16569 + Interview Questions in Physics Page 4 InterviewSolution

151.	In an equilateral prism, if a ray is incident on the normal, the angle of the internally reflected ray deviates through .
Answer» In an equilateral prism, if a ray is incident on the normal, the angle of the internally reflected ray deviates through .

Discussion

152.	A movable pulley is used as : (a) a force multiplier (b) a speed multiplier (c) a device to change the direction of effort (d) an energy multiplier
Answer» A movable pulley is used as : (a) a force multiplier (b) a speed multiplier (c) a device to change the direction of effort (d) an energy multiplier

152.

A movable pulley is used as : (a) a force multiplier (b) a speed multiplier (c) a device to change the direction of effort (d) an energy multiplier

Answer»

A movable pulley is used as :

(a) a force multiplier

(b) a speed multiplier

(c) a device to change the direction of effort

(d) an energy multiplier

Discussion

153.	Question 4The figure shows a ray of light as it travels from medium A to medium B. Refractive index of the medium B relative to medium A is(a) √3√2(b) √2√3(c) 1√2(d) √2
Answer» Question 4 The figure shows a ray of light as it travels from medium A to medium B. Refractive index of the medium B relative to medium A is (a) $\frac{\sqrt{3}}{\sqrt{2}}$ (b) $\frac{\sqrt{2}}{\sqrt{3}}$ (c) $\frac{1}{\sqrt{2}}$ (d) $\sqrt{2}$

Discussion

154.	The other name of potential difference is: (a) ampereage (b) wattage (c) voltage (d) potential energy
Answer» The other name of potential difference is: (a) ampereage (b) wattage (c) voltage (d) potential energy

Discussion

155.

Answer the following:(1) P and Q are the two wires of same length and different cross sectional areas and made of same metal. Name the property which is same for both the wires and that which is different for both the wires.(2) Resistivity of some material is given below. State which one will be the best conductor. Material Copper Aluminium Silver Nickel Resistivity (Ωm) 1.62 × 10−8 2.63 × 10−8 1.60 × 10−8 6.84 × 10−8 (3) If the resistance of wire A is four times the resistance of wire B, find the ratio of their cross sectional areas.(4) Two dissimilar bulbs are connected in series, which bulb will be brighter?

Answer»

Answer the following:

(1) P and Q are the two wires of same length and different cross sectional areas and made of same metal. Name the property which is same for both the wires and that which is different for both the wires.

(2) Resistivity of some material is given below. State which one will be the best conductor.

Material		Copper		Aluminium		Silver		Nickel
Resistivity (Ωm)		1.62 × 10⁻⁸		2.63 × 10⁻⁸		1.60 × 10⁻⁸		6.84 × 10⁻⁸

(3) If the resistance of wire A is four times the resistance of wire B, find the ratio of their cross sectional areas.

(4) Two dissimilar bulbs are connected in series, which bulb will be brighter?

Discussion

156.	If a charge q is moving on a circular path of radius R with speed v then find the equivalent current in the loop due to this charge
Answer» If a charge q is moving on a circular path of radius R with speed v then find the equivalent current in the loop due to this charge

Discussion

157.	The magnetic field in a certain region is given by →B=(4^i−^k) T. How much magnetic flux passes through the loop of area 0.1 m2 in this region, if the loop lies flat in xy plane?
Answer» The magnetic field in a certain region is given by $\to B = (4^i -^k) T$ . How much magnetic flux passes through the loop of area $0.1 m^{2}$ in this region, if the loop lies flat in $x y$ plane?

Discussion

158.	The given figure shows a circuit diagram containing 12 cells, each of EMF 1.5 V and internal resistance 0.25Ω. Calculate the: (a) total internal resistance. (b) total EMF. (c) reading shown by the ammeter. (d) Current in 12Ω and 8Ω resistors. [5 MARKS]
Answer» The given figure shows a circuit diagram containing 12 cells, each of EMF 1.5 V and internal resistance $0.25 Ω$ . Calculate the: (a) total internal resistance. (b) total EMF. (c) reading shown by the ammeter. (d) Current in $12 Ω$ and $8 Ω$ resistors. [5 MARKS]

