50278 + Interview Questions in Physics

1.	A ball of mass 1 kg is thrown with a velocity of 6 m/s at a stone of unknown mass initially at rest. If the velocity of the stone after the elastic collision with the ball is 1.5 m/s, what is the mass of the stone?
Answer» A ball of mass $1 kg$ is thrown with a velocity of $6 m/s$ at a stone of unknown mass initially at rest. If the velocity of the stone after the elastic collision with the ball is $1.5 m/s$ , what is the mass of the stone?

Discussion

2.	tan13π12=2−√n. Then n=
Answer» $t a n \frac{13 π}{12} = 2 - \sqrt{n}$ . Then $n =$

Discussion

3.	A particle starts with a velocity of 3 ms−1 and moves in a straight line with a retardation of 0.2 ms−2. The first time at which the particle is 20 m from the starting point is
Answer» A particle starts with a velocity of $3 {ms}^{- 1}$ and moves in a straight line with a retardation of $0.2 {ms}^{- 2}$ . The first time at which the particle is $20 m$ from the starting point is

Discussion

4.	If Electric field in a region is given by E=x2^i+y^j+^k. What is the potential of the point (1,2,3) given the potential of the origin is 10V?
Answer» If Electric field in a region is given by $E = x^{2}^i + y^j +^k$ . What is the potential of the point (1,2,3) given the potential of the origin is 10V?

Discussion

5.	How to convert 9o kPa to atm? And why in previous problem it is converted to atm not to Pascal?
Answer» How to convert 9o kPa to atm? And why in previous problem it is converted to atm not to Pascal?

Discussion

6.	The height of a mercury barometer is 75 cm at sea level and 50 cm at the top of a hill. Ratio of density of mercury to that of air is 104. The height of the hill is
Answer» The height of a mercury barometer is 75 cm at sea level and 50 cm at the top of a hill. Ratio of density of mercury to that of air is $10^{4}$ . The height of the hill is

Discussion

7.	Two moving coil galvanomenters M1 and M2 having same spring constants and have the following specifications. for galvanomter M1, R1=10 Ω,N1=30, A1=3.6×10−3 m2,B1=0.25 T, for galvanomter M2,R2=14 Ω,N2=42, A2=1.8×10−3 m2,B2=0.5 T Find the ratio of current sensitivity of galavnomter M1 to galvanomter M2
Answer» Two moving coil galvanomenters $M_{1}$ and $M_{2}$ having same spring constants and have the following specifications. for galvanomter $M_{1}$ , $R_{1} = 10 Ω, N_{1} = 30$ , $A_{1} = 3.6 \times 10^{- 3} m^{2}, B_{1} = 0.25 T$ , for galvanomter $M_{2}, R_{2} = 14 Ω, N_{2} = 42,$ $A_{2} = 1.8 \times 10^{- 3} m^{2}, B_{2} = 0.5 T$ Find the ratio of current sensitivity of galavnomter $M_{1}$ to galvanomter $M_{2}$

Discussion

8.	Two capacitors of capacitance C and 2C, are charged to potential differences V ad 2Vrespectively. If the two positive plates are connected together and the two negative plates are connected together, then this system of capacitance
Answer» Two capacitors of capacitance C and 2C, are charged to potential differences V ad 2Vrespectively. If the two positive plates are connected together and the two negative plates are connected together, then this system of capacitance

Discussion

9.	The equation of a wave on a string of linear mass density 0.04 kg/m is given by, y=0.02(m)sin[2π(t(s)0.04−x(m)0.50)]. The tension in the string is
Answer» The equation of a wave on a string of linear mass density 0.04 kg/m is given by, $y = 0.02 (m) s i n [2 π (\frac{t (s)}{0.04} - \frac{x (m)}{0.50})]$ . The tension in the string is

Discussion

10.	A body is revolving with a constant speed along a circle. If its direction of motion is reversed but the speed remains the same, then which of the following statement is true
Answer» A body is revolving with a constant speed along a circle. If its direction of motion is reversed but the speed remains the same, then which of the following statement is true

Discussion

11.	Four resistances are connected to a DC battery as shown in ﬁgure. Maximum power will be developed across___ ohm resistance.
Answer» Four resistances are connected to a DC battery as shown in ﬁgure. Maximum power will be developed across___ ohm resistance.

