50278 + Interview Questions in Physics

1.	Why Electric field lines are said to originate from positive charge?????
Answer» Why Electric field lines are said to originate from positive charge?????

Discussion

2.	A steady electric current is flowing through a cylindrical conductor.Then select the correct statement. 1. The electric field in the vicinity of the conductor is zero. 2. The magnetic field in the vicinity of the conductor is zero. 3. The electric field at the axis of the conductor is zero. 4. The magnetic field at the axis of the conductor is zero.
Answer» A steady electric current is flowing through a cylindrical conductor.Then select the correct statement. 1. The electric field in the vicinity of the conductor is zero. 2. The magnetic field in the vicinity of the conductor is zero. 3. The electric field at the axis of the conductor is zero. 4. The magnetic field at the axis of the conductor is zero.

2.

A steady electric current is flowing through a cylindrical conductor.Then select the correct statement. 1. The electric field in the vicinity of the conductor is zero. 2. The magnetic field in the vicinity of the conductor is zero. 3. The electric field at the axis of the conductor is zero. 4. The magnetic field at the axis of the conductor is zero.

Answer»

A steady electric current is flowing through a cylindrical conductor.Then select the correct statement.
1. The electric field in the vicinity of the conductor is zero.
2. The magnetic field in the vicinity of the conductor is zero.
3. The electric field at the axis of the conductor is zero.
4. The magnetic field at the axis of the conductor is zero.

Discussion

3.	At what temperature the mean speed of the molecules of hydrogen gas equals the escape speed from the earth?
Answer» At what temperature the mean speed of the molecules of hydrogen gas equals the escape speed from the earth?

Discussion

4.	Two spherical conductor A and B having equal radii and carrying equal charge s in them repel each other with a force F when placed apart at some distance.A third uncharged spherical conductor having same radii as that A is brought in contact with A and then B and finally removed away from both .The new force of repulsion between A and B is
Answer» Two spherical conductor A and B having equal radii and carrying equal charge s in them repel each other with a force F when placed apart at some distance.A third uncharged spherical conductor having same radii as that A is brought in contact with A and then B and finally removed away from both .The new force of repulsion between A and B is

Discussion

5.	Which main standards are used in various functional areas?
Answer» Which main standards are used in various functional areas?

Discussion

6.	Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional forces are 10% of energy. How much power is generated by the turbine?(g=10 m/s2)
Answer» Water falls from a height of $60 m$ at the rate of $15 k g / s$ to operate a turbine. The losses due to frictional forces are 10% of energy. How much power is generated by the turbine? $(g = 10 m / s^{2})$

Discussion

7.	A horizontal force of 10 N is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is 0.2. The weight of the block is
Answer» A horizontal force of $10 N$ is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is $0.2$ . The weight of the block is

Discussion

8.	what does the term "unit time" refer to? is it one second?
Answer» what does the term "unit time" refer to? is it one second?

Discussion

9.	If a body A of mass M is thrown with velocity V at an angle of 30∘ to the horizontal and another body B of the same mass is thrown with the same speed at an angle of 60∘ to the horizontal. The ratio of horizontal range of A to B will be
Answer» If a body A of mass M is thrown with velocity V at an angle of $30^{\circ}$ to the horizontal and another body B of the same mass is thrown with the same speed at an angle of $60^{\circ}$ to the horizontal. The ratio of horizontal range of A to B will be

Discussion

10.	A body of density d1 is counterpoised by Mg of weights of density d2 in air of density d. Then the true mass of the body is
Answer» A body of density $d_{1}$ is counterpoised by Mg of weights of density $d_{2}$ in air of density d. Then the true mass of the body is

Discussion

11.	A rod of length L and uniform cross-sectional area has varying thermal conductivity which changes linearly from 2K at end B to K at the other end A. The ends A and B of the rod are maintained at constant temperature 100∘C and 0∘C, respectively. At steady state, the graph of temperature : T=T(x) where x= distance from end A will be
Answer» A rod of length $L$ and uniform cross-sectional area has varying thermal conductivity which changes linearly from $2 K$ at end $B$ to $K$ at the other end $A$ . The ends $A$ and $B$ of the rod are maintained at constant temperature $100^{\circ} C$ and $0^{\circ} C$ , respectively. At steady state, the graph of temperature : $T = T (x)$ where $x =$ distance from end $A$ will be

