16569 + Interview Questions in Physics Page 12 InterviewSolution

551.	Two small conducting spheres of radius R and 2R have charges 40 μ C and -10 μ C respectively, placed at a dis†an ce r from each other experience a force of magnitude F_1. If they are brought in contact and separated by same dis†an ce r, they experience force of magnitude F_2. The ratio of F_1 to F_2 is (r>>R) (1) 1:1 (2) 2:1 (3) 4:3 (4) 3:4
Answer» Two small conducting spheres of radius R and 2R have charges 40 μ C and -10 μ C respectively, placed at a dis†an ce r from each other experience a force of magnitude F_1. If they are brought in contact and separated by same dis†an ce r, they experience force of magnitude F_2. The ratio of F_1 to F_2 is (r>>R) (1) 1:1 (2) 2:1 (3) 4:3 (4) 3:4

Discussion

552.	white light is incident on the interface of glass and air. If green light is just totally internally reflected then the emerging ray in air contains (1) Yellow, orange, red (2) Violet, indigo, blue (3) All colours (4) All colours except green
Answer» white light is incident on the interface of glass and air. If green light is just totally internally reflected then the emerging ray in air contains (1) Yellow, orange, red (2) Violet, indigo, blue (3) All colours (4) All colours except green

Discussion

553.	35.Explanations of magnetic force on a current carrying conductor.
Answer» 35.Explanations of magnetic force on a current carrying conductor.

Discussion

554.	Define the term energy and state its S.I. unit.
Answer» Define the term energy and state its S.I. unit.

Discussion

555.	Accordingly to Michael Faraday, In a generator, strength of the induced e.m.f does not depend on
Answer» Accordingly to Michael Faraday, In a generator, strength of the induced e.m.f does not depend on

Discussion

556.	What do we mean by Voltage drop?
Answer» What do we mean by Voltage drop?

Discussion

557.	Is the relative strength of Electromagnetic and Gravitational forces 10^-37?
Answer» Is the relative strength of Electromagnetic and Gravitational forces 10^-37?

Discussion

558.	3 equal.weights of mass 2 kg each are hnging on a string passing over a fixed frictionless pulleyThe tendion in string AB
Answer» 3 equal.weights of mass 2 kg each are hnging on a string passing over a fixed frictionless pulley The tendion in string AB

Discussion

559.	An equilateral prism deviates a ray through 45^° for twoahgles of incidence differing by 20^° . The refractive index of theprism is: "
Answer» An equilateral prism deviates a ray through 45^° for twoahgles of incidence differing by 20^° . The refractive index of theprism is: "

Discussion

560.	A plane electromagnetic wave of frequency 500 MHz is travelling in vacuum along y-direction. At a particular point in space and time, →B=8.0×10−8^z T. The electric field at this point is:(Speed of light in vacuum =3×108 ms−1. Assume ^x,^y,^z are unit vectors along x,y and z directions.)
Answer» A plane electromagnetic wave of frequency $500 MHz$ is travelling in vacuum along $y$ -direction. At a particular point in space and time, $\to B = 8.0 \times 10^{- 8}^z T$ . The electric field at this point is: (Speed of light in vacuum $= 3 \times 10^{8} {ms}^{- 1}$ . Assume $^x,^y,^z$ are unit vectors along $x, y$ and $z$ directions.)

Discussion

561.	A 5 V battery and a 2 V battery are connected to the resistances as shown. The current in the 10 Ω resistor is :
Answer» A $5 V$ battery and a $2 V$ battery are connected to the resistances as shown. The current in the $10 Ω$ resistor is :

Discussion

562.	Name the characteristic of the sound affected due to a change in its following quantities:(a) Amplitude(b) Frequency
Answer» Name the characteristic of the sound affected due to a change in its following quantities: (a) Amplitude (b) Frequency

Discussion

563.	Find the potential difference between A and B (VA−VB) for the given circuit
Answer» Find the potential difference between A and B $(V_{A} - V_{B})$ for the given circuit

Discussion

564.	What kind of image will you get if an object is placed between ′C′ and ′f′ for a concave mirror?
Answer» What kind of image will you get if an object is placed between $^{'} C^{'}$ and $^{'} f^{'}$ for a concave mirror?

