50278 + Interview Questions in Physics

1.	In the given circuit, charge Q2 on the 2 μF capacitor changes as C is varied from 1 μF to 3 μF. Q2 as a function of C is given properly by(figures are drawn schematically and not to scale)
Answer» In the given circuit, charge $Q_{2}$ on the $2 μ F$ capacitor changes as $C$ is varied from $1 μ F$ to $3 μ F$ . $Q_{2}$ as a function of $C$ is given properly by (figures are drawn schematically and not to scale)

Discussion

2.	The introduction of a metal plate between the plates of a parallel plate capacitor increases its capacitance by 4.5 times. If d is the separation of the two plates of the capacitor, the thickness of the metal plate introduced is
Answer» The introduction of a metal plate between the plates of a parallel plate capacitor increases its capacitance by 4.5 times. If d is the separation of the two plates of the capacitor, the thickness of the metal plate introduced is

Discussion

3.	A circular disc rolls down an inclined plane without slipping. What fraction of its total energy is translational energy?
Answer» A circular disc rolls down an inclined plane without slipping. What fraction of its total energy is translational energy?

Discussion

4.	Two bulbs are marked as ‘A’ having rating 60W, 220V & ‘B’ having rating 100W, 220V. They are connected in parallel to a 220 V source. Which of the two will glow brighter?
Answer» Two bulbs are marked as ‘A’ having rating 60W, 220V & ‘B’ having rating 100W, 220V. They are connected in parallel to a 220 V source. Which of the two will glow brighter?

Discussion

5.	what happens when high pressure is applied on ice? 1) it melts 2) it attains equilibrium 3) it remaims same 4) nome of these
Answer» what happens when high pressure is applied on ice? 1) it melts 2) it attains equilibrium 3) it remaims same 4) nome of these

Discussion

6.	A thermally insulated rigid container contains an ideal gas at 27oC. It is fitted with a heating coil of resistance 50Ω. A current is passed through the coil for 10 minutes by connecting it to a d.c. source of 10 V. The change in the internal energy is
Answer» A thermally insulated rigid container contains an ideal gas at $27^{o} C$ . It is fitted with a heating coil of resistance 50 $Ω$ . A current is passed through the coil for 10 minutes by connecting it to a d.c. source of 10 V. The change in the internal energy is

Discussion

7.	A simple harmonic oscillator has a period of 0.01 sec and an amplitude of 0.2 m. The magnitude of the velocity in m sec−1 at the centre of oscillation is [JIPMER 1997]
Answer» A simple harmonic oscillator has a period of 0.01 sec and an amplitude of 0.2 m. The magnitude of the velocity in $m s e c^{- 1}$ at the centre of oscillation is [JIPMER 1997]

7.

A simple harmonic oscillator has a period of 0.01 sec and an amplitude of 0.2 m. The magnitude of the velocity in m sec−1 at the centre of oscillation is [JIPMER 1997]

Answer»

A simple harmonic oscillator has a period of 0.01 sec and an amplitude of 0.2 m. The magnitude of the velocity in $m s e c^{- 1}$ at the centre of oscillation is

[JIPMER 1997]

Discussion

8.	The position of the particle is given by x=t2−4t+6 in m. The average speed of the particle in 5 sec is
Answer» The position of the particle is given by $x = t^{2} - 4 t + 6$ in $m$ . The average speed of the particle in $5 sec$ is

Discussion

9.	A ball of mass 300 gram falls on an elevator moving up with a uniform velocity of 10 m/s. It hits the floor of elevator with speed of 15 m/s and suffers elastic collision. What will be rebounding speed of the ball from elevator floor?
Answer» A ball of mass 300 gram falls on an elevator moving up with a uniform velocity of 10 m/s. It hits the floor of elevator with speed of 15 m/s and suffers elastic collision. What will be rebounding speed of the ball from elevator floor?

Discussion

10.	Why does the position of other bands except bright fringe in the centre, depends on the wavelength in the diffraction??
Answer» Why does the position of other bands except bright fringe in the centre, depends on the wavelength in the diffraction??