Discussion

12.	Two particles of masses 1kg and 3kg have position vectors 2^i+3^j+4^k and −2^i+3^j−4^k respectively. The centre of mass has a position vector:
Answer» Two particles of masses 1kg and 3kg have position vectors $2^i + 3^j + 4^k$ and $- 2^i + 3^j - 4^k$ respectively. The centre of mass has a position vector:

Discussion

13.	The internal resistance of a cell of e.m.f 2V is 0.2 Ω. It is connected to a resistance of 4 Ω. The voltage across the cell will be
Answer» The internal resistance of a cell of e.m.f $2 V$ is $0.2 Ω$ . It is connected to a resistance of $4 Ω$ . The voltage across the cell will be

Discussion

14.	Small amplitude progressive wave in a stretched string has a speed of 100 cm/s, and frequency 100 Hz. The phase difference between two points 2.75 cm apart on the string in radians, is
Answer» Small amplitude progressive wave in a stretched string has a speed of 100 cm/s, and frequency 100 Hz. The phase difference between two points 2.75 cm apart on the string in radians, is

Discussion

15.	An old man goes for morning walk on a semi-circular track of radius 28 m, if he starts from one end of the track and reaches to other end, the distance covered by the man will be (Take π=227)
Answer» An old man goes for morning walk on a semi-circular track of radius $28 m$ , if he starts from one end of the track and reaches to other end, the distance covered by the man will be (Take $π = \frac{22}{7}$ )

Discussion

16.	A plank of mass 2 kg and length 9.5 m is placed on a horizontal floor. A small block of mass 1 kg is placed on top of the plank, at its right extreme end. The coefficient of friction between plank and floor is 0.5 and that between plank and block is 0.2. If a horizontal force of 30 N starts acting on the plank to the right, the time after which the block will fall off the plank is (Take g=10 ms−2)
Answer» A plank of mass $2 kg$ and length $9.5 m$ is placed on a horizontal floor. A small block of mass $1 kg$ is placed on top of the plank, at its right extreme end. The coefficient of friction between plank and floor is $0.5$ and that between plank and block is $0.2$ . If a horizontal force of $30 N$ starts acting on the plank to the right, the time after which the block will fall off the plank is (Take $g = 10 {ms}^{- 2}$ )

Discussion

17.	A force F acting on a particle depends on displacement as F∝xn. Then, power delivered by the force depends on x as:
Answer» A force $F$ acting on a particle depends on displacement as $F \propto x^{n}$ . Then, power delivered by the force depends on $x$ as:

Discussion

18.	Show that the ratio of the magnetic dipole moment to the angular momentum (l = mvr) is a universal constant for hydrogen-like atoms and ions. Find its value.
Answer» Show that the ratio of the magnetic dipole moment to the angular momentum (l = mvr) is a universal constant for hydrogen-like atoms and ions. Find its value.

Discussion

19.	At what point in its path does a projectile thrown from the ground has minimum and maximum speed?
Answer» At what point in its path does a projectile thrown from the ground has minimum and maximum speed?

Discussion

20.	One fermi is equal to
Answer» One fermi is equal to

Discussion

21.	A train starts from rest and accelerate uniformly at the rate of 5 m/s2 for 5 sec. Calculate the velocity of train in 5 sec.
Answer» A train starts from rest and accelerate uniformly at the rate of $5 {m/s}^{2}$ for $5 sec$ . Calculate the velocity of train in $5 sec$ .

Discussion

22.	In the figure shown, find the tension ‘T′ in the string to prevent the body from sliding down the plane. Assume the string to be horizontal.
Answer» In the figure shown, find the tension $‘ T^{'}$ in the string to prevent the body from sliding down the plane. Assume the string to be horizontal.

Discussion

23.	A spherical drop of capacitance 12 μF is broken into eight drops of equal radius. Then, what is the capacitance of each small drop in μF?
Answer» A spherical drop of capacitance $12 μ F$ is broken into eight drops of equal radius. Then, what is the capacitance of each small drop in $μ F$ ?

Discussion

24.	An aircraft flies at 400 km/h in still air. A wind of 200√2 km/h is blowing from the south. The pilot wishes to travel from A to a point B north-east of A. The direction he must steer is
Answer» An aircraft flies at $400 k m / h$ in still air. A wind of $200 \sqrt{2} k m / h$ is blowing from the south. The pilot wishes to travel from $A$ to a point $B$ north-east of $A$ . The direction he must steer is

Discussion

25.	A ring having linear mass density 5 kg/m and radius 0.5 m is rotated about the axis passing through it's centre and perpendicular to it's plane. Find the moment of inertia (MI) of the ring about the required axis.
Answer» A ring having linear mass density $5 kg/m$ and radius $0.5 m$ is rotated about the axis passing through it's centre and perpendicular to it's plane. Find the moment of inertia ( $MI$ ) of the ring about the required axis.

