16569 + Interview Questions in Physics

1.	a charge q is placed inside a horizontal circle of radius r, and a hemisphere of this radius is erected about the charge.Compute the electric flux through the closed surface that consists of the hemisphere and the planar circle.Do not use Gauss Law.
Answer» a charge q is placed inside a horizontal circle of radius r, and a hemisphere of this radius is erected about the charge.Compute the electric flux through the closed surface that consists of the hemisphere and the planar circle.Do not use Gauss Law.

Discussion

2.	A beam with overhang supports two concentrated loads P and Q as shown in the figure. The ratio of Q/P, so that deflection at D will be zero is_____4
Answer» A beam with overhang supports two concentrated loads P and Q as shown in the figure. The ratio of Q/P, so that deflection at D will be zero is_____ 4

Discussion

3.	A point source of light is kept at adistance of 15cm from a converging lens on its optical axis.A sharp image is formed on the screen which is placed at a distance 20cm from lens find the focal length of lens
Answer» A point source of light is kept at adistance of 15cm from a converging lens on its optical axis.A sharp image is formed on the screen which is placed at a distance 20cm from lens find the focal length of lens

Discussion

4.	Which property of sound helps the brain to interpret the frequency of a sound wave?
Answer» Which property of sound helps the brain to interpret the frequency of a sound wave?

Discussion

5.	The moment of inertia of a body moving with angular velocity w decreases from I to I/3 without any external torque. Calculate the new average velocity of bo
Answer» The moment of inertia of a body moving with angular velocity w decreases from I to I/3 without any external torque. Calculate the new average velocity of bo

Discussion

6.	A point charge produces an electric field of magnitude 5.0Nc^-1 at a distance 40cm it . What is the magnitude of charge
Answer» A point charge produces an electric field of magnitude 5.0Nc^-1 at a distance 40cm it . What is the magnitude of charge

Discussion

7.	15.find the magnetic field at the centre of the loop O shown in the figure
Answer» 15.find the magnetic field at the centre of the loop O shown in the figure

Discussion

8.	A ray light incident on a lens parallel to its principal axis, after refraction passes through or appears to come from : (a) its first focus (b) its optical centre (c) its second focus (d) the centre of curvation of its second surface.
Answer» A ray light incident on a lens parallel to its principal axis, after refraction passes through or appears to come from : (a) its first focus (b) its optical centre (c) its second focus (d) the centre of curvation of its second surface.

8.

A ray light incident on a lens parallel to its principal axis, after refraction passes through or appears to come from : (a) its first focus (b) its optical centre (c) its second focus (d) the centre of curvation of its second surface.

Answer»

A ray light incident on a lens parallel to its principal axis, after refraction passes through or appears to come from :

(a) its first focus

(b) its optical centre

(c) its second focus

(d) the centre of curvation of its second surface.

Discussion

9.	The relation between current in a conductor and time is shown in the figure.(iii) If the resistance of the conductor is R then the total heat dissipated across resistance R is[1 Mark]
Answer» The relation between current in a conductor and time is shown in the figure. $(i i i)$ If the resistance of the conductor is $R$ then the total heat dissipated across resistance $R$ is $[$ 1 Mark $]$

Discussion

10.	Question 19Which part of the eye gets affected if someone is suffering from cataract? How is it treated?
Answer» Question 19 Which part of the eye gets affected if someone is suffering from cataract? How is it treated?

10.

Question 19Which part of the eye gets affected if someone is suffering from cataract? How is it treated?

Answer»

Question 19

Which part of the eye gets affected if someone is suffering from cataract? How is it treated?

Discussion

11.	Center of Mass
Answer» Center of Mass

Discussion

12.	A wire of resistance 10Ω is stretched such that its area becomes 13rd and its volume remains constant. What will be the new resistance?
Answer» A wire of resistance $10 Ω$ is stretched such that its area becomes $\frac{1}{3}$ rd and its volume remains constant. What will be the new resistance?