Discussion

565.	Which of the given statements is true regarding a hot and cold body?
Answer» Which of the given statements is true regarding a hot and cold body?

Discussion

566.	Answer the following questions. (a) Why is the direction of the current in an electric motor reversed after every half round? (b) How can the strength of an electro-magnet be increased? (c) What is the principle of the electric motor? (d) Why is there a key in an electrical circuit? (e) Is the mechanism of a shirt button like that of the key in an electric circuit?
Answer» Answer the following questions. (a) Why is the direction of the current in an electric motor reversed after every half round? (b) How can the strength of an electro-magnet be increased? (c) What is the principle of the electric motor? (d) Why is there a key in an electrical circuit? (e) Is the mechanism of a shirt button like that of the key in an electric circuit?

566.

Answer the following questions. (a) Why is the direction of the current in an electric motor reversed after every half round? (b) How can the strength of an electro-magnet be increased? (c) What is the principle of the electric motor? (d) Why is there a key in an electrical circuit? (e) Is the mechanism of a shirt button like that of the key in an electric circuit?

Answer»

Answer the following questions.

(a) Why is the direction of the current in an electric motor reversed after every half round?

(b) How can the strength of an electro-magnet be increased?

(c) What is the principle of the electric motor?

(d) Why is there a key in an electrical circuit?

(e) Is the mechanism of a shirt button like that of the key in an electric circuit?

Discussion

567.	Find the odd one.
Answer» Find the odd one.

Discussion

568.	The wavelength of red coloured light is almost than that of blue colour. a) triple b) double C) one fourth d) one third
Answer» The wavelength of red coloured light is almost than that of blue colour. a) triple b) double C) one fourth d) one third

Discussion

569.	in a regular polygon of n sides of each corner at a distance r from centre identical charges q are placed at (n-1)corner .the electric field of centre
Answer» in a regular polygon of n sides of each corner at a distance r from centre identical charges q are placed at (n-1)corner .the electric field of centre

Discussion

570.	What will be the value of focal length when object is placed at Infinity in convex mirror (positive or negative)?
Answer» What will be the value of focal length when object is placed at Infinity in convex mirror (positive or negative)?

Discussion

571.	The latent heat of vaporization of a substance is always ______________.
Answer» The latent heat of vaporization of a substance is always ______________.

Discussion

572.	A ray of light is incident on a transparent glass slab of refractive index 1.62 from the air with refractive index 1. If the reflected and refracted rays are mutually perpendicular, what is the angle of incidence?
Answer» A ray of light is incident on a transparent glass slab of refractive index $1.62$ from the air with refractive index $1$ . If the reflected and refracted rays are mutually perpendicular, what is the angle of incidence?

Discussion

573.	Can we make black light?
Answer» Can we make black light?

Discussion

574.	a cell can be balanced against 110 cm and hundred CM of potentiometer wire respectively with and without being short circuited through a resistance of 10 ohm . its internal resistance is-1)Zero 2)1 ohm 3)0.5 ohm 4)2 ohm
Answer» a cell can be balanced against 110 cm and hundred CM of potentiometer wire respectively with and without being short circuited through a resistance of 10 ohm . its internal resistance is- 1)Zero 2)1 ohm 3)0.5 ohm 4)2 ohm

Discussion

575.	A jack screw is provided with a long arm. Explain why ?
Answer» A jack screw is provided with a long arm. Explain why ?

Discussion

576.	A thermodynamic process, 200 J of heat is given to a gas and 100 J of work is also done on it. The change in internal energy of the gas is. A .
Answer» A thermodynamic process, 200 J of heat is given to a gas and 100 J of work is also done on it. The change in internal energy of the gas is. A .

