16569 + Interview Questions in Physics Page 9 InterviewSolution

401.	A ball of mass 50 g moving at a speed of 2.0 m/s strikes a plane surface at an angle of incidence 45∘ . The ball is reflected by the plane at equal angle of reflection with the same speed. Calculate (a) the magnitude of the change in momentum of the ball (b) the change in the magnitude of the momentum of the ball.
Answer» A ball of mass 50 g moving at a speed of 2.0 m/s strikes a plane surface at an angle of incidence $45^{\circ}$ . The ball is reflected by the plane at equal angle of reflection with the same speed. Calculate (a) the magnitude of the change in momentum of the ball (b) the change in the magnitude of the momentum of the ball.

Discussion

402.	A block and tackle system has 5 pulleys. If an effort of 1000 N is needed in the downward direction to raise a load of 4500 N, calculate the efficiency(%) of the system.90
Answer» A block and tackle system has $5$ pulleys. If an effort of $1000 N$ is needed in the downward direction to raise a load of $4500 N$ , calculate the efficiency( $%$ ) of the system. 90

Discussion

403.	To find the resultant resistance of two resistors when connected in series, a student arranged the various components according to the circuit shown alongside:The student, however, did not succeed in his objective. Which of the following mistake has been made by the student in setting up the circuit?(1) position of voltmeter is wrong(2) position of ammeter is wrong(3) terminals of voltmeter are wrongly connected(4) terminals of ammeter are wrongly connected
Answer» To find the resultant resistance of two resistors when connected in series, a student arranged the various components according to the circuit shown alongside: The student, however, did not succeed in his objective. Which of the following mistake has been made by the student in setting up the circuit? (1) position of voltmeter is wrong (2) position of ammeter is wrong (3) terminals of voltmeter are wrongly connected (4) terminals of ammeter are wrongly connected

Discussion

404.	A truck driver can load oil drums into the back of the truck by pushing them up a sloping plank or by lifting them directly. Each drum has a mass of 80 kg, the plank is 3m long and the back of the truck is 0.8m above the ground. How much force would be needed to lift a drum into the truck directly, without using the plank? [Take g =10m/s2]
Answer» A truck driver can load oil drums into the back of the truck by pushing them up a sloping plank or by lifting them directly. Each drum has a mass of 80 kg, the plank is 3m long and the back of the truck is 0.8m above the ground. How much force would be needed to lift a drum into the truck directly, without using the plank? [Take g =10m/s²]

Discussion

405.	Which lens has more power : a thick lens or a thin lens ?
Answer» Which lens has more power : a thick lens or a thin lens ?

Discussion

406.	How magnetic field line are responsible for attraction and repulsion between two magnets and why??
Answer» How magnetic field line are responsible for attraction and repulsion between two magnets and why??

Discussion

407.	___ is the linear distance between the pole and principal axis.
Answer» ___ is the linear distance between the pole and principal axis.

Discussion

408.	If an object is placed at a distance of 30 cm and the image is formed at a distance of 10 cm on the same side of the lens, then find the focal length of the lens used.
Answer» If an object is placed at a distance of $30 c m$ and the image is formed at a distance of $10 c m$ on the same side of the lens, then find the focal length of the lens used.

Discussion

409.	What is a prism? With the help of a diagram of a principal section of a prism, indicate its refracting surfaces, refracting angle and base.
Answer» What is a prism? With the help of a diagram of a principal section of a prism, indicate its refracting surfaces, refracting angle and base.

Discussion

410.	Why does the sun appear reddish early in the morning
Answer» Why does the sun appear reddish early in the morning

Discussion

411.	Who first discovered the relationship between electricity and magnetism?
Answer» Who first discovered the relationship between electricity and magnetism?