Discussion

12.	Two equal charges q of opposite sign separated by a distance 2a constitute an electric dipole of dipole moment p . If P is a point at a distance r from the centre of the dipole and the line joining the centre of the dipole to this point makes an angle θ with the axis of the dipole, then the potential at P is given by (r >> 2a) (Where p = 2qa)
Answer» Two equal charges q of opposite sign separated by a distance 2a constitute an electric dipole of dipole moment p . If P is a point at a distance r from the centre of the dipole and the line joining the centre of the dipole to this point makes an angle $θ$ with the axis of the dipole, then the potential at P is given by (r >> 2a) (Where p = 2qa)

Discussion

13.	In Ballmer series of line of hydrogen spectrum the third line from red end corresponds to which inner orbit jump of electron for Bohr orbit in hydrogen atom. I have got the solution of this question earlier too but I could not understand the solution .please give the solution in a little more explanative and detailed manner.
Answer» In Ballmer series of line of hydrogen spectrum the third line from red end corresponds to which inner orbit jump of electron for Bohr orbit in hydrogen atom. I have got the solution of this question earlier too but I could not understand the solution .please give the solution in a little more explanative and detailed manner.

13.

In Ballmer series of line of hydrogen spectrum the third line from red end corresponds to which inner orbit jump of electron for Bohr orbit in hydrogen atom. I have got the solution of this question earlier too but I could not understand the solution .please give the solution in a little more explanative and detailed manner.

Answer»

In Ballmer series of line of hydrogen spectrum the third line from red end corresponds to which inner orbit jump of electron for Bohr orbit in hydrogen atom.

I have got the solution of this question earlier too but I could not understand the solution .please give the solution in a little more explanative and detailed manner.

Discussion

14.	The time period of a second's pendulum is 2 sec. The spherical bob which is empty from inside has a mass of 50 gm. This is now replaced by another solid bob of same radius but having different mass of 100 gm. The new time period will be
Answer» The time period of a second's pendulum is 2 sec. The spherical bob which is empty from inside has a mass of 50 gm. This is now replaced by another solid bob of same radius but having different mass of 100 gm. The new time period will be

Discussion

15.	If two conducting spheres are separately charged and then brought in contact, then
Answer» If two conducting spheres are separately charged and then brought in contact, then

Discussion

16.	A uniform metal rod is used as a bar pendulum. If the room temperature rises by 10∘C, and the coefficient of linear expansion of the metal of the rod is 2 ´ 10−6per∘C , the period of the pendulum will have percentage increase of
Answer» A uniform metal rod is used as a bar pendulum. If the room temperature rises by $10^{\circ} C$ , and the coefficient of linear expansion of the metal of the rod is 2 ´ $10^{- 6} p e r^{\circ} C$ , the period of the pendulum will have percentage increase of

16.

A uniform metal rod is used as a bar pendulum. If the room temperature rises by 10∘C, and the coefficient of linear expansion of the metal of the rod is 2 ´ 10−6per∘C , the period of the pendulum will have percentage increase of

Answer»

A uniform metal rod is used as a bar pendulum. If the room temperature rises by $10^{\circ} C$ , and the coefficient of linear expansion of the metal of the rod is 2 ´ $10^{- 6} p e r^{\circ} C$ , the period of the pendulum will have percentage increase of

Discussion

17.	A small metal sphere, carrying a net charge of q1=−2μC, is held in a stationery position by insulating supports. A second small metal sphere, with a net charge of q2=−8μC and mass 1.50g is projected towards q1. When the two spheres are 0.800m apart, q2 is moving towards q1 with speed 20 ms−1 as shown in the figure. Assume that the two spheres can be treated as point charges. You can ignore the force of gravity. The speed of q2 when the spheres are 0.400 m apart is
Answer» A small metal sphere, carrying a net charge of $q_{1} = - 2 μ C$ , is held in a stationery position by insulating supports. A second small metal sphere, with a net charge of $q_{2} = - 8 μ C$ and mass 1.50g is projected towards $q_{1}$ . When the two spheres are $0.800 m$ apart, $q_{2}$ is moving towards $q_{1}$ with speed $20 m s^{- 1}$ as shown in the figure. Assume that the two spheres can be treated as point charges. You can ignore the force of gravity. The speed of $q_{2}$ when the spheres are 0.400 m apart is

