50278 + Interview Questions in Physics

1.	Two identical thin rings each of radius R metre are coaxially placed at a distance R metre apart Q1 and Q2 are respective charges uniformly spread on the two rings, calculate the work done in moving a charge q from the centre of one ring to that of other.
Answer» Two identical thin rings each of radius R metre are coaxially placed at a distance R metre apart Q1 and Q2 are respective charges uniformly spread on the two rings, calculate the work done in moving a charge q from the centre of one ring to that of other.

Discussion

2.	A machinist starts with three identical square plates but cuts one corner from one of them, two corners from the second and three comers from the third. Rank the three according to the x - coordinate of their of mass, from smallest to largest. Arrange in ascending order. For eg if the order is x1<x2<x3, answer is 123
Answer» A machinist starts with three identical square plates but cuts one corner from one of them, two corners from the second and three comers from the third. Rank the three according to the x - coordinate of their of mass, from smallest to largest. Arrange in ascending order. For eg if the order is $x_{1} < x_{2} < x_{3}$ , answer is 123

Discussion

3.	The angle of prism is 3∘. The refractive index is 1.5. The angle of minimum deviation is .
Answer» The angle of prism is $3^{\circ}$ . The refractive index is $1.5$ . The angle of minimum deviation is .

Discussion

4.	If a coil is moved from a magnetic field slowly and rapidly then in which case more work will be done
Answer» If a coil is moved from a magnetic field slowly and rapidly then in which case more work will be done

Discussion

5.	A body of mass 1 kg is subjected to a force of 20 N for 10 seconds after which the force ceases to act. What distance would it travel in the next 10 seconds? Assume that the body starts from rest.
Answer» A body of mass $1 k g$ is subjected to a force of $20 N$ for $10$ seconds after which the force ceases to act. What distance would it travel in the next $10$ seconds? Assume that the body starts from rest.

Discussion

6.	A disk of mass m and radius r rotates about an axis passing through its center and perpendicular to its plane with angular velocity ω. Find the percentage change in the kinetic energy when an identical disc is placed over the first disc and both the discs rotate about an axis passing through their center and perpendicular to the plane with same angular velocity ω. Assume there is no friction between the surfaces.
Answer» A disk of mass $m$ and radius $r$ rotates about an axis passing through its center and perpendicular to its plane with angular velocity $ω$ . Find the percentage change in the kinetic energy when an identical disc is placed over the first disc and both the discs rotate about an axis passing through their center and perpendicular to the plane with same angular velocity $ω$ . Assume there is no friction between the surfaces.

Discussion

7.	A 200 kg cannon at rest contains a 10 kg cannon ball. When fired, the cannon ball leaves the cannon with a speed of 90 m/s. What is the recoil speed of the cannon?
Answer» A $200 kg$ cannon at rest contains a $10 kg$ cannon ball. When fired, the cannon ball leaves the cannon with a speed of $90 m/s$ . What is the recoil speed of the cannon?

Discussion

8.	ddx(sin−1(cos x))=
Answer» $\frac{d}{d x} (s i n^{- 1} (c o s x)) =$

Discussion

9.	Balls of masses 4 kg and 10 kg are moving towards each other with speeds 6 m/s and 3 m/s respectively on a frictionless surface. After collision, the 4 kg ball is observed to return back (towards left) with speed 2 m/s. Find the velocity of 10 kg ball after collision.
Answer» Balls of masses $4 kg$ and $10 kg$ are moving towards each other with speeds $6 m/s$ and $3 m/s$ respectively on a frictionless surface. After collision, the $4 kg$ ball is observed to return back (towards left) with speed $2 m/s$ . Find the velocity of $10 kg$ ball after collision.