Discussion

11.	Consider a car moving along a straight horizontal road with a speed of 72 km/h. If the coefficient of kinetic friction between the tyres and the road is 0.5, the shortest distance in which the car can be stopped is [g=10 m/s−2]
Answer» Consider a car moving along a straight horizontal road with a speed of 72 km/h. If the coefficient of kinetic friction between the tyres and the road is 0.5, the shortest distance in which the car can be stopped is $[g = 10 m / s^{- 2}]$

Discussion

12.	A point charge q exerts an electric force on a second point charge q2. If third charge q3 is brought near, the electric force of q1 exerted on q2 will? a)increase b)decrease c)remains unchanged d) increases if q3 is of same origin and decreases if q3 is of opposite orig
Answer» A point charge q exerts an electric force on a second point charge q2. If third charge q3 is brought near, the electric force of q1 exerted on q2 will? a)increase b)decrease c)remains unchanged d) increases if q3 is of same origin and decreases if q3 is of opposite orig

Discussion

13.	A block of mass 10 kg is slowly moved up on a smooth inclined plane of inclination θ by a person. Work done by the person to move the block through a distance of 2 m is 120 J. If force is applied in horizontal direction. Find out inclination angle θ. (Take g=10 m/s2)
Answer» A block of mass $10 kg$ is slowly moved up on a smooth inclined plane of inclination $θ$ by a person. Work done by the person to move the block through a distance of $2 m$ is $120 J$ . If force is applied in horizontal direction. Find out inclination angle $θ$ . (Take $g = 10 m / s^{2}$ )

Discussion

14.	A body is projected with speed 55m/s vertically upwards. The distance travelled by the body in time interval 4s to 8s?
Answer» A body is projected with speed 55m/s vertically upwards. The distance travelled by the body in time interval 4s to 8s?

Discussion

15.	A star 2.5 times themass of the sun and collapsed to a size of 12 km rotates with a speedof 1.2 rev. per second. (Extremely compact stars of this kind areknown as neutron stars. Certain stellar objects called pulsars belongto this category). Will an object placed on its equator remain stuckto its surface due to gravity? (Mass of the sun = 2 × 1030kg).
Answer» A star 2.5 times the mass of the sun and collapsed to a size of 12 km rotates with a speed of 1.2 rev. per second. (Extremely compact stars of this kind are known as neutron stars. Certain stellar objects called pulsars belong to this category). Will an object placed on its equator remain stuck to its surface due to gravity? (Mass of the sun = 2 × 10³⁰ kg).

Discussion

16.	A boat moves relative to water with a velocity which is 2.0 times than the river flow velocity. At what angle to the stream direction must the boat move to minimise drifting?
Answer» A boat moves relative to water with a velocity which is 2.0 times than the river flow velocity. At what angle to the stream direction must the boat move to minimise drifting?

Discussion

17.	16. A solid cylinder rolls down an inclined plane of height 3 m and reaches the bottom of plane with angular velocity of2\sqrt2 rad/s The radius of cylinder must be \lbrack Take g = 10ms2\rbrack
Answer» 16. A solid cylinder rolls down an inclined plane of height 3 m and reaches the bottom of plane with angular velocity of2\sqrt2 rad/s The radius of cylinder must be \lbrack Take g = 10ms2\rbrack

Discussion

18.	A stone falls freely under gravity, covers distance h1,h2 and h3 in the first 5 sec, the next 5 sec and the further next 5 sec respectively. The relation between h1,h2 and h3 is:
Answer» A stone falls freely under gravity, covers distance $h_{1}, h_{2}$ and $h_{3}$ in the first 5 sec, the next 5 sec and the further next 5 sec respectively. The relation between $h_{1}, h_{2}$ and $h_{3}$ is:

Discussion

19.	For the 4-bus system, containing transmission lines and transformers. The admittance matrix is Ybus=⎡⎢⎢⎢⎢⎣−j20j2000j20−j60j4000j40−j60j2000j20−j25⎤⎥⎥⎥⎥⎦If a transmission line having π-equivalent circuit as shown below is connected between 2nd and 4th buses. Then the modified Ybus matrix will be Where, Zse = series impedance of transmission line.Ysh= shunt admittance of transmission line.
Answer» For the 4-bus system, containing transmission lines and transformers. The admittance matrix is $Y_{b u s} = ⎡ ⎢⎢⎢⎢ ⎣ \begin{matrix} - j 20 & j 20 & 0 & 0 j 20 & - j 60 & j 40 & 0 0 & j 40 & - j 60 & j 20 0 & 0 & j 20 & - j 25 \end{matrix} ⎤ ⎥⎥⎥⎥ ⎦$ If a transmission line having $π$ -equivalent circuit as shown below is connected between $2^{n d}$ and $4^{t h}$ buses. Then the modified $Y_{b u s}$ matrix will be Where, $Z_{s e}$ = series impedance of transmission line. $Y_{s h} =$ shunt admittance of transmission line.