Discussion

159.	There are two boxes A & B. Cell phones are kept in both the boxes, all air is sucked from box A and then closed by a device. While box B is simply closed by a device without sucking air from it. A call is made simultaneously on both the phones, but sound comes only from box B. This is because Statement 1: In box B there are air particles to vibrate but in box A there is vacuum Statement 2: Sound needs a medium for propagation
Answer» There are two boxes A & B. Cell phones are kept in both the boxes, all air is sucked from box A and then closed by a device. While box B is simply closed by a device without sucking air from it. A call is made simultaneously on both the phones, but sound comes only from box B. This is because Statement 1: In box B there are air particles to vibrate but in box A there is vacuum Statement 2: Sound needs a medium for propagation

159.

There are two boxes A & B. Cell phones are kept in both the boxes, all air is sucked from box A and then closed by a device. While box B is simply closed by a device without sucking air from it. A call is made simultaneously on both the phones, but sound comes only from box B. This is because Statement 1: In box B there are air particles to vibrate but in box A there is vacuum Statement 2: Sound needs a medium for propagation

Answer»

There are two boxes A & B. Cell phones are kept in both the boxes, all air is sucked from box A and then closed by a device. While box B is simply closed by a device without sucking air from it. A call is made simultaneously on both the phones, but sound comes only from box B. This is because
Statement 1: In box B there are air particles to vibrate but in box A there is vacuum

Statement 2: Sound needs a medium for propagation

Discussion

160.	In the motion of a projectile freely under gravity, its
Answer» In the motion of a projectile freely under gravity, its

Discussion

161.	under free fall the ball is acting in direction of gravity which is always downward so why we should take 'g' as negative?
Answer» under free fall the ball is acting in direction of gravity which is always downward so why we should take 'g' as negative?

Discussion

162.	16.Refractive index of a medium with respect to air is \sqrt2,find the critical angle between the two medium
Answer» 16.Refractive index of a medium with respect to air is \sqrt2,find the critical angle between the two medium

Discussion

163.	25. The power developed in an unknown resistance Ris same as the power developed in the resistance of 8Ω, when these are connected separately across a battery of internal resistance 4Ω . The value of R is (1) 2Ω (2) 4Ω (3) 6Ω (4) 16Ω
Answer» 25. The power developed in an unknown resistance Ris same as the power developed in the resistance of 8Ω, when these are connected separately across a battery of internal resistance 4Ω . The value of R is (1) 2Ω (2) 4Ω (3) 6Ω (4) 16Ω

Discussion

164.	The concave mirror is a ___ whose reflecting surface is towards the center of the sphere of which the mirror is a part.
Answer» The concave mirror is a ___ whose reflecting surface is towards the center of the sphere of which the mirror is a part.

Discussion

165.	State the principle of an electric generator.
Answer» State the principle of an electric generator.

Discussion

166.	5.Can a centripetal force ever do work on an object ? Explain
Answer» 5.Can a centripetal force ever do work on an object ? Explain

Discussion

167.	Consider the CMOS implementationThe logic circuit equivalent to the above CMOS implementation is
Answer» Consider the CMOS implementation The logic circuit equivalent to the above CMOS implementation is

Discussion

168.	A light ray is incident normally on a plane mirror. (a) What is its angle of incidence ? (b) What is the direction of reflected ray ? Show it on a diagram.
Answer» A light ray is incident normally on a plane mirror. (a) What is its angle of incidence ? (b) What is the direction of reflected ray ? Show it on a diagram.

168.

A light ray is incident normally on a plane mirror. (a) What is its angle of incidence ? (b) What is the direction of reflected ray ? Show it on a diagram.

Answer»

A light ray is incident normally on a plane mirror.

(a) What is its angle of incidence ?

(b) What is the direction of reflected ray ? Show it on a diagram.