Discussion

577.	Why are optical telescopes located in uninhabited places on mountains?
Answer» Why are optical telescopes located in uninhabited places on mountains?

Discussion

578.	Find the emf induced in the coil if it were positioned such that its plane contains the axis of the solenoid.
Answer» Find the emf induced in the coil if it were positioned such that its plane contains the axis of the solenoid.

Discussion

579.	The human eye possesses the power of accommodation. This is the power to : (a) alter the diameter of the pupil as the intensity of light changes (b) distinguish between lights of different colours (c) focus on objects at different distances (d) decide which of the two objects is closer.
Answer» The human eye possesses the power of accommodation. This is the power to : (a) alter the diameter of the pupil as the intensity of light changes (b) distinguish between lights of different colours (c) focus on objects at different distances (d) decide which of the two objects is closer.

Discussion

580.	64. Integration of 1/6xdx
Answer» 64. Integration of 1/6xdx

Discussion

581.	Draw a schematic diagram of solar thermal electric energy generation.
Answer» Draw a schematic diagram of solar thermal electric energy generation.

Discussion

582.	Why does the cord of an electrical heater not glow while the heating elements does
Answer» Why does the cord of an electrical heater not glow while the heating elements does

Discussion

583.	An object is placed at 25 cm in front of a convex lens. Its image is formed at 75 cm from the lens on the same side as the object. Find the power of the lens?
Answer» An object is placed at $25 c m$ in front of a convex lens. Its image is formed at $75 c m$ from the lens on the same side as the object. Find the power of the lens?

Discussion

584.	Coal gas is a mixture of
Answer» Coal gas is a mixture of

Discussion

585.	The device which measures the electric potential difference between two points is called as _____.
Answer» The device which measures the electric potential difference between two points is called as _____.

Discussion

586.	Question 2Which of the following terms does not represent electrical power in a circuit?(a) I2R(b) IR2(c) VI(d) V2R
Answer» Question 2 Which of the following terms does not represent electrical power in a circuit? (a) $I^{2} R$ (b) $I R^{2}$ (c) VI (d) $\frac{V^{2}}{R}$

Discussion

587.	Write the difference between heat and temperature.
Answer» Write the difference between heat and temperature.

Discussion

588.	A compound microscope consists of 2 lens of focal length 0.8 and 3 cm.If the object is 0.85 cm from objective and final image is 24 cm from eye piece then what is the magnifying power of the microscope?
Answer» A compound microscope consists of 2 lens of focal length 0.8 and 3 cm.If the object is 0.85 cm from objective and final image is 24 cm from eye piece then what is the magnifying power of the microscope?

Discussion

589.	A road of width 20m forms an arc of radius 15m , its outer edge is 2m higher than its inner edge.Calculate for what velocity the road is banked ?
Answer» A road of width 20m forms an arc of radius 15m , its outer edge is 2m higher than its inner edge.Calculate for what velocity the road is banked ?

Discussion

590.	Make a battery from four sliced lemon pieces and test it with a LED by drawing a circuit.
Answer» Make a battery from four sliced lemon pieces and test it with a LED by drawing a circuit.

Discussion

591.	Blue colour of the sky is due to
Answer» Blue colour of the sky is due to

Discussion

592.	A convex lens of focal length f produces a real image x times the size of an object then what will be the distance of the object from the lens?
Answer» A convex lens of focal length f produces a real image $x$ times the size of an object then what will be the distance of the object from the lens?

Discussion

593.	In a L−R decay circuit, the initial current at t=0 is I. The total charge that has flown through the resistor till the energy in the inductor has reduced to one-fourth of its initial value is
Answer» In a $L - R$ decay circuit, the initial current at $t = 0$ is $I$ . The total charge that has flown through the resistor till the energy in the inductor has reduced to one-fourth of its initial value is

Discussion

594.	What is meant by momentum? What are the similarities and differences between linear and angular momentum?
Answer» What is meant by momentum? What are the similarities and differences between linear and angular momentum?