Discussion

26.	Find the value of cos(3π2+x)cos(2π+x)[cot(3π2−x)+cot(2π+x)]. Given, sin2x+cos2x=1
Answer» Find the value of $cos (\frac{3 π}{2} + x) cos (2 π + x) [cot (\frac{3 π}{2} - x) + cot (2 π + x)]$ . Given, ${sin}^{2} x + {cos}^{2} x = 1$

Discussion

27.	Angular acceleration of a circular disc which is initially at rest, about a stationary axis is α=8cos2t (in rad/s2). Which of the following graphs correctly represents the variation of angular velocity with respect to time ?
Answer» Angular acceleration of a circular disc which is initially at rest, about a stationary axis is $α = 8 cos 2 t$ (in ${rad/s}^{2}$ ). Which of the following graphs correctly represents the variation of angular velocity with respect to time ?

Discussion

28.	Two charged particles placed at a separation of 20 cm exert 20 N of Coulomb force on each other. What will be the force if the separation is increased to 25 cm ?
Answer» Two charged particles placed at a separation of 20 cm exert 20 N of Coulomb force on each other. What will be the force if the separation is increased to 25 cm ?

Discussion

29.	Photoelectric effect supports quantum nature of light because
Answer» Photoelectric effect supports quantum nature of light because

Discussion

30.	An ideal gas acting as a working substance for a heat engine. The heat interaction involved during the process are Q1=9605 J and Q2=−8565 J respectively. Then efficiency of the heat engine is
Answer» An ideal gas acting as a working substance for a heat engine. The heat interaction involved during the process are $Q_{1} = 9605 J$ and $Q_{2} = - 8565 J$ respectively. Then efficiency of the heat engine is

Discussion

31.	In the figure shown, what is the value of mass ‘m’ such that block A slides up with a constant velocity. Take g=10 m/s2, Coefficient of friction between inclined plane and block A is 0.5.
Answer» In the figure shown, what is the value of mass ‘ $m$ ’ such that block $A$ slides up with a constant velocity. Take $g = 10 {m/s}^{2}$ , Coefficient of friction between inclined plane and block $A$ is $0.5$ .

Discussion

32.	A cannon shell moving along a straight line, explodes into two parts. Just after the explosion, one part moves with momentum 100 Ns making an angle 30∘ with the original line of motion. The minimum momentum of the other part of the shell after the explosion is
Answer» A cannon shell moving along a straight line, explodes into two parts. Just after the explosion, one part moves with momentum $100 Ns$ making an angle $30^{\circ}$ with the original line of motion. The minimum momentum of the other part of the shell after the explosion is

Discussion

33.	A steel ring of radius r and cross-section area 'A' is fitted on to a wooden disc of radius R(R> r). If Young's modulus be E, then the force with which the steel ring is expanded is
Answer» A steel ring of radius r and cross-section area 'A' is fitted on to a wooden disc of radius R(R $>$ r). If Young's modulus be E, then the force with which the steel ring is expanded is

Discussion

34.	A particle of mass m is projected from the ground with initial linear momentum p (magnitude) such that to have maximum possible range. Its minimum kinetic energy will be
Answer» A particle of mass $m$ is projected from the ground with initial linear momentum $p$ (magnitude) such that to have maximum possible range. Its minimum kinetic energy will be

Discussion

35.	A projectile s aimed at a target on a horizontal plane but falls 8 m short, when the angle of projection is 150, while it overshoots by 16 m, when the angle is 350. The angle of projection to hit the target is
Answer» A projectile s aimed at a target on a horizontal plane but falls 8 m short, when the angle of projection is $15^{0}$ , while it overshoots by 16 m, when the angle is $35^{0}$ . The angle of projection to hit the target is

Discussion

36.	A body of m is moving in a straight line at a constant speed v. Its kinetic energy is k and the magnitude of its momentum is p. Which of the following relations is/are correct?
Answer» A body of m is moving in a straight line at a constant speed v. Its kinetic energy is k and the magnitude of its momentum is p. Which of the following relations is/are correct?