Discussion

169.	A current through a horizontal power line flows in east to west direction. The direction of magnetic field at a point directly below it is
Answer» A current through a horizontal power line flows in east to west direction. The direction of magnetic field at a point directly below it is

Discussion

170.	A wire is stratched 40%. The %change in in its resis†an ce i
Answer» A wire is stratched 40%. The %change in in its resis†an ce i

Discussion

171.	Two separate monochromatic light beams A and B of the same intensity (energy per unit area per unit time) are falling normally on a unit area of a metallic surface. Their wavelength is λA and λB respectively. Assuming that all the incident light is used in ejecting the photoelectrons, the ratio of the number of photoelectrons ejected by beam A to that beam B is-
Answer» Two separate monochromatic light beams $A$ and $B$ of the same intensity (energy per unit area per unit time) are falling normally on a unit area of a metallic surface. Their wavelength is $λ_{A}$ and $λ_{B}$ respectively. Assuming that all the incident light is used in ejecting the photoelectrons, the ratio of the number of photoelectrons ejected by beam $A$ to that beam $B$ is-

Discussion

172.	resistance of a metal wire of length 1 meter is 26 ohm at 20 degree celcius . if the diameter of the wire is 3mm, what will be the resistivity of the metal at that temperature ?
Answer» resistance of a metal wire of length 1 meter is 26 ohm at 20 degree celcius . if the diameter of the wire is 3mm, what will be the resistivity of the metal at that temperature ?

Discussion

173.	metre stick us pivoted about its centre , wax of mass 20 g travel hurizontally and perpendicular to it at 5 m/s striks and adhers to one end and stic rotate in horizontal circle . I of stick and wax about pivot us .02 kgm\ast2. initial angular velocity=?
Answer» metre stick us pivoted about its centre , wax of mass 20 g travel hurizontally and perpendicular to it at 5 m/s striks and adhers to one end and stic rotate in horizontal circle . I of stick and wax about pivot us .02 kgm\ast2. initial angular velocity=?

Discussion

174.	Can the scientists use magnified UV rays of sun which can produce lot heat energy that can used in nuclear fusion
Answer» Can the scientists use magnified UV rays of sun which can produce lot heat energy that can used in nuclear fusion

Discussion

175.	The probability of survival of a radio active nucleus for one mean life is
Answer» The probability of survival of a radio active nucleus for one mean life is

Discussion

176.	If number density does not depend on temperature then why it is not taken as a constant in the resistivity equation where resistivity is inversely proportional to number density.
Answer» If number density does not depend on temperature then why it is not taken as a constant in the resistivity equation where resistivity is inversely proportional to number density.

Discussion

177.	if the electric field intensity in a fair weather atmosphre is 100V/m thencthe total charge oncthe earrh surface i
Answer» if the electric field intensity in a fair weather atmosphre is 100V/m thencthe total charge oncthe earrh surface i

Discussion

178.	During the phase change, the temperature of a substance_____.
Answer» During the phase change, the temperature of a substance_____.

178.

During the phase change, the temperature of a substance_____.

Answer»

During the phase change, the temperature of a substance_____.

Discussion

179.	Solve:(1) An object of size 7 cm is placed at 25 cm in front of concave mirror of focal length 15 cm. At what distance from the mirror should a screen be placed, so that we can get a sharp and clear image. Find nature and size of the image.(2) An object of height 5 cm is held 20 cm away from converging lens of focal length 10 cm. Find the position, nature and size of the image formed.(3) An object is placed at a distance of 10 cm from a convex lens of focal length 12 cm. Find the position and nature of the image.
Answer» Solve: (1) An object of size 7 cm is placed at 25 cm in front of concave mirror of focal length 15 cm. At what distance from the mirror should a screen be placed, so that we can get a sharp and clear image. Find nature and size of the image. (2) An object of height 5 cm is held 20 cm away from converging lens of focal length 10 cm. Find the position, nature and size of the image formed. (3) An object is placed at a distance of 10 cm from a convex lens of focal length 12 cm. Find the position and nature of the image.

179.

Solve:(1) An object of size 7 cm is placed at 25 cm in front of concave mirror of focal length 15 cm. At what distance from the mirror should a screen be placed, so that we can get a sharp and clear image. Find nature and size of the image.(2) An object of height 5 cm is held 20 cm away from converging lens of focal length 10 cm. Find the position, nature and size of the image formed.(3) An object is placed at a distance of 10 cm from a convex lens of focal length 12 cm. Find the position and nature of the image.

Answer»

Solve:

(1) An object of size 7 cm is placed at 25 cm in front of concave mirror of focal length 15 cm. At what distance from the mirror should a screen be placed, so that we can get a sharp and clear image. Find nature and size of the image.