Discussion

13.	Mention names of two phenomenon due to which rainbow is formed.
Answer» Mention names of two phenomenon due to which rainbow is formed.

Discussion

14.	An object is midway between the lens and the mirror as shown. The mirror's radius of curvature is 20.0 cm and the lens has a focal length of −503 cm. Considering only the rays that leaves the object travelling first towards the mirror, find the overall magnification.
Answer» An object is midway between the lens and the mirror as shown. The mirror's radius of curvature is $20.0 cm$ and the lens has a focal length of $- \frac{50}{3} cm$ . Considering only the rays that leaves the object travelling first towards the mirror, find the overall magnification.

Discussion

15.	What is the nature of the image formed in: Concave lens Convex lensAlso give one use of each lens.
Answer» What is the nature of the image formed in: Concave lens Convex lens Also give one use of each lens.

Discussion

16.	Which graph represents the relation between resistance and area of a conductor when other parameters are constant?
Answer» Which graph represents the relation between resistance and area of a conductor when other parameters are constant?

Discussion

17.	Around a current carrying wire, there is a ___.
Answer» Around a current carrying wire, there is a ___.

Discussion

18.	A student has obtained the image of a distant object with a concave mirror to determine its focal length. If he has selected a well - illuminated red building as object, which of the following correctly describes the features of the image formed?
Answer» A student has obtained the image of a distant object with a concave mirror to determine its focal length. If he has selected a well - illuminated red building as object, which of the following correctly describes the features of the image formed?

Discussion

19.	an inductor l=0.03 henry and a resistor r=150 ohm are connect in series to a battery of 15 v emf ina circuit shown below the key k1 has been kept closed for a long time then at t=0 k1 is opened and key k2 is closed simultaneously At t=1ms the current in the circuit will be
Answer» an inductor l=0.03 henry and a resistor r=150 ohm are connect in series to a battery of 15 v emf ina circuit shown below the key k1 has been kept closed for a long time then at t=0 k1 is opened and key k2 is closed simultaneously At t=1ms the current in the circuit will be

Discussion

20.	A child drops a toy from the top of a building, it takes 1 s to reach the ground. Find the height of the building and the average speed of the toy respectively.(Take g = 10 ms−2)
Answer» A child drops a toy from the top of a building, it takes 1 s to reach the ground. Find the height of the building and the average speed of the toy respectively. (Take g = $10 m s^{- 2}$ )

Discussion

21.

A charged particle moves through a region of magnetic field pointing in the direction perpendicular to its direction of velocity. Then during its subsequent motion, (1) Its momentum changes but the kinetic energy remains constant. (2) Its momentum and kinetic energy both changes. (3) Its momentum and kinetic energy both remains constant. (4) Its kinetic energy changes but the momentum remains constant.

Answer»

A charged particle moves through a region of magnetic field pointing in the direction perpendicular to its direction of velocity. Then during its subsequent motion,

(1)	Its momentum changes but the kinetic energy remains constant.
(2)	Its momentum and kinetic energy both changes.
(3)	Its momentum and kinetic energy both remains constant.
(4)	Its kinetic energy changes but the momentum remains constant.

Discussion

22.	Tidal energy is harnessed by constructing
Answer» Tidal energy is harnessed by constructing

Discussion

23.	why focal length of convex mirror and convex lens is '+' ( positive ) explain with the help of diagram if needed .
Answer» why focal length of convex mirror and convex lens is '+' ( positive ) explain with the help of diagram if needed .