Discussion

37.	A wire elongates by 1.0 mm when a load W is hanged from it. If this wire goes over a pulley and two weights W each are hung at the two ends, the elongation of the wire will be
Answer» A wire elongates by 1.0 mm when a load W is hanged from it. If this wire goes over a pulley and two weights W each are hung at the two ends, the elongation of the wire will be

Discussion

38.	An ideal gas is filled in a cylinder, which is fitted with a movable non-conducting piston as shown in the figure. The gas in the cylinder is heated slowly. The gas expands and pistons moves towards right. If the temperature of the gas is increased slowly from T0 to 2T0, find the displacement of the piston. (Given atmospheric pressure = P0 and area of cross-section of the cylinder = A).
Answer» An ideal gas is filled in a cylinder, which is fitted with a movable non-conducting piston as shown in the figure. The gas in the cylinder is heated slowly. The gas expands and pistons moves towards right. If the temperature of the gas is increased slowly from $T_{0}$ to $2 T_{0}$ , find the displacement of the piston. (Given atmospheric pressure = $P_{0}$ and area of cross-section of the cylinder = $A$ ).

Discussion

39.	Rank the following velocities according to the kinetic energy a particle will have with each velocity, greatest first: (i) →v=4^i+3^j (ii) →v=−4^i+3^j (iii) →v=−3^i+4^j (iv) →v=3^i−4^j (v) →v=5^i (vi) →v = 5ms at 30∘ to the horizontal.
Answer» Rank the following velocities according to the kinetic energy a particle will have with each velocity, greatest first: (i) $\to v = 4^i + 3^j$ (ii) $\to v = - 4^i + 3^j$ (iii) $\to v = - 3^i + 4^j$ (iv) $\to v = 3^i - 4^j$ (v) $\to v = 5^i$ (vi) $\to v$ = $5 \frac{m}{s}$ at $30^{\circ}$ to the horizontal.

39.

Rank the following velocities according to the kinetic energy a particle will have with each velocity, greatest first: (i) →v=4^i+3^j (ii) →v=−4^i+3^j (iii) →v=−3^i+4^j (iv) →v=3^i−4^j (v) →v=5^i (vi) →v = 5ms at 30∘ to the horizontal.

Answer»

Rank the following velocities according to the kinetic energy a particle will have with each

velocity, greatest first: (i) $\to v = 4^i + 3^j$ (ii) $\to v = - 4^i + 3^j$ (iii) $\to v = - 3^i + 4^j$ (iv) $\to v = 3^i - 4^j$ (v) $\to v = 5^i$ (vi) $\to v$ = $5 \frac{m}{s}$ at $30^{\circ}$ to the horizontal.

Discussion

40.	Potassium crystallises in BCC unit cell . Mass of 1 unit cell is
Answer» Potassium crystallises in BCC unit cell . Mass of 1 unit cell is

Discussion

41.	Vector →A=5^i+4^j+3^k is rotated around Z-axis such that its projection on the x-y plane is rotated through 180∘.Choose the correct option?
Answer» Vector $\to A = 5^i + 4^j + 3^k$ is rotated around Z-axis such that its projection on the x-y plane is rotated through $180^{\circ}$ .Choose the correct option?

41.

Vector →A=5^i+4^j+3^k is rotated around Z-axis such that its projection on the x-y plane is rotated through 180∘.Choose the correct option?

Answer»

Vector $\to A = 5^i + 4^j + 3^k$ is rotated around Z-axis such that its projection on the x-y plane is rotated through $180^{\circ}$ .Choose the correct option?

Discussion

42.	Calculate the energy in joule corresponding to light of wavelength 45 nm (h=6.63×10−34Js;C=3×108ms−1)
Answer» Calculate the energy in joule corresponding to light of wavelength $45 n m (h = 6.63 \times 10^{- 34} J s; C = 3 \times 10^{8} m s^{- 1})$

Discussion

43.	f(x)=asinx+2cosxsinx+cosx is increasing for ∀xϵR,then a ϵ
Answer» $f (x) = \frac{a s i n x + 2 c o s x}{s i n x + c o s x} is increasing for \forall x ϵ R, t h e n a ϵ$

Discussion

44.	If net external force on a body adds up to zero, which of the following statements are not necessarily true?
Answer» If net external force on a body adds up to zero, which of the following statements are not necessarily true?

Discussion

45.	A spacecraft of mass M explodes into two parts when its velocity is V. After the explosion, one part of mass m is left stationary. What is the velocity of the other part?
Answer» A spacecraft of mass $M$ explodes into two parts when its velocity is $V$ . After the explosion, one part of mass m is left stationary. What is the velocity of the other part?