Discussion

20.	Two transparent media of refractive indices μ1 and μ3 have a solid lens shaped transparent media of refractive index μ2 between them as shown in figure.The correct relation between refractive indices is:
Answer» Two transparent media of refractive indices $μ_{1}$ and $μ_{3}$ have a solid lens shaped transparent media of refractive index $μ_{2}$ between them as shown in figure. The correct relation between refractive indices is:

Discussion

21.	The diagram shows a capacitor C and a resistor R connected in series to an ac source. V1 and V2 are voltmeters and A is an ammeter Consider now the following statements 1) Readings in A and V2 are always in phase 2) Reading in V1 is ahead in phase with reading in V2 3) Readings in A and V1 are always in phase which of these statements are / is correct
Answer» The diagram shows a capacitor C and a resistor R connected in series to an ac source. $V_{1}$ and $V_{2}$ are voltmeters and A is an ammeter Consider now the following statements 1) Readings in A and $V_{2}$ are always in phase 2) Reading in $V_{1}$ is ahead in phase with reading in $V_{2}$ 3) Readings in A and $V_{1}$ are always in phase which of these statements are / is correct

Discussion

22.	A longitudinal wave propagating in a water-filled pipe has intensity 3.00 × 10−6 wm2 and frequency 3400 Hz. Water has density 1000 kgm3 and bulk modulus 2.18 × 109 Pa. If the pipe is then filled with air at pressure 1.00 × 105 Pa and density 1.20 kgm3, and the a wave with the same intensity and frequency is propagated, What is the ratio of the two amplitudes in both media?
Answer» A longitudinal wave propagating in a water-filled pipe has intensity $3.00 \times 10^{- 6} \frac{w}{m^{2}}$ and frequency 3400 Hz. Water has density $1000 \frac{k g}{m^{3}}$ and bulk modulus $2.18 \times 10^{9}$ Pa. If the pipe is then filled with air at pressure $1.00 \times 10^{5}$ Pa and density $1.20 \frac{k g}{m^{3}}$ , and the a wave with the same intensity and frequency is propagated, What is the ratio of the two amplitudes in both media?

Discussion

23.	The ratio of time constants during current growth and current decay of the circuit shown in figure is k:2, then k=___
Answer» The ratio of time constants during current growth and current decay of the circuit shown in figure is k:2, then k=___

Discussion

24.	In new system , the force between the masses given by F directly proportional to r^2 , then time period of revolution T is proportional to
Answer» In new system , the force between the masses given by F directly proportional to r^2 , then time period of revolution T is proportional to

Discussion

25.	The charge on a conductor is positive Q and its potential is V(i.e. the electric potential on its surface)If some more positive charge is added to it, what are the possible values of its new potential?
Answer» The charge on a conductor is positive Q and its potential is V (i.e. the electric potential on its surface) If some more positive charge is added to it, what are the possible values of its new potential?

Discussion

26.	A wide vessel with a small hole at the bottom is filled with water and kerosene. Find the approximate velocity of the water flow if thickness of water layer is 30 cm and that of kerosene layer is 20 cm.Specific gravity of kerosene =0.8.
Answer» A wide vessel with a small hole at the bottom is filled with water and kerosene. Find the approximate velocity of the water flow if thickness of water layer is $30 cm$ and that of kerosene layer is $20 cm$ . Specific gravity of kerosene $= 0.8$ .

Discussion

27.	The figure shows a spherical capacitor with inner sphere earthed. If a=2 cm and b=3 cm, then the capacitance of the system is(Take k=9×109 Nm2/C2)
Answer» The figure shows a spherical capacitor with inner sphere earthed. If $a = 2 cm$ and $b = 3 cm$ , then the capacitance of the system is (Take $k = 9 \times 10^{9} {Nm}^{2} / C^{2}$ )

Discussion

28.	Thethreshold frequency for a certain metal is 3.3 × 1014Hz. If light of frequency 8.2 ×1014Hz is incident on the metal, predict the cutoff voltage for thephotoelectric emission.
Answer» The threshold frequency for a certain metal is 3.3 × 10¹⁴Hz. If light of frequency 8.2 × 10¹⁴ Hz is incident on the metal, predict the cutoff voltage for the photoelectric emission.