Discussion

18.	A body of weight 50 N is dragged slowly with constant velocity on a horizontal surface as shown in the figure, with a force of F=28.2 N at an angle of 45∘ with horizontal. The net contact force acting on the body will be
Answer» A body of weight $50 N$ is dragged slowly with constant velocity on a horizontal surface as shown in the figure, with a force of $F = 28.2 N$ at an angle of $45^{\circ}$ with horizontal. The net contact force acting on the body will be

Discussion

19.	The equation of a travelling wave is y = 60 cos (1800t – 6x) where y is in microns, t in seconds and x in metres. The ratio of maximum particle velocity to velocity of wave propagation is
Answer» The equation of a travelling wave is y = 60 cos (1800t – 6x) where y is in microns, t in seconds and x in metres. The ratio of maximum particle velocity to velocity of wave propagation is

Discussion

20.	Energy required to move a body of mass ‘m’ from an orbit of radius 2R to 3R is
Answer» Energy required to move a body of mass ‘m’ from an orbit of radius 2R to 3R is

Discussion

21.	A projectile is fired with some velocity making certain angle with the horizontal. Which of the following graphs is the best representation for the kinetic energy of a projectile (KE) versus its horizontal displacement (x)?
Answer» A projectile is fired with some velocity making certain angle with the horizontal. Which of the following graphs is the best representation for the kinetic energy of a projectile $(K E)$ versus its horizontal displacement $(x)$ ?

Discussion

22.	The magnetic field in a region is given by →B=→kB0Ly where L is a fixed length. A conducting rod of length L lies along the Y -axis between the origin and the point (0,L,0). IF the rod moves with a velocity v=v0→i, find the emf induced between the ends of the rod.
Answer» The magnetic field in a region is given by $\to B = \to k \frac{B_{0}}{L} y$ where L is a fixed length. A conducting rod of length L lies along the Y -axis between the origin and the point (0,L,0). IF the rod moves with a velocity $v = v_{0} \to i$ , find the emf induced between the ends of the rod.

Discussion

23.	Suppose all the electrons of 100 g water are lumped together to form a negatively hcarged particle and all the nuclei are lumped together to form a positively harged particle. If these two particles are plaed 10.0 cm away from each other, find the force of attraction between them. compare it with your weight.
Answer» Suppose all the electrons of 100 g water are lumped together to form a negatively hcarged particle and all the nuclei are lumped together to form a positively harged particle. If these two particles are plaed 10.0 cm away from each other, find the force of attraction between them. compare it with your weight.

Discussion

24.	What is Leyden jar?
Answer» What is Leyden jar?

Discussion

25.	Calculate the velocity of the centre of mass of the system of particulars shown in figure (9-E3).
Answer» Calculate the velocity of the centre of mass of the system of particulars shown in figure (9-E3).

25.

Calculate the velocity of the centre of mass of the system of particulars shown in figure (9-E3).

Answer»

Calculate the velocity of the centre of mass of the system of particulars shown in figure (9-E3).

Discussion

26.	A wheel of radius 1 m rolls forward half a revolution on a horizontal ground. The magnitude of the displacement of the point of the wheel initially in contact with the ground is
Answer» A wheel of radius $1 m$ rolls forward half a revolution on a horizontal ground. The magnitude of the displacement of the point of the wheel initially in contact with the ground is

Discussion

27.	The formula used to find the pressure on a swimmer h metres below the surface of a lake is: (where Pa is the atmospheric pressure.)
Answer» The formula used to find the pressure on a swimmer h metres below the surface of a lake is: (where P_a is the atmospheric pressure.)