Discussion

412.	A truck weighing 1000 kgf changes its speed from 36 km per hour in 2 minutes. Calculate: 1) The work done by the engine and its power
Answer» A truck weighing 1000 kgf changes its speed from 36 km per hour in 2 minutes. Calculate: 1) The work done by the engine and its power

Discussion

413.	Two long coaxial solenoid, each of length l. The outer solenoid has an area of cross section A1 and number of turns /length n1. The corresponding value of the inner solenoid are A2 and n2. Write the expression for self inductance L1 L2 of the two coils and their mutual inductance M. Hence show that M
Answer» Two long coaxial solenoid, each of length l. The outer solenoid has an area of cross section A1 and number of turns /length n1. The corresponding value of the inner solenoid are A2 and n2. Write the expression for self inductance L1 L2 of the two coils and their mutual inductance M. Hence show that M

Discussion

414.	If the magnification produced by the lens is -0.5,the correct statement is:
Answer» If the magnification produced by the lens is -0.5,the correct statement is:

Discussion

415.	A piece of wire of resistance 4 ohm is bent through 180° at its mid point and the two halves are twisted together, then find the resistance.
Answer» A piece of wire of resistance 4 ohm is bent through 180° at its mid point and the two halves are twisted together, then find the resistance.

Discussion

416.	According to the "New Cartesian Sign Convention" for mirrors, what sign has been given to the focal length of : (i) a concave mirror ? (ii) a convex mirror ?
Answer» According to the "New Cartesian Sign Convention" for mirrors, what sign has been given to the focal length of : (i) a concave mirror ? (ii) a convex mirror ?

Discussion

417.	ntA short solenoid of length 4 cm, radius 2 cm and 100 turns is placed inside and on the axis of a long solenoid of length 80 cm and 1500 turns. A current of 3 A flows through the short solenoid. The mutual inductance of two solenoid isn
Answer» ntA short solenoid of length 4 cm, radius 2 cm and 100 turns is placed inside and on the axis of a long solenoid of length 80 cm and 1500 turns. A current of 3 A flows through the short solenoid. The mutual inductance of two solenoid isn

Discussion

418.	Characteristic property of light responsible for the blue colour of the sky is
Answer» Characteristic property of light responsible for the blue colour of the sky is

Discussion

419.	What are the ammeter (A) and voltmeter (V) readings in the circuit?
Answer» What are the ammeter (A) and voltmeter (V) readings in the circuit?

419.

What are the ammeter (A) and voltmeter (V) readings in the circuit?

Answer»

What are the ammeter (A) and voltmeter (V) readings in the circuit?

Discussion

420.	how light travel in space with speed of 3×10^8m/s ?
Answer» how light travel in space with speed of 3×10^8m/s ?

Discussion

421.	Find the angular magnification in this case. (image at infinity)
Answer» Find the angular magnification in this case. (image at infinity)

Discussion

422.	Question 14An observer 1.5 m tall is 20.5 m away from a tower 22 m high. Determine the angle of elevation of the top of the tower from the eye of the observer.
Answer» Question 14 An observer 1.5 m tall is 20.5 m away from a tower 22 m high. Determine the angle of elevation of the top of the tower from the eye of the observer.

Discussion

423.	a wire of one metre under a certain initial tension emits a sound of fundamental frequency 256 Hz when the tension is increased by 1 kg wt the frequency of the fundamental node increases to 320 Hz. The initial tension is(1) 3/4 kg wt(2)16/9 kg wt () 4/3 kg wt (4) 20/9 kg wt
Answer» a wire of one metre under a certain initial tension emits a sound of fundamental frequency 256 Hz when the tension is increased by 1 kg wt the frequency of the fundamental node increases to 320 Hz. The initial tension is(1) 3/4 kg wt(2)16/9 kg wt () 4/3 kg wt (4) 20/9 kg wt

Discussion

424.	The boolean expression for the output 'F' of the logic circuit shown in the figure below is
Answer» The boolean expression for the output 'F' of the logic circuit shown in the figure below is

Discussion

425.	For the circuit shown in figure, the current supplied by battery will be
Answer» For the circuit shown in figure, the current supplied by battery will be

Discussion

426.	An equilateral prism deviates a ray through 23∘ for two angles of incidence differing by 23∘. Find μ of the prism?
Answer» An equilateral prism deviates a ray through $23^{\circ}$ for two angles of incidence differing by $23^{\circ}$ . Find $μ$ of the prism?

Discussion

427.	List down the causes and consequences of deforestation?
Answer» List down the causes and consequences of deforestation?

Discussion

428.	If 4×10−3 J of work is done in moving a particle carrying a charge of 16×10−6 C from infinity to a point. What will be the potential at that point?
Answer» If $4 \times 10^{- 3} J$ of work is done in moving a particle carrying a charge of $16 \times 10^{- 6} C$ from infinity to a point. What will be the potential at that point?