Discussion

29.	A fully charged capacitor C with initial charge q0 is connected to a coil of inductance L at time t = 0. The time after which the energy is stored equally between electric and magnetic fields is
Answer» A fully charged capacitor C with initial charge q₀ is connected to a coil of inductance L at time t = 0. The time after which the energy is stored equally between electric and magnetic fields is

Discussion

30.	Four rods of identical cross-sectional area and made from the same metal form the sides of square. The temperature of two diagonally opposite points is T and √2 T respective in the steady state. Assuming that only heat conduction takes place, what will be the temperature difference between other two points
Answer» Four rods of identical cross-sectional area and made from the same metal form the sides of square. The temperature of two diagonally opposite points is T and $\sqrt{2}$ T respective in the steady state. Assuming that only heat conduction takes place, what will be the temperature difference between other two points

Discussion

31.	Two particles A and B are moving in opposite direction on a circle. Initially particle A and B are diagonally opposite to each other. Particle A move with angular velocity π rad/s, angular acceleration π2 rad/s2 and particle B moves with constant angular velocity 2π rad/s. Find the time after which both the particles A and B will collide.
Answer» Two particles $A$ and $B$ are moving in opposite direction on a circle. Initially particle $A$ and $B$ are diagonally opposite to each other. Particle $A$ move with angular velocity $π rad/s$ , angular acceleration $\frac{π}{2} {rad/s}^{2}$ and particle $B$ moves with constant angular velocity $2 π rad/s$ . Find the time after which both the particles $A$ and $B$ will collide.

Discussion

32.	A horizontal force is applied on spherical shell of radius R placed on rough surface. For what height h of force applied on shell will the shell always perform pure rolling motion irrespective of magnitude of force applied?
Answer» A horizontal force is applied on spherical shell of radius $R$ placed on rough surface. For what height h of force applied on shell will the shell always perform pure rolling motion irrespective of magnitude of force applied?

Discussion

33.	The ratio of powers dissipated respectively in R and 3R, as shown is
Answer» The ratio of powers dissipated respectively in $R$ and $3 R$ , as shown is

Discussion

34.	Two large parallel planes charged uniformly with surface charge density σ and −σ are located as shown in the figure. Which one of the following graphs shows the variation of electric field along a line perpendicular to the planes as one moves from A to B ?
Answer» Two large parallel planes charged uniformly with surface charge density $σ$ and $- σ$ are located as shown in the figure. Which one of the following graphs shows the variation of electric field along a line perpendicular to the planes as one moves from A to B ?

Discussion

35.	At what temperature would the root mean square speed of a gas molecule have twice its value at 100∘C?
Answer» At what temperature would the root mean square speed of a gas molecule have twice its value at $100^{\circ}$ C?

Discussion

36.	A uniform vertical cylinder of cross-sectional area a floats, 90% submerged in an unknown liquid inside a tank with cross-sectional area four times that of cylinder. When cylinder is pushed down gently by x, the liquid comes up by x’ w.r.t. the original level. Then the ratio of x to x’ will be ___
Answer» A uniform vertical cylinder of cross-sectional area a floats, $90 %$ submerged in an unknown liquid inside a tank with cross-sectional area four times that of cylinder. When cylinder is pushed down gently by x, the liquid comes up by x’ w.r.t. the original level. Then the ratio of x to x’ will be ___

Discussion

37.	A cylindrical rod of mass M,L and radius R has two cords wound around it whose ends are attached to the ceiling. The rod is held horizontally with the two cords vertical. When the rod is released, cords unwind the rod rotates. Find the tension in the cords as they unwind
Answer» A cylindrical rod of mass M,L and radius R has two cords wound around it whose ends are attached to the ceiling. The rod is held horizontally with the two cords vertical. When the rod is released, cords unwind the rod rotates. Find the tension in the cords as they unwind