Discussion

10.	Span of a bridge at 10∘C is 2.4 km long. At 30 ∘C, the cable along the span sags by 0.5 km. Change in length of the cable when temperature changes from 10∘C to 42∘C is [ α=12×10−6/ ∘C ]
Answer» Span of a bridge at $10^{\circ} C$ is $2.4 km$ long. At $30^{\circ} C$ , the cable along the span sags by $0.5 km$ . Change in length of the cable when temperature changes from $10^{\circ} C$ to $42^{\circ} C$ is $[α = 12 \times 10^{- 6} /^{\circ} C]$

Discussion

11.	An adiabatic cylindrical chamber with a frictionless movable piston has been placed on a smooth horizontal surface as shown. One mole of an ideal monotonic gas is enclosed inside the chamber. Mass of the piston is M and mass of the remaining chamber including the gas is 4M. The gas is at atmospheric pressure and temperature. A particle of mass M moving horizontally with speed v, strikes the piston elastically. Find the change in temperature of the gas when the compression is maximum. [R is the ideal gas constant]
Answer» An adiabatic cylindrical chamber with a frictionless movable piston has been placed on a smooth horizontal surface as shown. One mole of an ideal monotonic gas is enclosed inside the chamber. Mass of the piston is $M$ and mass of the remaining chamber including the gas is $4 M$ . The gas is at atmospheric pressure and temperature. A particle of mass $M$ moving horizontally with speed $v$ , strikes the piston elastically. Find the change in temperature of the gas when the compression is maximum. [ $R$ is the ideal gas constant]

Discussion

12.	Which statement is true for a ball thrown at 20 degrees with the horizontal, when it is at the highest point in its trajectory?
Answer» Which statement is true for a ball thrown at 20 degrees with the horizontal, when it is at the highest point in its trajectory?

Discussion

13.	Assuming that the Earth is a uniform sphere with radius of 6400 km and atmospheric pressure on its surface to be 1 atm. With what force is it compressed by its atmosphere?
Answer» Assuming that the Earth is a uniform sphere with radius of 6400 km and atmospheric pressure on its surface to be 1 atm. With what force is it compressed by its atmosphere?

Discussion

14.	Which of the following are true for Planetary system in the solar system
Answer» Which of the following are true for Planetary system in the solar system

Discussion

15.	A plane mirror hinged at O is free to rotate in a vertical plane. The point O is at a distance x from a long screen placed in front of the mirror as shown in figure. A laser beam of light incident vertically downward is reflected by he mirror at O so that a bright spot is formed at the screen. At the instant shown, the angle of inclidence is θ and the mirror is rotating clockwise with constant angular velocity w. Find the speed of the spot at this instant.
Answer» A plane mirror hinged at O is free to rotate in a vertical plane. The point O is at a distance x from a long screen placed in front of the mirror as shown in figure. A laser beam of light incident vertically downward is reflected by he mirror at O so that a bright spot is formed at the screen. At the instant shown, the angle of inclidence is $θ$ and the mirror is rotating clockwise with constant angular velocity w. Find the speed of the spot at this instant.

Discussion

16.	Two blocks are connected by a string, as shown in figure. They are released from rest. The coefficient of kinetic friction between the upper block and the surface is 0.5. Assume that the pulley is massless and frictionless. Their common speed after they have moved a distance 5 m will be: (g=10 ms−2)
Answer» Two blocks are connected by a string, as shown in figure. They are released from rest. The coefficient of kinetic friction between the upper block and the surface is 0.5. Assume that the pulley is massless and frictionless. Their common speed after they have moved a distance $5 m$ will be: ( $g = 10 m s^{- 2}$ )

Discussion

17.	Two blocks of masses 1 kg and 2 kg are connected by a metal wire going over a smooth pulley as shown in the figure. The breaking stress of the metal is (40/3π)×106 N/m2. If g=10 m/s2, then what should be the minimum radius of the wire used if it is not to break?
Answer» Two blocks of masses $1 kg$ and $2 kg$ are connected by a metal wire going over a smooth pulley as shown in the figure. The breaking stress of the metal is $(40 / 3 π) \times 10^{6} {N/m}^{2}$ . If $g = 10 {m/s}^{2}$ , then what should be the minimum radius of the wire used if it is not to break?

