

A soap bubble is blown with the help of a mechanical pump at the mouth of a tube. The pump produces a certain increase per minute in the volume of the bubble, irrespective of its internal pressure. The graph between the pressure inside the soap bubble and time t will be-

Two point charges QA = 2 μ C and QA = -2 μC located 16 cm apart in vacuum. What is the electric field at the mid point O of the line AB joining the two charges?