Discussion

595.	why gauge pressure is positive negative and
Answer» why gauge pressure is positive negative and

Discussion

596.	What is Coriolis Force?
Answer» What is Coriolis Force?

Discussion

597.	find the magnetic intensity H at the centre of a long solenoid having n turns per unit length and carrying current i when a copper rod is inserted in the solenoid. why is their no effect of rod in this
Answer» find the magnetic intensity H at the centre of a long solenoid having n turns per unit length and carrying current i when a copper rod is inserted in the solenoid. why is their no effect of rod in this

Discussion

598.	When an object is placed at a distance of 50 cm from a concave spherical mirror, the magnification produced is, -12 . Where should the object be placed to get a magnification of, - 15 ?
Answer» When an object is placed at a distance of 50 cm from a concave spherical mirror, the magnification produced is, - $\frac{1}{2}$ . Where should the object be placed to get a magnification of, - $\frac{1}{5}$ ?

Discussion

599.

To study the dependence of current (I) on the potential difference (V) across a resistor, the following observations were made by four students A, B, C and D. Student Reading No. 1 Reading No. 2 Reading No. 3 A V = 0.5 V I = 0.1 A V = 1.0 V I = 0.2 A V = 1.5 V I = 0.3 A B V = 0.8 V I = 0.4 A V = 1.6 V I = 0.8 A V = 2.4 V I = 1.2 A C V = 1.0 V I = 0.5 A V = 1.2 V I = 1.4 A V = 1.4 V I = 1.0 A D V = 2.4 V I = 0.8 A V = 2.7 V I = 0.9 A V = 3.0 V I = 1.0 A The teacher found that one of the students has made wrong observations. The student who made the mistake is:(1) A(2) B(3) C(4) D

Answer» To study the dependence of current (I) on the potential difference (V) across a resistor, the following observations were made by four students A, B, C and D.

Student	Reading No. 1	Reading No. 2	Reading No. 3
A	V = 0.5 V I = 0.1 A	V = 1.0 V I = 0.2 A	V = 1.5 V I = 0.3 A
B	V = 0.8 V I = 0.4 A	V = 1.6 V I = 0.8 A	V = 2.4 V I = 1.2 A
C	V = 1.0 V I = 0.5 A	V = 1.2 V I = 1.4 A	V = 1.4 V I = 1.0 A
D	V = 2.4 V I = 0.8 A	V = 2.7 V I = 0.9 A	V = 3.0 V I = 1.0 A

The teacher found that one of the students has made wrong observations. The student who made the mistake is:

(1) A

(2) B

(3) C

(4) D

Discussion

600.	A carnot engine is designed to operate between temperature 480K and 300K if the engine actually produce 1.2J of mechanical energy per calorie of heat absorbed then the ratio of actual efficiency and theoretical efficiency is (1cal=4.2J) 1.16/21 2.12/21 3.3/4 4.3/
Answer» A carnot engine is designed to operate between temperature 480K and 300K if the engine actually produce 1.2J of mechanical energy per calorie of heat absorbed then the ratio of actual efficiency and theoretical efficiency is (1cal=4.2J) 1.16/21 2.12/21 3.3/4 4.3/

Discussion

Explore topic-wise InterviewSolutions in .

white light is incident on the interface of glass and air. If green light is just totally internally reflected then the emerging ray in air contains (1) Yellow, orange, red (2) Violet, indigo, blue (3) All colours (4) All colours except green

35.Explanations of magnetic force on a current carrying conductor.

Define the term energy and state its S.I. unit.

Accordingly to Michael Faraday, In a generator, strength of the induced e.m.f does not depend on

What do we mean by Voltage drop?

Is the relative strength of Electromagnetic and Gravitational forces 10^-37?

3 equal.weights of mass 2 kg each are hnging on a string passing over a fixed frictionless pulleyThe tendion in string AB

An equilateral prism deviates a ray through 45^° for twoahgles of incidence differing by 20^° . The refractive index of theprism is: "

A plane electromagnetic wave of frequency 500 MHz is travelling in vacuum along y-direction. At a particular point in space and time, →B=8.0×10−8^z T. The electric field at this point is:(Speed of light in vacuum =3×108 ms−1. Assume ^x,^y,^z are unit vectors along x,y and z directions.)