Discussion

18.	A block of mass 2 kg lying on another block of mass 5 kg the whole system moves upward with acceleration 5 m/s² . Find the force exerted by 5 kg block on the floor.
Answer» A block of mass 2 kg lying on another block of mass 5 kg the whole system moves upward with acceleration 5 m/s² . Find the force exerted by 5 kg block on the floor.

Discussion

19.	State two ways by which electrons can be made to leave the metal surface.
Answer» State two ways by which electrons can be made to leave the metal surface.

Discussion

20.	The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle α should be
Answer» The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle $α$ should be

Discussion

21.	A wheel completes 2000 revolutions which is equivalent to a linear distance of 9.5 km distance, then the diameter of the wheel is
Answer» A wheel completes $2000$ revolutions which is equivalent to a linear distance of $9.5 k m$ distance, then the diameter of the wheel is

Discussion

22.	From a given sample of uniform wire, two circular loops P and Q are made, P of radius r and Q of radius nr. If the M.I. of Q about its axis is four times that of P about its axis. If n is x1/3, then x is:
Answer» From a given sample of uniform wire, two circular loops P and Q are made, P of radius r and Q of radius nr. If the M.I. of Q about its axis is four times that of P about its axis. If $n$ is $x^{1 / 3}$ , then $x$ is:

Discussion

23.	If the radius of the earth were increased by a factor of 2 keeping the mass constant by what factor would its density have to be changed to keep g the same?
Answer» If the radius of the earth were increased by a factor of 2 keeping the mass constant by what factor would its density have to be changed to keep g the same?

Discussion

24.	A small sphere of mass m is connected by a string to a nail at O and moves in a circle of radius r on the smooth plane inclined at an angle of θ with the horizontal. If the sphere moves with minimum velocity at A such that string does not get slack, then what will be the tension in the string when it passes through point C?
Answer» A small sphere of mass $m$ is connected by a string to a nail at $O$ and moves in a circle of radius $r$ on the smooth plane inclined at an angle of $θ$ with the horizontal. If the sphere moves with minimum velocity at A such that string does not get slack, then what will be the tension in the string when it passes through point C?

Discussion

25.	Find the moment of inertia of the system about the axis passing through the COM and perpendicular to its plane. All eight particles have the same mass M and located at distances R and 2R from the centre O, as shown in figure.
Answer» Find the moment of inertia of the system about the axis passing through the $C O M$ and perpendicular to its plane. All eight particles have the same mass $M$ and located at distances $R$ and $2 R$ from the centre $O$ , as shown in figure.

Discussion

26.	Why electric current doesn't obey traingle rule of addition even though it has magnitude and direction
Answer» Why electric current doesn't obey traingle rule of addition even though it has magnitude and direction

Discussion

27.	Q. Eight identical spherical drops, each carrying a charge 1 nC are at a potential of 900 V each. All these drops combine together to form a single large drop. Calculate the potential of this large drop. (Assume no wastage of any kind and take the capacitance of a sphere of radius r as proportional to r).
Answer» Q. Eight identical spherical drops, each carrying a charge 1 nC are at a potential of 900 V each. All these drops combine together to form a single large drop. Calculate the potential of this large drop. (Assume no wastage of any kind and take the capacitance of a sphere of radius r as proportional to r).