(2) An object of height 5 cm is held 20 cm away from converging lens of focal length 10 cm. Find the position, nature and size of the image formed.

(3) An object is placed at a distance of 10 cm from a convex lens of focal length 12 cm. Find the position and nature of the image.

Discussion

180.	When the light ray is ___________ to the boundary between two medium, light does not bend.
Answer» When the light ray is ___________ to the boundary between two medium, light does not bend.

Discussion

181.	If a half wave rectifier circuit is operating from 50 Hz mains the fundamental frequency in ripple will be
Answer» If a half wave rectifier circuit is operating from 50 Hz mains the fundamental frequency in ripple will be

Discussion

182.	17. 2 solenoid A & B spaced closed to each other and sharing same cylindrical axis have 400 & 700 turns respectively .A current of 3.5 ampere in coil A produces an average flux of 300 micro Webber through each turns of A and flux of 90 micro webber through each turns of B .calculate 1) mutual inductance of 2 solenoids 2)self inductance of A 3) what EMF induced in B when current In A increase at rate of o.5 Ampere/second
Answer» 17. 2 solenoid A & B spaced closed to each other and sharing same cylindrical axis have 400 & 700 turns respectively .A current of 3.5 ampere in coil A produces an average flux of 300 micro Webber through each turns of A and flux of 90 micro webber through each turns of B .calculate 1) mutual inductance of 2 solenoids 2)self inductance of A 3) what EMF induced in B when current In A increase at rate of o.5 Ampere/second

Discussion

183.	The Chipko Andolan is associated with: (a) Tigers (b) Turtles (c) Trees (d) Tomatoes
Answer» The Chipko Andolan is associated with: (a) Tigers (b) Turtles (c) Trees (d) Tomatoes

Discussion

184.	79. Two point charge of +3 micro coulomb and +4 micro coulomb repel each other with a force of 10N. If each is given an additional charge of -6 micro coulomb, the the new force will be?
Answer» 79. Two point charge of +3 micro coulomb and +4 micro coulomb repel each other with a force of 10N. If each is given an additional charge of -6 micro coulomb, the the new force will be?

Discussion

185.	An organ pipe closed at one end has fundamental frequency of 1500Hz. The max. number of overtone generated by this pipe which a normal person can hear is
Answer» An organ pipe closed at one end has fundamental frequency of 1500Hz. The max. number of overtone generated by this pipe which a normal person can hear is

Discussion

186.	Four particles of equal mass are mobing round a circle of radius r due to their mutual gravitational attraction .find the angular velocity of each particle
Answer» Four particles of equal mass are mobing round a circle of radius r due to their mutual gravitational attraction .find the angular velocity of each particle

Discussion

187.	Why does mass of positively charged particles such as protons depend on the gas taken in discharge tube whereas mass of negatively charged particles such as electrons is independent of the gas?
Answer» Why does mass of positively charged particles such as protons depend on the gas taken in discharge tube whereas mass of negatively charged particles such as electrons is independent of the gas?

Discussion

188.	Molten-wax of mass m is dropped (from negligible height) on a block of mass M which is oscillatingon a frictionless table as shown. Select the incorrect option(1) If wax is dropped at extreme position, amplitude does not change(2) If wax is dropped at mean position, amplitude decreases(3) If wax is dropped at mean position, the time period decreases(4) If wax is dropped at extreme position, then time period inceases(291)
Answer» Molten-wax of mass m is dropped (from negligible height) on a block of mass M which is oscillatingon a frictionless table as shown. Select the incorrect option(1) If wax is dropped at extreme position, amplitude does not change(2) If wax is dropped at mean position, amplitude decreases(3) If wax is dropped at mean position, the time period decreases(4) If wax is dropped at extreme position, then time period inceases(291)

Discussion

189.	What is angle of deviation
Answer» What is angle of deviation

Discussion

190.	An alpha particle is moving along x axis in xy plane with v= 10 to the power 3 m\|sec.A magnetic field of 10 Tesla is presented along z axis .Find out the direction and magnitude of force on the particle.
Answer» An alpha particle is moving along x axis in xy plane with v= 10 to the power 3 m\|sec.A magnetic field of 10 Tesla is presented along z axis .Find out the direction and magnitude of force on the particle.