Discussion

28.	The solubility of BaSO4 when CaSO4 and BaSO4 are dissolved in water simultaneously is: (KSP of CaSO4=P.KSP of BaSO4=q and simultaneous solubility of CaSO4 is ‘b’ mol/litre.)
Answer» The solubility of $B a S O_{4}$ when $C a S O_{4}$ and $B a S O_{4}$ are dissolved in water simultaneously is: $(K_{S P} o f C a S O_{4} = P . K_{S P}$ of $B a S O_{4} = q$ and simultaneous solubility of $C a S O_{4}$ is ‘b’ mol/litre.)

Discussion

29.	The friction coefficient between the horizontal surface and each of the blocks shown in figure (9-E20) is 0.20. The collision between the blocks is perfectly elastic. Find the separation between the two blocks when they come to rest. Take g−10 m/s2.
Answer» The friction coefficient between the horizontal surface and each of the blocks shown in figure (9-E20) is 0.20. The collision between the blocks is perfectly elastic. Find the separation between the two blocks when they come to rest. Take $g - 10 m / s^{2} .$

29.

The friction coefficient between the horizontal surface and each of the blocks shown in figure (9-E20) is 0.20. The collision between the blocks is perfectly elastic. Find the separation between the two blocks when they come to rest. Take g−10 m/s2.

Answer»

The friction coefficient between the horizontal surface and each of the blocks shown in figure (9-E20) is 0.20. The collision between the blocks is perfectly elastic. Find the separation between the two blocks when they come to rest. Take $g - 10 m / s^{2} .$

Discussion

30.	A spherical liquid drop is placed on a horizontal plane. A small disturbance causes the volume of the drop to oscillate. The time period of oscillation (T) of the liquid drop depends on radius (r) of the drop, density (ρ) and surface tension (S) of the liquid. Which among the following will be a possible expression for T (where k is a dimensionless constant)? (given surface tension is force per unit length)
Answer» A spherical liquid drop is placed on a horizontal plane. A small disturbance causes the volume of the drop to oscillate. The time period of oscillation $(T)$ of the liquid drop depends on radius $(r)$ of the drop, density $(ρ)$ and surface tension $(S)$ of the liquid. Which among the following will be a possible expression for $T$ (where $k$ is a dimensionless constant)? (given surface tension is force per unit length)

Discussion

31.	Four pieces of iron heated in a furnace to different temperatures show different colours listed below. Which one has the highest temperature
Answer» Four pieces of iron heated in a furnace to different temperatures show different colours listed below. Which one has the highest temperature

Discussion

32.	A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordinates. Two spheres of equal radii 1 unit with their centres at A(- 2, 0, 0) and B(2, 0, 0) respectively are taken out of the solid leaving behind spherical cavities as shown in figure. Then,
Answer» A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordinates. Two spheres of equal radii 1 unit with their centres at A(- 2, 0, 0) and B(2, 0, 0) respectively are taken out of the solid leaving behind spherical cavities as shown in figure. Then,

32.

A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordinates. Two spheres of equal radii 1 unit with their centres at A(- 2, 0, 0) and B(2, 0, 0) respectively are taken out of the solid leaving behind spherical cavities as shown in figure. Then,

Answer»

A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordinates. Two spheres of equal radii 1 unit with their centres at A(- 2, 0, 0) and B(2, 0, 0) respectively are taken out of the solid leaving behind spherical cavities as shown in figure. Then,

Discussion

33.	When a copper ball is heated, the largest percentage increase will occur in its:
Answer» When a copper ball is heated, the largest percentage increase will occur in its:

Discussion

34.	The block shown in the figure is just on the verge of slipping. The coefficient of static friction between the block and table is
Answer» The block shown in the figure is just on the verge of slipping. The coefficient of static friction between the block and table is

Discussion

35.	A car travels from A to B at a speed of 20 km/hr and returns at a speed of 30 km/hr. The average speed of the car for the whole journey is
Answer» A car travels from A to B at a speed of 20 km/hr and returns at a speed of 30 km/hr. The average speed of the car for the whole journey is

Discussion

36.	An open knife edge of mass m is dropped from a height h on a wooden floor. If the blade penetrates up to the depth d into the wood, the average resistance offered by the wood to the knife edge is
Answer» An open knife edge of mass $m$ is dropped from a height $h$ on a wooden floor. If the blade penetrates up to the depth $d$ into the wood, the average resistance offered by the wood to the knife edge is

Discussion

37.	Find the phase velocity of the wave whose y−x graph is shown at two instants.
Answer» Find the phase velocity of the wave whose $y - x$ graph is shown at two instants.