Discussion

38.	Radiation, with wavelength 6561 ˚A falls on a metal surface to produce photoelectrons. The electrons are made to enter a uniform magnetic field of 3×10−4 T. If the radius of the largest circular path followed by the electrons is 10 mm, the work function of the metal is close to:
Answer» Radiation, with wavelength $6561 ˚ A$ falls on a metal surface to produce photoelectrons. The electrons are made to enter a uniform magnetic field of $3 \times 10^{- 4} T$ . If the radius of the largest circular path followed by the electrons is $10 mm$ , the work function of the metal is close to:

Discussion

39.	An electron beam has an aperture 1mm2. A total of 6.0×1016 electrons go through any perpendicular cross-section per second. Find the current density in the beam.
Answer» An electron beam has an aperture $1 m m^{2}$ . A total of $6.0 \times 10^{16}$ electrons go through any perpendicular cross-section per second. Find the current density in the beam.

Discussion

40.	A particle is moving with uniform speed along the circumference of a circle of radius R under the action of a central fictitious force F which is inversely proportional to R3. Its time period of revolution will be given by:
Answer» A particle is moving with uniform speed along the circumference of a circle of radius $R$ under the action of a central fictitious force $F$ which is inversely proportional to $R^{3} .$ Its time period of revolution will be given by:

Discussion

41.	The engine of car produces an acceleration 4 m/s² in the car if the car pulls and other car of the same mass what will be the acceleration produced _______ .
Answer» The engine of car produces an acceleration 4 m/s² in the car if the car pulls and other car of the same mass what will be the acceleration produced _______ .

Discussion

42.	A train starting from rest attains a maximum speed of 54 km/h in 30 sec with uniform acceleration, it then travels with this speed for 40 sec. and is then bought to rest in further 30 sec with uniform retardation , calculate the total distance travelled.
Answer» A train starting from rest attains a maximum speed of 54 km/h in 30 sec with uniform acceleration, it then travels with this speed for 40 sec. and is then bought to rest in further 30 sec with uniform retardation , calculate the total distance travelled.

Discussion

43.	Angle of incidence is equal to angle of emergences in which condition .it is not equal always
Answer» Angle of incidence is equal to angle of emergences in which condition .it is not equal always

Discussion

44.	1. 32 gram of oxygen gas at temperature 27'C is compressed adiabatically to 1/3 of its initial volume. Calculatethe change in internal energy. (y 1.5 for oxygen
Answer» 1. 32 gram of oxygen gas at temperature 27'C is compressed adiabatically to 1/3 of its initial volume. Calculatethe change in internal energy. (y 1.5 for oxygen

Discussion

45.	A message signal m(t) and the correspondiing DSB-SC signal s(t) are given below:m(t)=sinc(1000t) sinc2(2000t)s(t)=m(t)cos(2πfct)The carrier signal fc=2 MHz. If sinc(t)=sin(πt)πt, then the bondwidth of the DSBSC, signal will be _____ kHz.5
Answer» A message signal $m (t)$ and the correspondiing DSB-SC signal $s (t)$ are given below: $m (t) = sin c (1000 t) sin c^{2} (2000 t)$ $s (t) = m (t) cos (2 π f_{c} t)$ The carrier signal $f_{c} = 2 M H z$ . If $sin c (t) = \frac{sin (π t)}{π t}$ , then the bondwidth of the DSBSC, signal will be _____ kHz. 5

Discussion

46.	A coil of inductance L=2.0μH and resistance R=1.0Ω is connected to a source of constant emf ϵ=3.0V. Resistance R0=2.0Ω is connected in parallel with the coil.The amount of heat generated in the coil after the switch Sw is disconected is (in microjoule)? (The internal resistance of the source is negligible.)
Answer» A coil of inductance $L = 2.0 μ H$ and resistance $R = 1.0 Ω$ is connected to a source of constant emf $ϵ = 3.0 V$ . Resistance $R_{0} = 2.0 Ω$ is connected in parallel with the coil.The amount of heat generated in the coil after the switch $S_{w}$ is disconected is (in microjoule)? (The internal resistance of the source is negligible.)