Discussion

191.	Calculate the critical angle for glass-air interface if a ray of light incident on a glass surface is deviated through 15 degree when angle of incidence is 45 degree
Answer» Calculate the critical angle for glass-air interface if a ray of light incident on a glass surface is deviated through 15 degree when angle of incidence is 45 degree

Discussion

192.	A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. What is the direction of magnetic field?
Answer» A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. What is the direction of magnetic field?

Discussion

193.	84.The intensity variation in the interference pattern obtained with the help of two coherent sources 5% of the average intensity , find the ratio of intensities of two sources?
Answer» 84.The intensity variation in the interference pattern obtained with the help of two coherent sources 5% of the average intensity , find the ratio of intensities of two sources?

Discussion

194.	Write the approximate wavelength for (i) blue , and (ii) red light.
Answer» Write the approximate wavelength for (i) blue , and (ii) red light.

Discussion

195.	Rutherford’s model of an atom could not explain the behavior of
Answer» Rutherford’s model of an atom could not explain the behavior of

Discussion

196.	A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 feet tall building. After a fall of 30 feet, their respective kinetic energies will be in the ratio of
Answer» A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 feet tall building. After a fall of 30 feet, their respective kinetic energies will be in the ratio of

Discussion

197.	An ideal solenoid of cross-sectional area 104m2 has500 turns per metre. At the centre of this solenoid,another coil of 100 turns is wrapped closely aroundit. If the current in the coil changes from 0 to 2 Ain3.14 ms, the emf developed in the second coil is(1) 1 mV(3) 3 mV(2) 2 mV(4) 4 mV
Answer» An ideal solenoid of cross-sectional area 104m2 has500 turns per metre. At the centre of this solenoid,another coil of 100 turns is wrapped closely aroundit. If the current in the coil changes from 0 to 2 Ain3.14 ms, the emf developed in the second coil is(1) 1 mV(3) 3 mV(2) 2 mV(4) 4 mV

Discussion

198.	Two liquids A and B are at 32∘C and 24∘C. When mixed in equal masses the temperature of the mixture is found to be 28∘C. The ratio of specific heats of liquid A to that of liquid B will be:
Answer» Two liquids $A$ and $B$ are at $32^{\circ} C$ and $24^{\circ} C$ . When mixed in equal masses the temperature of the mixture is found to be $28^{\circ} C$ . The ratio of specific heats of liquid $A$ to that of liquid $B$ will be:

Discussion

199.	What is tidal energy?
Answer» What is tidal energy?

Discussion

200.	A communications satellite in orbit sends a parallel beam of signals down to earth. If these signals obey the same laws of reflection as light and are to be focussed onto a small receiving aerial, what should be the best shape of the metal 'dish' used to collect them ?
Answer» A communications satellite in orbit sends a parallel beam of signals down to earth. If these signals obey the same laws of reflection as light and are to be focussed onto a small receiving aerial, what should be the best shape of the metal 'dish' used to collect them ?

Discussion

Explore topic-wise InterviewSolutions in .

In an equilateral prism, if a ray is incident on the normal, the angle of the internally reflected ray deviates through .

A movable pulley is used as : (a) a force multiplier (b) a speed multiplier (c) a device to change the direction of effort (d) an energy multiplier

Question 4The figure shows a ray of light as it travels from medium A to medium B. Refractive index of the medium B relative to medium A is(a) √3√2(b) √2√3(c) 1√2(d) √2

The other name of potential difference is: (a) ampereage (b) wattage (c) voltage (d) potential energy

If a charge q is moving on a circular path of radius R with speed v then find the equivalent current in the loop due to this charge

The magnetic field in a certain region is given by →B=(4^i−^k) T. How much magnetic flux passes through the loop of area 0.1 m2 in this region, if the loop lies flat in xy plane?

The given figure shows a circuit diagram containing 12 cells, each of EMF 1.5 V and internal resistance 0.25Ω. Calculate the: (a) total internal resistance. (b) total EMF. (c) reading shown by the ammeter. (d) Current in 12Ω and 8Ω resistors. [5 MARKS]

In the motion of a projectile freely under gravity, its

under free fall the ball is acting in direction of gravity which is always downward so why we should take 'g' as negative?