Discussion

38.	The conductivity of an intrinsic semiconductor depends on temperature as σ=σ0 e−ΔE/2KT, where σ0 is a constant. Find the temperature at which the conductivity of an intrinsic germanium semiconductor will be double of its value at T = 300 K. Assume that the gap for germanium is 0.650 eV and remains constant as the temperature is increased.
Answer» The conductivity of an intrinsic semiconductor depends on temperature as $σ = σ_{0} e^{- Δ E / 2 K T},$ where $σ_{0}$ is a constant. Find the temperature at which the conductivity of an intrinsic germanium semiconductor will be double of its value at T = 300 K. Assume that the gap for germanium is 0.650 eV and remains constant as the temperature is increased.

Discussion

39.	If a vector →P makes angles α, β and γ with X, Y and Z axes respectively. Then find sin2 α+sin2 β+sin2 γ
Answer» If a vector $\to P$ makes angles $α, β$ and $γ$ with X, Y and Z axes respectively. Then find $s i n^{2} α + s i n^{2} β + s i n^{2} γ$

Discussion

40.	A car has an initial velocity of 60 m/s. On application of brakes the car stops after 300 m. The retardation (deceleration) of the car is
Answer» A car has an initial velocity of $60 m/s$ . On application of brakes the car stops after $300 m$ . The retardation (deceleration) of the car is

Discussion

41.	Assume that a planet is rotating so fast that rocks at its surface are just starting to fly off from the surface at the equator. Assuming the density of the planet to be ρ and that the planet's material does not fly off, the time period of rotation must be
Answer» Assume that a planet is rotating so fast that rocks at its surface are just starting to fly off from the surface at the equator. Assuming the density of the planet to be $ρ$ and that the planet's material does not fly off, the time period of rotation must be

Discussion

42.	Fifth overtone of a closed pipe is found to be in unison with the third overtone of an open organ pipe. Find ratio of lengths of open organ pipe to that of closed organ pipe.
Answer» Fifth overtone of a closed pipe is found to be in unison with the third overtone of an open organ pipe. Find ratio of lengths of open organ pipe to that of closed organ pipe.

Discussion

43.	A uniform square wooden sheet of side a has its centre of mass located at point O as shown in the figure on the left. A square portion of side b of this sheet is cut out to produce and L- Shaped sheet as shown in the figure on the rightThe centre of mass of the L-shaped sheet lies at the point P (in the diagram) when
Answer» A uniform square wooden sheet of side a has its centre of mass located at point O as shown in the figure on the left. A square portion of side b of this sheet is cut out to produce and L- Shaped sheet as shown in the figure on the right The centre of mass of the L-shaped sheet lies at the point P (in the diagram) when

43.

A uniform square wooden sheet of side a has its centre of mass located at point O as shown in the figure on the left. A square portion of side b of this sheet is cut out to produce and L- Shaped sheet as shown in the figure on the rightThe centre of mass of the L-shaped sheet lies at the point P (in the diagram) when

Answer»

A uniform square wooden sheet of side a has its centre of mass located at point O as shown in the figure on the left. A square portion of side b of this sheet is cut out to produce and L- Shaped sheet as shown in the figure on the right

The centre of mass of the L-shaped sheet lies at the point P (in the diagram) when

Discussion

44.	Photoelectric effect experiments are performed using three different metal plates p, q and r having work functions Φp=2.0eV, Φq=2.5eV and Φr=3.0eV respectively. A light beam containing wavelengths of 550 nm, 450nm and 350nm with equal intensities illuminates each of the plates. The correct I - V graph for the experiment is : [Take hc = 1240 eV nm]
Answer» Photoelectric effect experiments are performed using three different metal plates p, q and r having work functions $Φ_{p} = 2.0 e V, Φ_{q} = 2.5 e V a n d Φ_{r} = 3.0 e V$ respectively. A light beam containing wavelengths of 550 nm, 450nm and 350nm with equal intensities illuminates each of the plates. The correct I - V graph for the experiment is : [Take hc = 1240 eV nm]

Discussion

45.	A body starts from orgin and moves along x-axis such that its velocity is v=(4t3−2t) m/s. Acceleration of particle when it is 2 m from origin is.
Answer» A body starts from orgin and moves along x-axis such that its velocity is $v = (4 t^{3} - 2 t)$ m/s. Acceleration of particle when it is 2 m from origin is.