Discussion

429.

Match the column I with column II. Column I Column II a. Magnetic field inside a long straight solenoid is p. not constant b. Magnetic field inside a toroidal solenoid is q. zero c. Magnetic field inside a conducting hollow pipe having current parallel to its axis is r. constant d. Magnetic field due to current carrying wire on its surface is s. maximum

Answer»

Match the column $I$ with column $I I$ .

Column $I$	Column $I I$
$a .$ Magnetic field inside a long straight solenoid is	$p .$ not constant
$b .$ Magnetic field inside a toroidal solenoid is	$q .$ zero
$c .$ Magnetic field inside a conducting hollow pipe having current parallel to its axis is	$r .$ constant
$d .$ Magnetic field due to current carrying wire on its surface is	$s .$ maximum

Discussion

430.	If a wire of 10 ohms is stretched to double its length keeping it's volume constant then what will be the new resistance?
Answer» If a wire of 10 ohms is stretched to double its length keeping it's volume constant then what will be the new resistance?

Discussion

431.	State two advantages and two limitations of producing electricity from solar energy.
Answer» State two advantages and two limitations of producing electricity from solar energy.

Discussion

432.	The work done in moving a unit charge across two points in an electric circuit is a measure of: (a) current (b) potential difference (c) resistance (d) power
Answer» The work done in moving a unit charge across two points in an electric circuit is a measure of: (a) current (b) potential difference (c) resistance (d) power

Discussion

433.	The current flowing through a conductor is directly proportional to .................... between the ends of the conductor, provided the temperature and the state of matter of the conductor remain unchanged. __
Answer» The current flowing through a conductor is directly proportional to .................... between the ends of the conductor, provided the temperature and the state of matter of the conductor remain unchanged. __

Discussion

434.	The voltage of power generated at the generating stations is first stepped up before its transmission. Give reason.
Answer» The voltage of power generated at the generating stations is first stepped up before its transmission. Give reason.

434.

The voltage of power generated at the generating stations is first stepped up before its transmission. Give reason.

Answer»

The voltage of power generated at the generating stations is first stepped up before its transmission. Give reason.

Discussion

435.	What is the full form of MRI?
Answer» What is the full form of MRI?

Discussion

436.	A particle of mass m and charge q is released from origin in a region occupied by electric field E directed along x-axis and magnetic field directed along negative x-axis, speed of particle at position x is
Answer» A particle of mass m and charge q is released from origin in a region occupied by electric field E directed along x-axis and magnetic field directed along negative x-axis, speed of particle at position x is

Discussion

437.	35.Two Cu wires have diameter in the ratio 2:1 and tension in the ratio of 1:2 .the ratio of velocities of longitudinal wave in them is ??
Answer» 35.Two Cu wires have diameter in the ratio 2:1 and tension in the ratio of 1:2 .the ratio of velocities of longitudinal wave in them is ??

Discussion

438.	Which one of the following would raise thetemperature of 20 g of water at 300C most when mixed with? (Specificheat of water is 1 cal/g 0 C)
Answer» Which one of the following would raise the temperature of 20 g of water at 30⁰C most when mixed with? (Specific heat of water is 1 cal/g ⁰ C)

Discussion

439.	Mass of a body is 50g and it is subjected to a force of 0.01 N. Calculate the acceleration of the body in SI units and CGS units.
Answer» Mass of a body is 50g and it is subjected to a force of 0.01 N. Calculate the acceleration of the body in SI units and CGS units.

Discussion

440.	(a) Find the expression for the resistors connected in series and parallel.(b) Find the expression for resistivity of a material.
Answer» (a) Find the expression for the resistors connected in series and parallel. (b) Find the expression for resistivity of a material.

440.

(a) Find the expression for the resistors connected in series and parallel.(b) Find the expression for resistivity of a material.

Answer»

(a) Find the expression for the resistors connected in series and parallel.

(b) Find the expression for resistivity of a material.