Discussion

46.	Find the expression for the time period of a pendulum using dimensional analysis.
Answer» Find the expression for the time period of a pendulum using dimensional analysis.

Discussion

47.	In young's double slit experiment, the intensity at a point where the path difference is λ6(λ being the wavelength of light used) is I . If I0 denotes the maximum intensity, II0 is equal to
Answer» In young's double slit experiment, the intensity at a point where the path difference is $\frac{λ}{6}$ ( $λ$ being the wavelength of light used) is $I$ . If $I_{0}$ denotes the maximum intensity, $\frac{I}{I_{0}}$ is equal to

Discussion

48.	There is a massless pulley which is going upward with an acceleration a=5tm/s2. A string is passing over the pulley as shown in the figure. At one end of the string a plank of mass 2m kg is attached and at the other end a small ball of mass m kg is attached. It is given that after 1 sec it just passes the plank then if length of plank is x + 0.8 . Find x. ___
Answer» There is a massless pulley which is going upward with an acceleration $a = 5 t m / s^{2}$ . A string is passing over the pulley as shown in the figure. At one end of the string a plank of mass 2m kg is attached and at the other end a small ball of mass m kg is attached. It is given that after 1 sec it just passes the plank then if length of plank is x + 0.8 . Find x. ___

Discussion

49.	A boy of mass m is in touch with the wall of a rotating cylinder. The boy will stay intouch with wall and rotate if
Answer» A boy of mass m is in touch with the wall of a rotating cylinder. The boy will stay intouch with wall and rotate if

49.

A boy of mass m is in touch with the wall of a rotating cylinder. The boy will stay intouch with wall and rotate if

Answer»

A boy of mass m is in touch with the wall of a rotating cylinder. The boy will stay intouch with wall and rotate if

Discussion

50.	A capacitor of capacitance 2 μF is charged to a potential difference of 5 V. Now the charging battery is disconnected and the capacitor is connected in parallel to a 5 Ω and R resistance as shown in figure. If total heat produced in 5 Ω resistance is 10 μJ, then R is
Answer» A capacitor of capacitance $2 μ F$ is charged to a potential difference of 5 V. Now the charging battery is disconnected and the capacitor is connected in parallel to a $5 Ω$ and R resistance as shown in figure. If total heat produced in $5 Ω$ resistance is $10 μ J$ , then R is

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A ball of mass 1 kg is thrown with a velocity of 6 m/s at a stone of unknown mass initially at rest. If the velocity of the stone after the elastic collision with the ball is 1.5 m/s, what is the mass of the stone?

tan13π12=2−√n. Then n=

A particle starts with a velocity of 3 ms−1 and moves in a straight line with a retardation of 0.2 ms−2. The first time at which the particle is 20 m from the starting point is

If Electric field in a region is given by E=x2^i+y^j+^k. What is the potential of the point (1,2,3) given the potential of the origin is 10V?

How to convert 9o kPa to atm? And why in previous problem it is converted to atm not to Pascal?

The height of a mercury barometer is 75 cm at sea level and 50 cm at the top of a hill. Ratio of density of mercury to that of air is 104. The height of the hill is

Two capacitors of capacitance C and 2C, are charged to potential differences V ad 2Vrespectively. If the two positive plates are connected together and the two negative plates are connected together, then this system of capacitance

The equation of a wave on a string of linear mass density 0.04 kg/m is given by, y=0.02(m)sin[2π(t(s)0.04−x(m)0.50)]. The tension in the string is

A body is revolving with a constant speed along a circle. If its direction of motion is reversed but the speed remains the same, then which of the following statement is true

Four resistances are connected to a DC battery as shown in ﬁgure. Maximum power will be developed across___ ohm resistance.

Two particles of masses 1kg and 3kg have position vectors 2^i+3^j+4^k and −2^i+3^j−4^k respectively. The centre of mass has a position vector:

The internal resistance of a cell of e.m.f 2V is 0.2 Ω. It is connected to a resistance of 4 Ω. The voltage across the cell will be

Small amplitude progressive wave in a stretched string has a speed of 100 cm/s, and frequency 100 Hz. The phase difference between two points 2.75 cm apart on the string in radians, is

An old man goes for morning walk on a semi-circular track of radius 28 m, if he starts from one end of the track and reaches to other end, the distance covered by the man will be (Take π=227)

A force F acting on a particle depends on displacement as F∝xn. Then, power delivered by the force depends on x as:

Show that the ratio of the magnetic dipole moment to the angular momentum (l = mvr) is a universal constant for hydrogen-like atoms and ions. Find its value.