16.Refractive index of a medium with respect to air is \sqrt2,find the critical angle between the two medium

25. The power developed in an unknown resistance Ris same as the power developed in the resistance of 8Ω, when these are connected separately across a battery of internal resistance 4Ω . The value of R is (1) 2Ω (2) 4Ω (3) 6Ω (4) 16Ω

The concave mirror is a ___ whose reflecting surface is towards the center of the sphere of which the mirror is a part.

State the principle of an electric generator.

5.Can a centripetal force ever do work on an object ? Explain

Consider the CMOS implementationThe logic circuit equivalent to the above CMOS implementation is

A light ray is incident normally on a plane mirror. (a) What is its angle of incidence ? (b) What is the direction of reflected ray ? Show it on a diagram.

A current through a horizontal power line flows in east to west direction. The direction of magnetic field at a point directly below it is

A wire is stratched 40%. The %change in in its resis†an ce i

resistance of a metal wire of length 1 meter is 26 ohm at 20 degree celcius . if the diameter of the wire is 3mm, what will be the resistivity of the metal at that temperature ?

metre stick us pivoted about its centre , wax of mass 20 g travel hurizontally and perpendicular to it at 5 m/s striks and adhers to one end and stic rotate in horizontal circle . I of stick and wax about pivot us .02 kgm\ast2. initial angular velocity=?

Can the scientists use magnified UV rays of sun which can produce lot heat energy that can used in nuclear fusion

The probability of survival of a radio active nucleus for one mean life is

If number density does not depend on temperature then why it is not taken as a constant in the resistivity equation where resistivity is inversely proportional to number density.

if the electric field intensity in a fair weather atmosphre is 100V/m thencthe total charge oncthe earrh surface i

During the phase change, the temperature of a substance_____.

When the light ray is ___________ to the boundary between two medium, light does not bend.

If a half wave rectifier circuit is operating from 50 Hz mains the fundamental frequency in ripple will be

The Chipko Andolan is associated with: (a) Tigers (b) Turtles (c) Trees (d) Tomatoes

79. Two point charge of +3 micro coulomb and +4 micro coulomb repel each other with a force of 10N. If each is given an additional charge of -6 micro coulomb, the the new force will be?

An organ pipe closed at one end has fundamental frequency of 1500Hz. The max. number of overtone generated by this pipe which a normal person can hear is

Four particles of equal mass are mobing round a circle of radius r due to their mutual gravitational attraction .find the angular velocity of each particle

Why does mass of positively charged particles such as protons depend on the gas taken in discharge tube whereas mass of negatively charged particles such as electrons is independent of the gas?

What is angle of deviation

An alpha particle is moving along x axis in xy plane with v= 10 to the power 3 m|sec.A magnetic field of 10 Tesla is presented along z axis .Find out the direction and magnitude of force on the particle.

Calculate the critical angle for glass-air interface if a ray of light incident on a glass surface is deviated through 15 degree when angle of incidence is 45 degree

A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. What is the direction of magnetic field?

84.The intensity variation in the interference pattern obtained with the help of two coherent sources 5% of the average intensity , find the ratio of intensities of two sources?

Write the approximate wavelength for (i) blue , and (ii) red light.

Rutherford’s model of an atom could not explain the behavior of

A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 feet tall building. After a fall of 30 feet, their respective kinetic energies will be in the ratio of

An ideal solenoid of cross-sectional area 104m2 has500 turns per metre. At the centre of this solenoid,another coil of 100 turns is wrapped closely aroundit. If the current in the coil changes from 0 to 2 Ain3.14 ms, the emf developed in the second coil is(1) 1 mV(3) 3 mV(2) 2 mV(4) 4 mV

Two liquids A and B are at 32∘C and 24∘C. When mixed in equal masses the temperature of the mixture is found to be 28∘C. The ratio of specific heats of liquid A to that of liquid B will be:

What is tidal energy?

A communications satellite in orbit sends a parallel beam of signals down to earth. If these signals obey the same laws of reflection as light and are to be focussed onto a small receiving aerial, what should be the best shape of the metal 'dish' used to collect them ?