Discussion

28.	A clock S is based on oscillation of a spring and a clock P is based on pendulum motion. Both clocks run at the same rate on earth. On a planet having the same density as earth but twice the radius
Answer» A clock S is based on oscillation of a spring and a clock P is based on pendulum motion. Both clocks run at the same rate on earth. On a planet having the same density as earth but twice the radius

Discussion

29.	A wire suspended vertically from one of its ends is stretched by attaching a weight of 200 N to its lower end. If the weight stretches the wire by 1 mm, then elastic energy stored in the wire is
Answer» A wire suspended vertically from one of its ends is stretched by attaching a weight of $200 N$ to its lower end. If the weight stretches the wire by $1 mm$ , then elastic energy stored in the wire is

Discussion

30.	Find the unit vector in the direction of the vector a=^i+^j+2^k.
Answer» Find the unit vector in the direction of the vector $a =^i +^j + 2^k .$

Discussion

31.	Velocity of a boat in still water is 13 m/s. If the water in a river flows with a velocity of 5 m/s and the width of the river is 156 m, what is the difference in time taken by the boat to cross the river in the shortest possible path and the shortest possible time? (in seconds)
Answer» Velocity of a boat in still water is $13 m / s$ . If the water in a river flows with a velocity of $5 m / s$ and the width of the river is $156 m$ , what is the difference in time taken by the boat to cross the river in the shortest possible path and the shortest possible time? (in seconds)

Discussion

32.	A force F=−K(yi+aj) (where K is a positive constant) acts on a particle moving in the xy-plane. Starting from the origin, the particle is taken along the positive x-axis to the point (a, 0) and then parallel to the y-axis to the point (a, a). The total work done by the force F on the particles is
Answer» A force F=−K(yi+aj) (where K is a positive constant) acts on a particle moving in the xy-plane. Starting from the origin, the particle is taken along the positive x-axis to the point (a, 0) and then parallel to the y-axis to the point (a, a). The total work done by the force F on the particles is

Discussion

33.	Electric field is restricted to a circular area of diameter 20 cm as shown in figure. Magnitude of electric field is increasing at a rate of 200 V/(m−s), then magnitude of magnetic field at a point 20 cm from the center of circle is
Answer» Electric field is restricted to a circular area of diameter $20 c m$ as shown in figure. Magnitude of electric field is increasing at a rate of $200 V / (m - s)$ , then magnitude of magnetic field at a point $20 c m$ from the center of circle is

Discussion

34.	A circular race-car track of radius 300 m is banked at an angle of 15∘. If the coefficient of static friction between the wheels of the race-car and the road is 0.2, what is the maximum permissible speed to avoid slipping? Take tan15∘=0.27, g=10 m/s2.
Answer» A circular race-car track of radius $300 m$ is banked at an angle of $15^{\circ}$ . If the coefficient of static friction between the wheels of the race-car and the road is $0.2$ , what is the maximum permissible speed to avoid slipping? Take $tan 15^{\circ} = 0.27, g = 10 {m/s}^{2}$ .

Discussion

35.	The coefficient of friction between a body and the surface of an inclined plane at 45o is 0.5. If g=9.8 m/s2 the acceleration of the body downwards in m/s2 is
Answer» The coefficient of friction between a body and the surface of an inclined plane at $45^{o}$ is 0.5. If g=9.8 $m / s^{2}$ the acceleration of the body downwards in $m / s^{2}$ is

Discussion

36.	(a) Draw a schematic sketch of a cyclotron. Explain clearly the role of crossed electric and magnetic field in accelerating the charge. Hence derive the expression for the kinetic energy acquired by the particles. (b) An α-particle and a photon are released from the centre of the cyclotron and made to accelerate. (i) Can both be accelerated at the same cyclotron frequency ? Give reason to justify your answer. (ii) When they are accelerated in turn, which of the two will have higher velocity at the exit slit of the dees ?
Answer» (a) Draw a schematic sketch of a cyclotron. Explain clearly the role of crossed electric and magnetic field in accelerating the charge. Hence derive the expression for the kinetic energy acquired by the particles. (b) An $α$ -particle and a photon are released from the centre of the cyclotron and made to accelerate. (i) Can both be accelerated at the same cyclotron frequency ? Give reason to justify your answer. (ii) When they are accelerated in turn, which of the two will have higher velocity at the exit slit of the dees ?