At what point in its path does a projectile thrown from the ground has minimum and maximum speed?

One fermi is equal to

A train starts from rest and accelerate uniformly at the rate of 5 m/s2 for 5 sec. Calculate the velocity of train in 5 sec.

In the figure shown, find the tension ‘T′ in the string to prevent the body from sliding down the plane. Assume the string to be horizontal.

A spherical drop of capacitance 12 μF is broken into eight drops of equal radius. Then, what is the capacitance of each small drop in μF?

An aircraft flies at 400 km/h in still air. A wind of 200√2 km/h is blowing from the south. The pilot wishes to travel from A to a point B north-east of A. The direction he must steer is

A ring having linear mass density 5 kg/m and radius 0.5 m is rotated about the axis passing through it's centre and perpendicular to it's plane. Find the moment of inertia (MI) of the ring about the required axis.

Find the value of cos(3π2+x)cos(2π+x)[cot(3π2−x)+cot(2π+x)]. Given, sin2x+cos2x=1

Angular acceleration of a circular disc which is initially at rest, about a stationary axis is α=8cos2t (in rad/s2). Which of the following graphs correctly represents the variation of angular velocity with respect to time ?

Two charged particles placed at a separation of 20 cm exert 20 N of Coulomb force on each other. What will be the force if the separation is increased to 25 cm ?

Photoelectric effect supports quantum nature of light because

An ideal gas acting as a working substance for a heat engine. The heat interaction involved during the process are Q1=9605 J and Q2=−8565 J respectively. Then efficiency of the heat engine is

In the figure shown, what is the value of mass ‘m’ such that block A slides up with a constant velocity. Take g=10 m/s2, Coefficient of friction between inclined plane and block A is 0.5.

A cannon shell moving along a straight line, explodes into two parts. Just after the explosion, one part moves with momentum 100 Ns making an angle 30∘ with the original line of motion. The minimum momentum of the other part of the shell after the explosion is

A steel ring of radius r and cross-section area 'A' is fitted on to a wooden disc of radius R(R&gt; r). If Young's modulus be E, then the force with which the steel ring is expanded is

A particle of mass m is projected from the ground with initial linear momentum p (magnitude) such that to have maximum possible range. Its minimum kinetic energy will be

A projectile s aimed at a target on a horizontal plane but falls 8 m short, when the angle of projection is 150, while it overshoots by 16 m, when the angle is 350. The angle of projection to hit the target is

A body of m is moving in a straight line at a constant speed v. Its kinetic energy is k and the magnitude of its momentum is p. Which of the following relations is/are correct?

A wire elongates by 1.0 mm when a load W is hanged from it. If this wire goes over a pulley and two weights W each are hung at the two ends, the elongation of the wire will be

Rank the following velocities according to the kinetic energy a particle will have with each velocity, greatest first: (i) →v=4^i+3^j (ii) →v=−4^i+3^j (iii) →v=−3^i+4^j (iv) →v=3^i−4^j (v) →v=5^i (vi) →v = 5ms at 30∘ to the horizontal.

Potassium crystallises in BCC unit cell . Mass of 1 unit cell is

Vector →A=5^i+4^j+3^k is rotated around Z-axis such that its projection on the x-y plane is rotated through 180∘.Choose the correct option?

Calculate the energy in joule corresponding to light of wavelength 45 nm (h=6.63×10−34Js;C=3×108ms−1)

f(x)=asinx+2cosxsinx+cosx is increasing for ∀xϵR,then a ϵ

If net external force on a body adds up to zero, which of the following statements are not necessarily true?

A spacecraft of mass M explodes into two parts when its velocity is V. After the explosion, one part of mass m is left stationary. What is the velocity of the other part?

Find the expression for the time period of a pendulum using dimensional analysis.

In young's double slit experiment, the intensity at a point where the path difference is λ6(λ being the wavelength of light used) is I . If I0 denotes the maximum intensity, II0 is equal to

A boy of mass m is in touch with the wall of a rotating cylinder. The boy will stay intouch with wall and rotate if

A capacitor of capacitance 2 μF is charged to a potential difference of 5 V. Now the charging battery is disconnected and the capacitor is connected in parallel to a 5 Ω and R resistance as shown in figure. If total heat produced in 5 Ω resistance is 10 μJ, then R is

A steel ring of radius r and cross-section area 'A' is fitted on to a wooden disc of radius R(R> r). If Young's modulus be E, then the force with which the steel ring is expanded is