Discussion

46.	A conical pendulum consists of a simple pendulum moving in a horizontal circle as shown in the figure. C is the pivot, O the centre of the circle in which the pendulum bob moves with a constant angular velocity ω . If ¯L is the angular momentum about point C, then
Answer» A conical pendulum consists of a simple pendulum moving in a horizontal circle as shown in the figure. C is the pivot, O the centre of the circle in which the pendulum bob moves with a constant angular velocity $ω$ . If $¯ L$ is the angular momentum about point C, then

46.

A conical pendulum consists of a simple pendulum moving in a horizontal circle as shown in the figure. C is the pivot, O the centre of the circle in which the pendulum bob moves with a constant angular velocity ω . If ¯L is the angular momentum about point C, then

Answer»

A conical pendulum consists of a simple pendulum moving in a horizontal circle as shown in the figure. C is the pivot, O the centre of the circle in which the pendulum bob moves with a constant angular velocity $ω$ . If $¯ L$ is the angular momentum about point C, then

Discussion

47.	In the far field diffraction pattern of a single slit under polychromatic illumination, the first minimum with the wavelength λ1 is found to be coincident with the third maximum at λ2. Then, which of the following equality is true?
Answer» In the far field diffraction pattern of a single slit under polychromatic illumination, the first minimum with the wavelength $λ_{1}$ is found to be coincident with the third maximum at $λ_{2}$ . Then, which of the following equality is true?

Discussion

48.	A particle is moving in a straight line. Its retardation is given as a=−(ln√2) v, here v is the speed of the particle in ms. The time (in s) in which speed of the particle reduces to half is .
Answer» A particle is moving in a straight line. Its retardation is given as $a = - (l n \sqrt{2}) v$ , here $v$ is the speed of the particle in $\frac{m}{s} .$ The time (in $s)$ in which speed of the particle reduces to half is .

Discussion

49.	There is an error of ± 0.04cm in the measurement of the diameter of a sphere. When the radius is 10cm,the percentage error in the volume of the sphere is
Answer» There is an error of $\pm$ 0.04cm in the measurement of the diameter of a sphere. When the radius is 10cm,the percentage error in the volume of the sphere is

Discussion

50.	Find the components of force F along and perpendicular to the incline if the direction of F is parallel to the horizontal axis.
Answer» Find the components of force $F$ along and perpendicular to the incline if the direction of $F$ is parallel to the horizontal axis.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Why Electric field lines are said to originate from positive charge?????

At what temperature the mean speed of the molecules of hydrogen gas equals the escape speed from the earth?

Which main standards are used in various functional areas?

Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional forces are 10% of energy. How much power is generated by the turbine?(g=10 m/s2)

A horizontal force of 10 N is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is 0.2. The weight of the block is

what does the term "unit time" refer to? is it one second?

If a body A of mass M is thrown with velocity V at an angle of 30∘ to the horizontal and another body B of the same mass is thrown with the same speed at an angle of 60∘ to the horizontal. The ratio of horizontal range of A to B will be

A body of density d1 is counterpoised by Mg of weights of density d2 in air of density d. Then the true mass of the body is

The time period of a second's pendulum is 2 sec. The spherical bob which is empty from inside has a mass of 50 gm. This is now replaced by another solid bob of same radius but having different mass of 100 gm. The new time period will be

If two conducting spheres are separately charged and then brought in contact, then

A uniform metal rod is used as a bar pendulum. If the room temperature rises by 10∘C, and the coefficient of linear expansion of the metal of the rod is 2 ´ 10−6per∘C , the period of the pendulum will have percentage increase of

A body of weight 50 N is dragged slowly with constant velocity on a horizontal surface as shown in the figure, with a force of F=28.2 N at an angle of 45∘ with horizontal. The net contact force acting on the body will be

The equation of a travelling wave is y = 60 cos (1800t – 6x) where y is in microns, t in seconds and x in metres. The ratio of maximum particle velocity to velocity of wave propagation is

Energy required to move a body of mass ‘m’ from an orbit of radius 2R to 3R is

A projectile is fired with some velocity making certain angle with the horizontal. Which of the following graphs is the best representation for the kinetic energy of a projectile (KE) versus its horizontal displacement (x)?