Discussion

37.	A sinusoidal wave travelling in the positive direction on stretched string has amplitude 2.0 cm, wavelength 1.0 m and wave velocity 5.0 m/s. At x = 0 and t = 0 it is given that y = 0 and δyδt<0. Find the wave function y(x, t).
Answer» A sinusoidal wave travelling in the positive direction on stretched string has amplitude 2.0 cm, wavelength 1.0 m and wave velocity 5.0 m/s. At x = 0 and t = 0 it is given that y = 0 and $\frac{δ y}{δ t} < 0$ . Find the wave function y(x, t).

Discussion

38.	A fully charged capacitor has a capacitance C. It is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity s and mass m. If the temperature of the block is raised by Δ T, the potential difference V across the capacitance was?
Answer» A fully charged capacitor has a capacitance C. It is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity s and mass m. If the temperature of the block is raised by $Δ$ T, the potential difference V across the capacitance was?

Discussion

39.	Every series of hydrogen spectrum has an upper and lower limit in wavelength. The spectral series which has an upper limit of wavelength equal to 18752 ∘A is
Answer» Every series of hydrogen spectrum has an upper and lower limit in wavelength. The spectral series which has an upper limit of wavelength equal to $18752 \circ A$ is

Discussion

40.	Derive formula for the time period of projectile motion.
Answer» Derive formula for the time period of projectile motion.

Discussion

41.	A 100 Ω resistance and a capacitor of 100 Ω reactance are connected in series across a 220 V source. When the capacitor is 50% charged, the peak value of the displacement current is
Answer» A $100 Ω$ resistance and a capacitor of $100 Ω$ reactance are connected in series across a $220 V$ source. When the capacitor is $50 %$ charged, the peak value of the displacement current is

Discussion

42.	Energy of H-atom in the ground state is –13.6 eV, the energy of electron in the second excited state
Answer» Energy of H-atom in the ground state is –13.6 eV, the energy of electron in the second excited state

Discussion

43.	Two identical travelling waves, moving in the same direction, are out of phase by π2 rad. If amplitude of each wave is A, then find the resultant amplitude of the wave after superimposition.
Answer» Two identical travelling waves, moving in the same direction, are out of phase by $\frac{π}{2} rad$ . If amplitude of each wave is $A$ , then find the resultant amplitude of the wave after superimposition.

Discussion

44.	A man who cannot see clearly beyond 5 m wants to see stars clearly. He should use a lens of focal length [MP PET/PMT 1988; Pb. PET 2003]
Answer» A man who cannot see clearly beyond 5 m wants to see stars clearly. He should use a lens of focal length [MP PET/PMT 1988; Pb. PET 2003]

44.

A man who cannot see clearly beyond 5 m wants to see stars clearly. He should use a lens of focal length [MP PET/PMT 1988; Pb. PET 2003]

Answer»

A man who cannot see clearly beyond 5 m wants to see stars clearly. He should use a lens of focal length

[MP PET/PMT 1988; Pb. PET 2003]

Discussion

45.	A uniformly charged thin spherical shell of radius R carries uniform surface charge density of σ per unit area. It is made of two hemispherical shells, held together by pressing them with force F. F is proportional to :
Answer» A uniformly charged thin spherical shell of radius $R$ carries uniform surface charge density of σ per unit area. It is made of two hemispherical shells, held together by pressing them with force $F$ . $F$ is proportional to :

Discussion

46.	If the ratio of intensities of two waves is 1 : 25, then the ratio of their amplitudes will be
Answer» If the ratio of intensities of two waves is 1 : 25, then the ratio of their amplitudes will be

Discussion

47.	The average depth of Indian Ocean is about 3000 m. The fractional compression, ΔVVof water at the bottom of the ocean (given that the bulk modulus of the water =2.2×109Nm−2 and g=10 ms−2, assuming density of water remains constant) is
Answer» The average depth of Indian Ocean is about $3000 m$ . The fractional compression, $\frac{Δ V}{V}$ of water at the bottom of the ocean (given that the bulk modulus of the water = $2.2 \times 10^{9} {Nm}^{- 2} {and g=10 ms}^{- 2}$ , assuming density of water remains constant) is

Discussion

48.	Two sinusoidal sound waves were generated from same source after a time gap of 2 sec what is the phase difference between them if their time period is 10s.
Answer» Two sinusoidal sound waves were generated from same source after a time gap of 2 sec what is the phase difference between them if their time period is 10s.