Discussion

24.	The radius of a coil of wire with N turns is 0.22 m and 3.5 A current flows clockwise as shown in figure. A long straight wire is carrying a current 54 A towards the left as shown. The shortest distance between the straight wire and the coil is 0.05 m. The magnetic field at the centre of coil is zero. The number of turns N in the coil is:
Answer» The radius of a coil of wire with $N$ turns is $0.22 m$ and $3.5 A$ current flows clockwise as shown in figure. A long straight wire is carrying a current $54 A$ towards the left as shown. The shortest distance between the straight wire and the coil is $0.05 m$ . The magnetic field at the centre of coil is zero. The number of turns $N$ in the coil is:

Discussion

25.	what equal charge would have to be placed on earth and moon to neutralize their gravitational attraction given mass of earth=10 ki power25kg and mass of moon =10 ki power 23kg
Answer» what equal charge would have to be placed on earth and moon to neutralize their gravitational attraction given mass of earth=10 ki power25kg and mass of moon =10 ki power 23kg

Discussion

26.	35. Figure shows the variation of electric field intensity E versus distance x. What is the potential difference betweenthe points at x = 2 m and at x = 6 m from O?
Answer» 35. Figure shows the variation of electric field intensity E versus distance x. What is the potential difference betweenthe points at x = 2 m and at x = 6 m from O?

Discussion

27.	Two wires of the same material and same length have radii r1 and r2 respectively.Compare 1. Their resistance 2. Their specific resistance
Answer» Two wires of the same material and same length have radii r1 and r2 respectively.Compare 1. Their resistance 2. Their specific resistance

27.

Two wires of the same material and same length have radii r1 and r2 respectively.Compare 1. Their resistance 2. Their specific resistance

Answer»

Two wires of the same material and same length have radii r1 and r2 respectively.Compare

1. Their resistance

2. Their specific resistance

Discussion

28.	The correct relation between α (ratio of collector current to emitter current) and β (ratio of collector current to base current) of a transistor is :
Answer» The correct relation between $α$ $($ ratio of collector current to emitter current $)$ and $β$ $($ ratio of collector current to base current $)$ of a transistor is :

Discussion

29.	In the figure given, PR = 22 cm, SN = MQ = 3 cm. What is the area of rectangle PQRS?
Answer» In the figure given, PR = 22 cm, SN = MQ = 3 cm. What is the area of rectangle PQRS?

Discussion

30.	If resistors decrease current , then why value of I Remains unchanged means before undergoing value off I is i1 then after undergoing resistor same i1
Answer» If resistors decrease current , then why value of I Remains unchanged means before undergoing value off I is i1 then after undergoing resistor same i1

Discussion

31.	What causes glaucoma?
Answer» What causes glaucoma?

Discussion

32.	An object is placed perpendicular to the principal axis of a convex lens of focal length 10 cm at a distance of 20 cm from the lens. Find the position of the image. What is the magnification of the object? [4 MARKS]
Answer» An object is placed perpendicular to the principal axis of a convex lens of focal length 10 cm at a distance of 20 cm from the lens. Find the position of the image. What is the magnification of the object? [4 MARKS]

Discussion

33.	What is the value of g when the object is at maximum height?
Answer» What is the value of g when the object is at maximum height?

Discussion

34.	63. In a galvanometer 5% of the total current in thecircuit passes through it. If the resistance of thegalvanometer is G, the shunt resistance 'S' connectedto the galvanometer is4) G/201) 19 G2) G/193) 20 G
Answer» 63. In a galvanometer 5% of the total current in thecircuit passes through it. If the resistance of thegalvanometer is G, the shunt resistance 'S' connectedto the galvanometer is4) G/201) 19 G2) G/193) 20 G

Discussion

35.	when the light rays passes through the convex mirror, why does the reflected ray pass outward or moves away from the principle of focus
Answer» when the light rays passes through the convex mirror, why does the reflected ray pass outward or moves away from the principle of focus

Discussion

36.	two particles a and b having charges 2 c and -4c are fixed at a sepration of 20 cm.locate points on line ab in which electric field is zero
Answer» two particles a and b having charges 2 c and -4c are fixed at a sepration of 20 cm.locate points on line ab in which electric field is zero

Discussion

37.	Electric supply of a house is through a 10 A fuse. When a 2000 W heater is used in this house, how many 100 W bulbs can be used simultaneously? The supply is at 220 V, and the heater and the bulbs are rated for 220 V.
Answer» Electric supply of a house is through a 10 A fuse. When a 2000 W heater is used in this house, how many 100 W bulbs can be used simultaneously? The supply is at 220 V, and the heater and the bulbs are rated for 220 V.