Discussion

47.	A stone tied to a string of length L is whirled in a vertical circle with the other end of the string at the centre. At a certain instant of time, the stone is at its lowest position, and has a speed u. The magnitude of the change in its velocity as it reaches a position where the string is horizontal is
Answer» A stone tied to a string of length L is whirled in a vertical circle with the other end of the string at the centre. At a certain instant of time, the stone is at its lowest position, and has a speed u. The magnitude of the change in its velocity as it reaches a position where the string is horizontal is

Discussion

48.	There are n electrons of charge e on a spherical drop of oil of density ρ. It is in equilibrium in air in the electric filed E. Then radius of drop is
Answer» There are $n$ electrons of charge $e$ on a spherical drop of oil of density $ρ$ . It is in equilibrium in air in the electric filed $E$ . Then radius of drop is

Discussion

49.	a sand is poured on a conveyor belt at the rate of 2kg\s if belt is moving horizontally with velocity 4m\s then additional force required by the engine to keep the belt moving with same constant velocity
Answer» a sand is poured on a conveyor belt at the rate of 2kg\s if belt is moving horizontally with velocity 4m\s then additional force required by the engine to keep the belt moving with same constant velocity

Discussion

50.	An open organ pipe has fundamental frequency of 300 Hz. The first overtone of this organ pipe is same as the first overtone of a closed organ pipe. Find the length of the closed organ pipe?[speed of sound in air =330 m/s]
Answer» An open organ pipe has fundamental frequency of $300 Hz$ . The first overtone of this organ pipe is same as the first overtone of a closed organ pipe. Find the length of the closed organ pipe? [speed of sound in air $= 330 m/s$ ]

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

In the given circuit, charge Q2 on the 2 μF capacitor changes as C is varied from 1 μF to 3 μF. Q2 as a function of C is given properly by(figures are drawn schematically and not to scale)

The introduction of a metal plate between the plates of a parallel plate capacitor increases its capacitance by 4.5 times. If d is the separation of the two plates of the capacitor, the thickness of the metal plate introduced is

A circular disc rolls down an inclined plane without slipping. What fraction of its total energy is translational energy?

Two bulbs are marked as ‘A’ having rating 60W, 220V &amp; ‘B’ having rating 100W, 220V. They are connected in parallel to a 220 V source. Which of the two will glow brighter?

what happens when high pressure is applied on ice? 1) it melts 2) it attains equilibrium 3) it remaims same 4) nome of these

A thermally insulated rigid container contains an ideal gas at 27oC. It is fitted with a heating coil of resistance 50Ω. A current is passed through the coil for 10 minutes by connecting it to a d.c. source of 10 V. The change in the internal energy is

A simple harmonic oscillator has a period of 0.01 sec and an amplitude of 0.2 m. The magnitude of the velocity in m sec−1 at the centre of oscillation is [JIPMER 1997]

The position of the particle is given by x=t2−4t+6 in m. The average speed of the particle in 5 sec is

A ball of mass 300 gram falls on an elevator moving up with a uniform velocity of 10 m/s. It hits the floor of elevator with speed of 15 m/s and suffers elastic collision. What will be rebounding speed of the ball from elevator floor?

Why does the position of other bands except bright fringe in the centre, depends on the wavelength in the diffraction??

Consider a car moving along a straight horizontal road with a speed of 72 km/h. If the coefficient of kinetic friction between the tyres and the road is 0.5, the shortest distance in which the car can be stopped is [g=10 m/s−2]

A point charge q exerts an electric force on a second point charge q2. If third charge q3 is brought near, the electric force of q1 exerted on q2 will? a)increase b)decrease c)remains unchanged d) increases if q3 is of same origin and decreases if q3 is of opposite orig

A block of mass 10 kg is slowly moved up on a smooth inclined plane of inclination θ by a person. Work done by the person to move the block through a distance of 2 m is 120 J. If force is applied in horizontal direction. Find out inclination angle θ. (Take g=10 m/s2)

A body is projected with speed 55m/s vertically upwards. The distance travelled by the body in time interval 4s to 8s?

A boat moves relative to water with a velocity which is 2.0 times than the river flow velocity. At what angle to the stream direction must the boat move to minimise drifting?