A 5 V battery and a 2 V battery are connected to the resistances as shown. The current in the 10 Ω resistor is :

Name the characteristic of the sound affected due to a change in its following quantities:(a) Amplitude(b) Frequency

Find the potential difference between A and B (VA−VB) for the given circuit

What kind of image will you get if an object is placed between ′C′ and ′f′ for a concave mirror?

Which of the given statements is true regarding a hot and cold body?

Find the odd one.

The wavelength of red coloured light is almost than that of blue colour. a) triple b) double C) one fourth d) one third

in a regular polygon of n sides of each corner at a distance r from centre identical charges q are placed at (n-1)corner .the electric field of centre

What will be the value of focal length when object is placed at Infinity in convex mirror (positive or negative)?

The latent heat of vaporization of a substance is always ______________.

A ray of light is incident on a transparent glass slab of refractive index 1.62 from the air with refractive index 1. If the reflected and refracted rays are mutually perpendicular, what is the angle of incidence?

Can we make black light?

a cell can be balanced against 110 cm and hundred CM of potentiometer wire respectively with and without being short circuited through a resistance of 10 ohm . its internal resistance is-1)Zero 2)1 ohm 3)0.5 ohm 4)2 ohm

A jack screw is provided with a long arm. Explain why ?

A thermodynamic process, 200 J of heat is given to a gas and 100 J of work is also done on it. The change in internal energy of the gas is. A .

Why are optical telescopes located in uninhabited places on mountains?

Find the emf induced in the coil if it were positioned such that its plane contains the axis of the solenoid.

The human eye possesses the power of accommodation. This is the power to : (a) alter the diameter of the pupil as the intensity of light changes (b) distinguish between lights of different colours (c) focus on objects at different distances (d) decide which of the two objects is closer.

64. Integration of 1/6xdx

Draw a schematic diagram of solar thermal electric energy generation.

Why does the cord of an electrical heater not glow while the heating elements does

An object is placed at 25 cm in front of a convex lens. Its image is formed at 75 cm from the lens on the same side as the object. Find the power of the lens?

Coal gas is a mixture of

The device which measures the electric potential difference between two points is called as _____.

Question 2Which of the following terms does not represent electrical power in a circuit?(a) I2R(b) IR2(c) VI(d) V2R

Write the difference between heat and temperature.

A compound microscope consists of 2 lens of focal length 0.8 and 3 cm.If the object is 0.85 cm from objective and final image is 24 cm from eye piece then what is the magnifying power of the microscope?

A road of width 20m forms an arc of radius 15m , its outer edge is 2m higher than its inner edge.Calculate for what velocity the road is banked ?

Make a battery from four sliced lemon pieces and test it with a LED by drawing a circuit.

Blue colour of the sky is due to

A convex lens of focal length f produces a real image x times the size of an object then what will be the distance of the object from the lens?

In a L−R decay circuit, the initial current at t=0 is I. The total charge that has flown through the resistor till the energy in the inductor has reduced to one-fourth of its initial value is

What is meant by momentum? What are the similarities and differences between linear and angular momentum?

why gauge pressure is positive negative and

What is Coriolis Force?

find the magnetic intensity H at the centre of a long solenoid having n turns per unit length and carrying current i when a copper rod is inserted in the solenoid. why is their no effect of rod in this

When an object is placed at a distance of 50 cm from a concave spherical mirror, the magnification produced is, -12 . Where should the object be placed to get a magnification of, - 15 ?

A carnot engine is designed to operate between temperature 480K and 300K if the engine actually produce 1.2J of mechanical energy per calorie of heat absorbed then the ratio of actual efficiency and theoretical efficiency is (1cal=4.2J) 1.16/21 2.12/21 3.3/4 4.3/