Discussion

49.	If the system shown in the figure is at rest initially, find the common acceleration of the two block system? (Take g=10 m/s2)
Answer» If the system shown in the figure is at rest initially, find the common acceleration of the two block system? (Take $g = 10 m / s^{2}$ )

Discussion

50.	A particle is projected vertically upward from the surface of the earth with a speed of √32gR, R being the radius of the earth and g is the acceleration due to gravity on the surface of the earth. Then the maximum height ascended is (neglect cosmic dust resistance)
Answer» A particle is projected vertically upward from the surface of the earth with a speed of $\sqrt{\frac{3}{2} g R}$ , $R$ being the radius of the earth and g is the acceleration due to gravity on the surface of the earth. Then the maximum height ascended is (neglect cosmic dust resistance)

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Two identical thin rings each of radius R metre are coaxially placed at a distance R metre apart Q1 and Q2 are respective charges uniformly spread on the two rings, calculate the work done in moving a charge q from the centre of one ring to that of other.

The angle of prism is 3∘. The refractive index is 1.5. The angle of minimum deviation is .

If a coil is moved from a magnetic field slowly and rapidly then in which case more work will be done

A body of mass 1 kg is subjected to a force of 20 N for 10 seconds after which the force ceases to act. What distance would it travel in the next 10 seconds? Assume that the body starts from rest.

A 200 kg cannon at rest contains a 10 kg cannon ball. When fired, the cannon ball leaves the cannon with a speed of 90 m/s. What is the recoil speed of the cannon?

ddx(sin−1(cos x))=

Balls of masses 4 kg and 10 kg are moving towards each other with speeds 6 m/s and 3 m/s respectively on a frictionless surface. After collision, the 4 kg ball is observed to return back (towards left) with speed 2 m/s. Find the velocity of 10 kg ball after collision.

Span of a bridge at 10∘C is 2.4 km long. At 30 ∘C, the cable along the span sags by 0.5 km. Change in length of the cable when temperature changes from 10∘C to 42∘C is [ α=12×10−6/ ∘C ]

Which statement is true for a ball thrown at 20 degrees with the horizontal, when it is at the highest point in its trajectory?

Assuming that the Earth is a uniform sphere with radius of 6400 km and atmospheric pressure on its surface to be 1 atm. With what force is it compressed by its atmosphere?

Which of the following are true for Planetary system in the solar system

Two blocks of masses 1 kg and 2 kg are connected by a metal wire going over a smooth pulley as shown in the figure. The breaking stress of the metal is (40/3π)×106 N/m2. If g=10 m/s2, then what should be the minimum radius of the wire used if it is not to break?

A block of mass 2 kg lying on another block of mass 5 kg the whole system moves upward with acceleration 5 m/s² . Find the force exerted by 5 kg block on the floor.

State two ways by which electrons can be made to leave the metal surface.

The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle α should be

A wheel completes 2000 revolutions which is equivalent to a linear distance of 9.5 km distance, then the diameter of the wheel is

From a given sample of uniform wire, two circular loops P and Q are made, P of radius r and Q of radius nr. If the M.I. of Q about its axis is four times that of P about its axis. If n is x1/3, then x is:

If the radius of the earth were increased by a factor of 2 keeping the mass constant by what factor would its density have to be changed to keep g the same?

Find the moment of inertia of the system about the axis passing through the COM and perpendicular to its plane. All eight particles have the same mass M and located at distances R and 2R from the centre O, as shown in figure.