16. A solid cylinder rolls down an inclined plane of height 3 m and reaches the bottom of plane with angular velocity of2\sqrt2 rad/s The radius of cylinder must be \lbrack Take g = 10ms2\rbrack

A stone falls freely under gravity, covers distance h1,h2 and h3 in the first 5 sec, the next 5 sec and the further next 5 sec respectively. The relation between h1,h2 and h3 is:

Two transparent media of refractive indices μ1 and μ3 have a solid lens shaped transparent media of refractive index μ2 between them as shown in figure.The correct relation between refractive indices is:

The ratio of time constants during current growth and current decay of the circuit shown in figure is k:2, then k=___

In new system , the force between the masses given by F directly proportional to r^2 , then time period of revolution T is proportional to

The charge on a conductor is positive Q and its potential is V(i.e. the electric potential on its surface)If some more positive charge is added to it, what are the possible values of its new potential?

A wide vessel with a small hole at the bottom is filled with water and kerosene. Find the approximate velocity of the water flow if thickness of water layer is 30 cm and that of kerosene layer is 20 cm.Specific gravity of kerosene =0.8.

The figure shows a spherical capacitor with inner sphere earthed. If a=2 cm and b=3 cm, then the capacitance of the system is(Take k=9×109 Nm2/C2)

Thethreshold frequency for a certain metal is 3.3 × 1014Hz. If light of frequency 8.2 ×1014Hz is incident on the metal, predict the cutoff voltage for thephotoelectric emission.

A fully charged capacitor C with initial charge q0 is connected to a coil of inductance L at time t = 0. The time after which the energy is stored equally between electric and magnetic fields is

A horizontal force is applied on spherical shell of radius R placed on rough surface. For what height h of force applied on shell will the shell always perform pure rolling motion irrespective of magnitude of force applied?

The ratio of powers dissipated respectively in R and 3R, as shown is

Two large parallel planes charged uniformly with surface charge density σ and −σ are located as shown in the figure. Which one of the following graphs shows the variation of electric field along a line perpendicular to the planes as one moves from A to B ?

At what temperature would the root mean square speed of a gas molecule have twice its value at 100∘C?

A cylindrical rod of mass M,L and radius R has two cords wound around it whose ends are attached to the ceiling. The rod is held horizontally with the two cords vertical. When the rod is released, cords unwind the rod rotates. Find the tension in the cords as they unwind

Radiation, with wavelength 6561 ˚A falls on a metal surface to produce photoelectrons. The electrons are made to enter a uniform magnetic field of 3×10−4 T. If the radius of the largest circular path followed by the electrons is 10 mm, the work function of the metal is close to:

An electron beam has an aperture 1mm2. A total of 6.0×1016 electrons go through any perpendicular cross-section per second. Find the current density in the beam.

A particle is moving with uniform speed along the circumference of a circle of radius R under the action of a central fictitious force F which is inversely proportional to R3. Its time period of revolution will be given by:

The engine of car produces an acceleration 4 m/s² in the car if the car pulls and other car of the same mass what will be the acceleration produced _______ .

A train starting from rest attains a maximum speed of 54 km/h in 30 sec with uniform acceleration, it then travels with this speed for 40 sec. and is then bought to rest in further 30 sec with uniform retardation , calculate the total distance travelled.

Angle of incidence is equal to angle of emergences in which condition .it is not equal always

1. 32 gram of oxygen gas at temperature 27'C is compressed adiabatically to 1/3 of its initial volume. Calculatethe change in internal energy. (y 1.5 for oxygen

A message signal m(t) and the correspondiing DSB-SC signal s(t) are given below:m(t)=sinc(1000t) sinc2(2000t)s(t)=m(t)cos(2πfct)The carrier signal fc=2 MHz. If sinc(t)=sin(πt)πt, then the bondwidth of the DSBSC, signal will be _____ kHz.5

There are n electrons of charge e on a spherical drop of oil of density ρ. It is in equilibrium in air in the electric filed E. Then radius of drop is

a sand is poured on a conveyor belt at the rate of 2kg\s if belt is moving horizontally with velocity 4m\s then additional force required by the engine to keep the belt moving with same constant velocity

An open organ pipe has fundamental frequency of 300 Hz. The first overtone of this organ pipe is same as the first overtone of a closed organ pipe. Find the length of the closed organ pipe?[speed of sound in air =330 m/s]

Two bulbs are marked as ‘A’ having rating 60W, 220V & ‘B’ having rating 100W, 220V. They are connected in parallel to a 220 V source. Which of the two will glow brighter?