Discussion

441.	A student performs an experiment with glass slab to trace the path of a ray of light entering from air into glass slab and emerging into air again. On looking carefully at the trace obtained on paper, he will observe that the emergent ray and the incident ray:(1) are converging (coming closer to each other)(2) are diverging (moving away from each other)(3) are perpendicular (at right angles to each other)(4) are parallel (at equidistant from each other)
Answer» A student performs an experiment with glass slab to trace the path of a ray of light entering from air into glass slab and emerging into air again. On looking carefully at the trace obtained on paper, he will observe that the emergent ray and the incident ray: (1) are converging (coming closer to each other) (2) are diverging (moving away from each other) (3) are perpendicular (at right angles to each other) (4) are parallel (at equidistant from each other)

Discussion

442.	a current of 8 A flows in a metallic conductor of cross section 1 cm^2 and length 10 km. Free electron density of copper is 5*10^28 /m^3. the time taken by the electron to travel from one end of the conductor to the other is a-10^8 s b-10^9 s c-10^7 s d-10^5 s
Answer» a current of 8 A flows in a metallic conductor of cross section 1 cm^2 and length 10 km. Free electron density of copper is 5*10^28 /m^3. the time taken by the electron to travel from one end of the conductor to the other is a-10^8 s b-10^9 s c-10^7 s d-10^5 s

Discussion

443.	Is Ozone paramagnetic or diamagnetic?
Answer» Is Ozone paramagnetic or diamagnetic?

Discussion

444.	Why is the actual position of star different from the apparent position?
Answer» Why is the actual position of star different from the apparent position?

Discussion

445.	A prism of angle A=1∘ has a refractive index μ=1.5. A good estimate for minimum angle of deviation (in degrees) is close to N10. Value of N is
Answer» A prism of angle $A = 1^{\circ}$ has a refractive index $μ = 1.5$ . A good estimate for minimum angle of deviation (in degrees) is close to $\frac{N}{10}$ . Value of $N$ is

Discussion

446.	Three resistances each of 4 Ohm are connected in the form of an equilateral triangle. The effective resistance between any two corners is:
Answer» Three resistances each of 4 Ohm are connected in the form of an equilateral triangle. The effective resistance between any two corners is:

Discussion

447.	Why biodegradable and non-biodegradable wastes should be discarded in two separate dust bins?
Answer» Why biodegradable and non-biodegradable wastes should be discarded in two separate dust bins?

Discussion

448.	A satellite of mass m is in the orbit round the earth at a distance of 2.5 R above its surface .if gravitational field strength at surface of earth is g calculate the centripetal force acting on the satellite .
Answer» A satellite of mass m is in the orbit round the earth at a distance of 2.5 R above its surface .if gravitational field strength at surface of earth is g calculate the centripetal force acting on the satellite .

Discussion

449.	Here is another poem on mirror. The narrator calls the mirror a 'fibber'. How is this poem different from the poem by Sylvia Plath? Have a class discussion on the comparison in terms of the theme, the tone and the language used.
Answer» Here is another poem on mirror. The narrator calls the mirror a 'fibber'. How is this poem different from the poem by Sylvia Plath? Have a class discussion on the comparison in terms of the theme, the tone and the language used.

Discussion

450.	A string of length L is fixed at one end and carries a mass M at the other end. The string makes 2π revolutions per second around the vertical axis through the fixed end as shown in the figure, then tension in the string is
Answer» A string of length $L$ is fixed at one end and carries a mass $M$ at the other end. The string makes $\frac{2}{π}$ revolutions per second around the vertical axis through the fixed end as shown in the figure, then tension in the string is

Discussion

Explore topic-wise InterviewSolutions in .

A block and tackle system has 5 pulleys. If an effort of 1000 N is needed in the downward direction to raise a load of 4500 N, calculate the efficiency(%) of the system.90

Which lens has more power : a thick lens or a thin lens ?

How magnetic field line are responsible for attraction and repulsion between two magnets and why??

___ is the linear distance between the pole and principal axis.

If an object is placed at a distance of 30 cm and the image is formed at a distance of 10 cm on the same side of the lens, then find the focal length of the lens used.

What is a prism? With the help of a diagram of a principal section of a prism, indicate its refracting surfaces, refracting angle and base.

Why does the sun appear reddish early in the morning

Who first discovered the relationship between electricity and magnetism?