Why electric current doesn't obey traingle rule of addition even though it has magnitude and direction

A clock S is based on oscillation of a spring and a clock P is based on pendulum motion. Both clocks run at the same rate on earth. On a planet having the same density as earth but twice the radius

A wire suspended vertically from one of its ends is stretched by attaching a weight of 200 N to its lower end. If the weight stretches the wire by 1 mm, then elastic energy stored in the wire is

Find the unit vector in the direction of the vector a=^i+^j+2^k.

Velocity of a boat in still water is 13 m/s. If the water in a river flows with a velocity of 5 m/s and the width of the river is 156 m, what is the difference in time taken by the boat to cross the river in the shortest possible path and the shortest possible time? (in seconds)

A force F=−K(yi+aj) (where K is a positive constant) acts on a particle moving in the xy-plane. Starting from the origin, the particle is taken along the positive x-axis to the point (a, 0) and then parallel to the y-axis to the point (a, a). The total work done by the force F on the particles is

Electric field is restricted to a circular area of diameter 20 cm as shown in figure. Magnitude of electric field is increasing at a rate of 200 V/(m−s), then magnitude of magnetic field at a point 20 cm from the center of circle is

A circular race-car track of radius 300 m is banked at an angle of 15∘. If the coefficient of static friction between the wheels of the race-car and the road is 0.2, what is the maximum permissible speed to avoid slipping? Take tan15∘=0.27, g=10 m/s2.

The coefficient of friction between a body and the surface of an inclined plane at 45o is 0.5. If g=9.8 m/s2 the acceleration of the body downwards in m/s2 is

A sinusoidal wave travelling in the positive direction on stretched string has amplitude 2.0 cm, wavelength 1.0 m and wave velocity 5.0 m/s. At x = 0 and t = 0 it is given that y = 0 and δyδt&lt;0. Find the wave function y(x, t).

A fully charged capacitor has a capacitance C. It is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity s and mass m. If the temperature of the block is raised by Δ T, the potential difference V across the capacitance was?

Every series of hydrogen spectrum has an upper and lower limit in wavelength. The spectral series which has an upper limit of wavelength equal to 18752 ∘A is

Derive formula for the time period of projectile motion.

A 100 Ω resistance and a capacitor of 100 Ω reactance are connected in series across a 220 V source. When the capacitor is 50% charged, the peak value of the displacement current is

Energy of H-atom in the ground state is –13.6 eV, the energy of electron in the second excited state

Two identical travelling waves, moving in the same direction, are out of phase by π2 rad. If amplitude of each wave is A, then find the resultant amplitude of the wave after superimposition.

A man who cannot see clearly beyond 5 m wants to see stars clearly. He should use a lens of focal length [MP PET/PMT 1988; Pb. PET 2003]

A uniformly charged thin spherical shell of radius R carries uniform surface charge density of σ per unit area. It is made of two hemispherical shells, held together by pressing them with force F. F is proportional to :

If the ratio of intensities of two waves is 1 : 25, then the ratio of their amplitudes will be

The average depth of Indian Ocean is about 3000 m. The fractional compression, ΔVVof water at the bottom of the ocean (given that the bulk modulus of the water =2.2×109Nm−2 and g=10 ms−2, assuming density of water remains constant) is

Two sinusoidal sound waves were generated from same source after a time gap of 2 sec what is the phase difference between them if their time period is 10s.

If the system shown in the figure is at rest initially, find the common acceleration of the two block system? (Take g=10 m/s2)

A particle is projected vertically upward from the surface of the earth with a speed of √32gR, R being the radius of the earth and g is the acceleration due to gravity on the surface of the earth. Then the maximum height ascended is (neglect cosmic dust resistance)

A sinusoidal wave travelling in the positive direction on stretched string has amplitude 2.0 cm, wavelength 1.0 m and wave velocity 5.0 m/s. At x = 0 and t = 0 it is given that y = 0 and δyδt<0. Find the wave function y(x, t).