Discussion

38.	When the volume of lungs increases then how the pressure decreases and when the volume of lungs decreases how the pressure increases?
Answer» When the volume of lungs increases then how the pressure decreases and when the volume of lungs decreases how the pressure increases?

Discussion

39.	The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?
Answer» The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

Discussion

40.	An insulated copper wire is wound on a soft iron core. Current is passed through the coil such that at end ‘A’ the current flows anti- clockwise and a magnetic compass needle placed at other end ‘B’ of the coil. i) If soft iron core is replaced by a cardboard tube, what will be the effect on the magnetic needle? ii) What happens to the magnetic needle if the current is stopped?
Answer» An insulated copper wire is wound on a soft iron core. Current is passed through the coil such that at end ‘A’ the current flows anti- clockwise and a magnetic compass needle placed at other end ‘B’ of the coil. i) If soft iron core is replaced by a cardboard tube, what will be the effect on the magnetic needle? ii) What happens to the magnetic needle if the current is stopped?

40.

An insulated copper wire is wound on a soft iron core. Current is passed through the coil such that at end ‘A’ the current flows anti- clockwise and a magnetic compass needle placed at other end ‘B’ of the coil. i) If soft iron core is replaced by a cardboard tube, what will be the effect on the magnetic needle? ii) What happens to the magnetic needle if the current is stopped?

Answer»

An insulated copper wire is wound on a soft iron core. Current is passed through the coil such that at end ‘A’ the current flows anti- clockwise and a magnetic compass needle placed at other end ‘B’ of the coil.

i) If soft iron core is replaced by a cardboard tube, what will be the effect on the magnetic needle?

ii) What happens to the magnetic needle if the current is stopped?

Discussion

41.	In fig shows a system of four pulleys. The upper two puleys are fixed and the lower two are movable. (a) Draw a string around the pulleys.Also show the point of application and direction in which the effort E is applied. (b) What is the velocity ratio of the system ? (c) How are load and effort of the pulley system related ? (d) What assumption do you make in arriving at your answer in part (c) ?
Answer» In fig shows a system of four pulleys. The upper two puleys are fixed and the lower two are movable. (a) Draw a string around the pulleys.Also show the point of application and direction in which the effort E is applied. (b) What is the velocity ratio of the system ? (c) How are load and effort of the pulley system related ? (d) What assumption do you make in arriving at your answer in part (c) ?

41.

In fig shows a system of four pulleys. The upper two puleys are fixed and the lower two are movable. (a) Draw a string around the pulleys.Also show the point of application and direction in which the effort E is applied. (b) What is the velocity ratio of the system ? (c) How are load and effort of the pulley system related ? (d) What assumption do you make in arriving at your answer in part (c) ?

Answer»

In fig shows a system of four pulleys. The upper two puleys are fixed and the lower two are movable.

(a) Draw a string around the pulleys.Also show the point of application and direction in which the effort E is applied.

(b) What is the velocity ratio of the system ?

(c) How are load and effort of the pulley system related ?

(d) What assumption do you make in arriving at your answer in part (c) ?

Discussion

42.	A small body is initially at a distance r from the centre of earth. r is greater than the radius of the earth. If it takes W joules of work to move the body from this position to another position at a distance 2r measured from the centre of earth, then how many joules would be required to move it from this position to a new position at a distance of 3r from the centre of the earth.
Answer» A small body is initially at a distance $r$ from the centre of earth. $r$ is greater than the radius of the earth. If it takes $W$ $joules$ of work to move the body from this position to another position at a distance $2 r$ measured from the centre of earth, then how many $joules$ would be required to move it from this position to a new position at a distance of $3 r$ from the centre of the earth.