A truck weighing 1000 kgf changes its speed from 36 km per hour in 2 minutes. Calculate: 1) The work done by the engine and its power

If the magnification produced by the lens is -0.5,the correct statement is:

A piece of wire of resistance 4 ohm is bent through 180° at its mid point and the two halves are twisted together, then find the resistance.

According to the "New Cartesian Sign Convention" for mirrors, what sign has been given to the focal length of : (i) a concave mirror ? (ii) a convex mirror ?

ntA short solenoid of length 4 cm, radius 2 cm and 100 turns is placed inside and on the axis of a long solenoid of length 80 cm and 1500 turns. A current of 3 A flows through the short solenoid. The mutual inductance of two solenoid isn

Characteristic property of light responsible for the blue colour of the sky is

What are the ammeter (A) and voltmeter (V) readings in the circuit?

how light travel in space with speed of 3×10^8m/s ?

Find the angular magnification in this case. (image at infinity)

Question 14An observer 1.5 m tall is 20.5 m away from a tower 22 m high. Determine the angle of elevation of the top of the tower from the eye of the observer.

a wire of one metre under a certain initial tension emits a sound of fundamental frequency 256 Hz when the tension is increased by 1 kg wt the frequency of the fundamental node increases to 320 Hz. The initial tension is(1) 3/4 kg wt(2)16/9 kg wt () 4/3 kg wt (4) 20/9 kg wt

The boolean expression for the output 'F' of the logic circuit shown in the figure below is

For the circuit shown in figure, the current supplied by battery will be

An equilateral prism deviates a ray through 23∘ for two angles of incidence differing by 23∘. Find μ of the prism?

List down the causes and consequences of deforestation?

If 4×10−3 J of work is done in moving a particle carrying a charge of 16×10−6 C from infinity to a point. What will be the potential at that point?

If a wire of 10 ohms is stretched to double its length keeping it's volume constant then what will be the new resistance?

State two advantages and two limitations of producing electricity from solar energy.

The work done in moving a unit charge across two points in an electric circuit is a measure of: (a) current (b) potential difference (c) resistance (d) power

The current flowing through a conductor is directly proportional to .................... between the ends of the conductor, provided the temperature and the state of matter of the conductor remain unchanged. __

The voltage of power generated at the generating stations is first stepped up before its transmission. Give reason.

What is the full form of MRI?

A particle of mass m and charge q is released from origin in a region occupied by electric field E directed along x-axis and magnetic field directed along negative x-axis, speed of particle at position x is

35.Two Cu wires have diameter in the ratio 2:1 and tension in the ratio of 1:2 .the ratio of velocities of longitudinal wave in them is ??

Which one of the following would raise thetemperature of 20 g of water at 300C most when mixed with? (Specificheat of water is 1 cal/g 0 C)

Mass of a body is 50g and it is subjected to a force of 0.01 N. Calculate the acceleration of the body in SI units and CGS units.

(a) Find the expression for the resistors connected in series and parallel.(b) Find the expression for resistivity of a material.

a current of 8 A flows in a metallic conductor of cross section 1 cm^2 and length 10 km. Free electron density of copper is 5*10^28 /m^3. the time taken by the electron to travel from one end of the conductor to the other is a-10^8 s b-10^9 s c-10^7 s d-10^5 s

Is Ozone paramagnetic or diamagnetic?

Why is the actual position of star different from the apparent position?

A prism of angle A=1∘ has a refractive index μ=1.5. A good estimate for minimum angle of deviation (in degrees) is close to N10. Value of N is

Three resistances each of 4 Ohm are connected in the form of an equilateral triangle. The effective resistance between any two corners is:

Why biodegradable and non-biodegradable wastes should be discarded in two separate dust bins?

A satellite of mass m is in the orbit round the earth at a distance of 2.5 R above its surface .if gravitational field strength at surface of earth is g calculate the centripetal force acting on the satellite .

Here is another poem on mirror. The narrator calls the mirror a 'fibber'. How is this poem different from the poem by Sylvia Plath? Have a class discussion on the comparison in terms of the theme, the tone and the language used.

A string of length L is fixed at one end and carries a mass M at the other end. The string makes 2π revolutions per second around the vertical axis through the fixed end as shown in the figure, then tension in the string is