The magnetic field in a region is given by →B=→kB0Ly where L is a fixed length. A conducting rod of length L lies along the Y -axis between the origin and the point (0,L,0). IF the rod moves with a velocity v=v0→i, find the emf induced between the ends of the rod.

What is Leyden jar?

Calculate the velocity of the centre of mass of the system of particulars shown in figure (9-E3).

A wheel of radius 1 m rolls forward half a revolution on a horizontal ground. The magnitude of the displacement of the point of the wheel initially in contact with the ground is

The formula used to find the pressure on a swimmer h metres below the surface of a lake is: (where Pa is the atmospheric pressure.)

The solubility of BaSO4 when CaSO4 and BaSO4 are dissolved in water simultaneously is: (KSP of CaSO4=P.KSP of BaSO4=q and simultaneous solubility of CaSO4 is ‘b’ mol/litre.)

The friction coefficient between the horizontal surface and each of the blocks shown in figure (9-E20) is 0.20. The collision between the blocks is perfectly elastic. Find the separation between the two blocks when they come to rest. Take g−10 m/s2.

Four pieces of iron heated in a furnace to different temperatures show different colours listed below. Which one has the highest temperature

A solid sphere of uniform density and radius 4 units is located with its centre at the origin O of coordinates. Two spheres of equal radii 1 unit with their centres at A(- 2, 0, 0) and B(2, 0, 0) respectively are taken out of the solid leaving behind spherical cavities as shown in figure. Then,

When a copper ball is heated, the largest percentage increase will occur in its:

The block shown in the figure is just on the verge of slipping. The coefficient of static friction between the block and table is

A car travels from A to B at a speed of 20 km/hr and returns at a speed of 30 km/hr. The average speed of the car for the whole journey is

An open knife edge of mass m is dropped from a height h on a wooden floor. If the blade penetrates up to the depth d into the wood, the average resistance offered by the wood to the knife edge is

Find the phase velocity of the wave whose y−x graph is shown at two instants.

If a vector →P makes angles α, β and γ with X, Y and Z axes respectively. Then find sin2 α+sin2 β+sin2 γ

A car has an initial velocity of 60 m/s. On application of brakes the car stops after 300 m. The retardation (deceleration) of the car is

Assume that a planet is rotating so fast that rocks at its surface are just starting to fly off from the surface at the equator. Assuming the density of the planet to be ρ and that the planet's material does not fly off, the time period of rotation must be

Fifth overtone of a closed pipe is found to be in unison with the third overtone of an open organ pipe. Find ratio of lengths of open organ pipe to that of closed organ pipe.

A body starts from orgin and moves along x-axis such that its velocity is v=(4t3−2t) m/s. Acceleration of particle when it is 2 m from origin is.

A conical pendulum consists of a simple pendulum moving in a horizontal circle as shown in the figure. C is the pivot, O the centre of the circle in which the pendulum bob moves with a constant angular velocity ω . If ¯L is the angular momentum about point C, then

In the far field diffraction pattern of a single slit under polychromatic illumination, the first minimum with the wavelength λ1 is found to be coincident with the third maximum at λ2. Then, which of the following equality is true?

A particle is moving in a straight line. Its retardation is given as a=−(ln√2) v, here v is the speed of the particle in ms. The time (in s) in which speed of the particle reduces to half is .

There is an error of ± 0.04cm in the measurement of the diameter of a sphere. When the radius is 10cm,the percentage error in the volume of the sphere is

Find the components of force F along and perpendicular to the incline if the direction of F is parallel to the horizontal axis.