Discussion

43.	It is desired to make a converging achromatic combination of mean focal length 50 cm by using two lenses of materials A and B. If the dispersive powers of A and B are in ratio 1:2. The focal length of the lens are
Answer» It is desired to make a converging achromatic combination of mean focal length $50 cm$ by using two lenses of materials $A$ and $B .$ If the dispersive powers of $A$ and $B$ are in ratio $1 : 2.$ The focal length of the lens are

Discussion

44.	In a DC generator, the induced e.m.f. in the armature is:
Answer» In a DC generator, the induced e.m.f. in the armature is:

Discussion

45.	A student uses a lens of focal length 40 cm and another of -20 cm. Write the nature and power of each lens.
Answer» A student uses a lens of focal length 40 cm and another of -20 cm. Write the nature and power of each lens.

Discussion

46.	What is meant by conductors and insulators ? Give two examples of conductors and two of insulators.
Answer» What is meant by conductors and insulators ? Give two examples of conductors and two of insulators.

Discussion

47.	Notice the use of words repeated in lines such as these:i) On pads of velvet quiet,In his quiet rage.ii) And stares with his brilliant eyes,At the brilliant stars.What do you think is the effect of this repetition?
Answer» Notice the use of words repeated in lines such as these: i) On pads of velvet quiet, In his quiet rage. ii) And stares with his brilliant eyes, At the brilliant stars. What do you think is the effect of this repetition?

47.

Notice the use of words repeated in lines such as these:i) On pads of velvet quiet,In his quiet rage.ii) And stares with his brilliant eyes,At the brilliant stars.What do you think is the effect of this repetition?

Answer»

Notice the use of words repeated in lines such as these:

i) On pads of velvet quiet,

In his quiet rage.

ii) And stares with his brilliant eyes,

At the brilliant stars.

What do you think is the effect of this repetition?

Discussion

48.	If frequency of light not chanfe why color change through prism and frequency relates to colour
Answer» If frequency of light not chanfe why color change through prism and frequency relates to colour

Discussion

49.	A 3 cm high object is placed at a distance of 80 cm from a concave lens of focal length 20 cm. Find the position and size of the image.
Answer» A 3 cm high object is placed at a distance of 80 cm from a concave lens of focal length 20 cm. Find the position and size of the image.

Discussion

50.	Write the condition required for a circuit to be a closed circuit.
Answer» Write the condition required for a circuit to be a closed circuit.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

a charge q is placed inside a horizontal circle of radius r, and a hemisphere of this radius is erected about the charge.Compute the electric flux through the closed surface that consists of the hemisphere and the planar circle.Do not use Gauss Law.

A beam with overhang supports two concentrated loads P and Q as shown in the figure. The ratio of Q/P, so that deflection at D will be zero is_____4

A point source of light is kept at adistance of 15cm from a converging lens on its optical axis.A sharp image is formed on the screen which is placed at a distance 20cm from lens find the focal length of lens

Which property of sound helps the brain to interpret the frequency of a sound wave?

The moment of inertia of a body moving with angular velocity w decreases from I to I/3 without any external torque. Calculate the new average velocity of bo

A point charge produces an electric field of magnitude 5.0Nc^-1 at a distance 40cm it . What is the magnitude of charge

15.find the magnetic field at the centre of the loop O shown in the figure

A ray light incident on a lens parallel to its principal axis, after refraction passes through or appears to come from : (a) its first focus (b) its optical centre (c) its second focus (d) the centre of curvation of its second surface.

The relation between current in a conductor and time is shown in the figure.(iii) If the resistance of the conductor is R then the total heat dissipated across resistance R is​​​​​​​[1 Mark]

Question 19Which part of the eye gets affected if someone is suffering from cataract? How is it treated?

Center of Mass

A wire of resistance 10Ω is stretched such that its area becomes 13rd and its volume remains constant. What will be the new resistance?

Mention names of two phenomenon due to which rainbow is formed.

An object is midway between the lens and the mirror as shown. The mirror's radius of curvature is 20.0 cm and the lens has a focal length of −503 cm. Considering only the rays that leaves the object travelling first towards the mirror, find the overall magnification.

What is the nature of the image formed in: Concave lens Convex lensAlso give one use of each lens.

Which graph represents the relation between resistance and area of a conductor when other parameters are constant?

Around a current carrying wire, there is a ___.

A student has obtained the image of a distant object with a concave mirror to determine its focal length. If he has selected a well - illuminated red building as object, which of the following correctly describes the features of the image formed?

an inductor l=0.03 henry and a resistor r=150 ohm are connect in series to a battery of 15 v emf ina circuit shown below the key k1 has been kept closed for a long time then at t=0 k1 is opened and key k2 is closed simultaneously At t=1ms the current in the circuit will be

A child drops a toy from the top of a building, it takes 1 s to reach the ground. Find the height of the building and the average speed of the toy respectively.(Take g = 10 ms−2)

Tidal energy is harnessed by constructing

why focal length of convex mirror and convex lens is '+' ( positive ) explain with the help of diagram if needed .

what equal charge would have to be placed on earth and moon to neutralize their gravitational attraction given mass of earth=10 ki power25kg and mass of moon =10 ki power 23kg

35. Figure shows the variation of electric field intensity E versus distance x. What is the potential difference betweenthe points at x = 2 m and at x = 6 m from O?

Two wires of the same material and same length have radii r1 and r2 respectively.Compare 1. Their resistance 2. Their specific resistance

The correct relation between α (ratio of collector current to emitter current) and β (ratio of collector current to base current) of a transistor is :

In the figure given, PR = 22 cm, SN = MQ = 3 cm. What is the area of rectangle PQRS?

If resistors decrease current , then why value of I Remains unchanged means before undergoing value off I is i1 then after undergoing resistor same i1

What causes glaucoma?

An object is placed perpendicular to the principal axis of a convex lens of focal length 10 cm at a distance of 20 cm from the lens. Find the position of the image. What is the magnification of the object? [4 MARKS]

What is the value of g when the object is at maximum height?

63. In a galvanometer 5% of the total current in thecircuit passes through it. If the resistance of thegalvanometer is G, the shunt resistance 'S' connectedto the galvanometer is4) G/201) 19 G2) G/193) 20 G

when the light rays passes through the convex mirror, why does the reflected ray pass outward or moves away from the principle of focus

two particles a and b having charges 2 c and -4c are fixed at a sepration of 20 cm.locate points on line ab in which electric field is zero

Electric supply of a house is through a 10 A fuse. When a 2000 W heater is used in this house, how many 100 W bulbs can be used simultaneously? The supply is at 220 V, and the heater and the bulbs are rated for 220 V.

When the volume of lungs increases then how the pressure decreases and when the volume of lungs decreases how the pressure increases?

The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

It is desired to make a converging achromatic combination of mean focal length 50 cm by using two lenses of materials A and B. If the dispersive powers of A and B are in ratio 1:2. The focal length of the lens are

In a DC generator, the induced e.m.f. in the armature is:

A student uses a lens of focal length 40 cm and another of -20 cm. Write the nature and power of each lens.

What is meant by conductors and insulators ? Give two examples of conductors and two of insulators.

Notice the use of words repeated in lines such as these:i) On pads of velvet quiet,In his quiet rage.ii) And stares with his brilliant eyes,At the brilliant stars.What do you think is the effect of this repetition?

If frequency of light not chanfe why color change through prism and frequency relates to colour

A 3 cm high object is placed at a distance of 80 cm from a concave lens of focal length 20 cm. Find the position and size of the image.

Write the condition required for a circuit to be a closed circuit.

The relation between current in a conductor and time is shown in the figure.(iii) If the resistance of the conductor is R then the total heat dissipated across resistance R is[1 Mark]