13232 + Interview Questions in Physics Page 254 InterviewSolution

12651.	In a xerox machine, the black ink's toner particles are negatively charged. They strongly stick to the white A4 sheet paper and form letters and images. What charge should the A4 sheet possess for this process to happen?
Answer» In a xerox machine, the black ink's toner particles are negatively charged. They strongly stick to the white A4 sheet paper and form letters and images. What charge should the A4 sheet possess for this process to happen?

Discussion

12652.	An object of mass 40 kg is raised to a height of 5 m above the ground. What is its potential energy initially and at half way point? If the object is allowed to fall, find its kinetic energy when it is half-way down.
Answer» An object of mass $40 k g$ is raised to a height of $5 m$ above the ground. What is its potential energy initially and at half way point? If the object is allowed to fall, find its kinetic energy when it is half-way down.

Discussion

12653.	Which one is correct if a bullet is fired from a rifle?
Answer» Which one is correct if a bullet is fired from a rifle?

Discussion

12654.	In a sonar, ultrasonic waves are sent into the sea water and the reflected waves from a sunken ship are received after 2.0 s. If the velocity of waves in sea water is 1450 ms, find the depth of sunken ship.
Answer» In a sonar, ultrasonic waves are sent into the sea water and the reflected waves from a sunken ship are received after 2.0 s. If the velocity of waves in sea water is 1450 $\frac{m}{s}$ , find the depth of sunken ship.

Discussion

12655.	Which of the following represents electrical power in a circuit?
Answer» Which of the following represents electrical power in a circuit?

Discussion

12656.	In addition to speed, what else should we know to predict the position of a moving body?
Answer» In addition to speed, what else should we know to predict the position of a moving body?

Discussion

12657.	A cyclist Travels a distance of 4 km from P to Q and then moves a distance of 3 km at right angles to PQ. Find the resultant displacement graphically
Answer» A cyclist Travels a distance of 4 km from P to Q and then moves a distance of 3 km at right angles to PQ. Find the resultant displacement graphically

Discussion

12658.	In a map, a distance of 10 km on land is equal to 110 cm. If two places are 512 cm apart on the map, then what is the actual distance between them?
Answer» In a map, a distance of 10 km on land is equal to $\frac{1}{10} c m$ . If two places are $5 \frac{1}{2} c m$ apart on the map, then what is the actual distance between them?

Discussion

12659.	A sound wave has different speeds in different mediums because:
Answer» A sound wave has different speeds in different mediums because:

Discussion

12660.	Which of the following elements are used in the manufacturing of solar cells?
Answer» Which of the following elements are used in the manufacturing of solar cells?

Discussion

12661.	An unbalanced force acts in the direction of motion of a body. Then the body:
Answer» An unbalanced force acts in the direction of motion of a body. Then the body:

Discussion

12662.	If F is the force between two bodies of masses m1 and m2 at certain separation, then what is the force between √5 m1 and √3 m2 at same separation?
Answer» If F is the force between two bodies of masses $m_{1}$ and $m_{2}$ at certain separation, then what is the force between $\sqrt{5} m_{1}$ and $\sqrt{3} m_{2}$ at same separation?

Discussion

12663.	When C burns in excess air, it gives a blue coloured flame whereas when same C burns in limited air, colour of flame changes. Give reason.
Answer» When C burns in excess air, it gives a blue coloured flame whereas when same C burns in limited air, colour of flame changes. Give reason.

Discussion

12664.	Why bird fly in V shape.
Answer» Why bird fly in V shape.

Discussion

12665.	Why gamma rays are ionising if they have neutral charge?
Answer» Why gamma rays are ionising if they have neutral charge?

Discussion

12666.	The distance between Delhi and Agra is 200km .A train travels the first 100km at a speed of 50km/h .How fast must the train travel the next 100km ,so as to average 70km/h for the whole journey?
Answer» The distance between Delhi and Agra is 200km .A train travels the first 100km at a speed of 50km/h .How fast must the train travel the next 100km ,so as to average 70km/h for the whole journey?

Discussion

12667.	Wooden planks are placed between railway tracks.
Answer» Wooden planks are placed between railway tracks.

Discussion

12668.	In the given figure, a mirror is arranged at an angle 30∘ to the square shaped wooden board as shown. Find the angle made by the comb with its reflected shadow. [5 MARKS]
Answer» In the given figure, a mirror is arranged at an angle $30^{\circ}$ to the square shaped wooden board as shown. Find the angle made by the comb with its reflected shadow. [5 MARKS]

12668.

In the given figure, a mirror is arranged at an angle 30∘ to the square shaped wooden board as shown. Find the angle made by the comb with its reflected shadow. [5 MARKS]

Answer»

In the given figure, a mirror is arranged at an angle $30^{\circ}$ to the square shaped wooden board as shown. Find the angle made by the comb with its reflected shadow. [5 MARKS]

Discussion

12669.	Calculate the pressure at a depth of 50 m below the surface of the sea. The density of sea water is 1024 kg/m3.
Answer» Calculate the pressure at a depth of 50 $m$ below the surface of the sea. The density of sea water is 1024 $\frac{k g}{m^{3}}$ .

Discussion

12670.	If AB is the object and CD is the image formed. If AP is the object distance and CP is the image distance from the mirror. Then choose the correct sign convention? 1. height of image = + ve 2. height of image = – ve 3. height of object = + ve 4. height of object = – ve 5. AP = + ve 6. AP = – ve 7. PC = + ve 8. PC = – ve.
Answer» If AB is the object and CD is the image formed. If AP is the object distance and CP is the image distance from the mirror. Then choose the correct sign convention? 1. height of image = + ve 2. height of image = – ve 3. height of object = + ve 4. height of object = – ve 5. AP = + ve 6. AP = – ve 7. PC = + ve 8. PC = – ve.

12670.

If AB is the object and CD is the image formed. If AP is the object distance and CP is the image distance from the mirror. Then choose the correct sign convention? 1. height of image = + ve 2. height of image = – ve 3. height of object = + ve 4. height of object = – ve 5. AP = + ve 6. AP = – ve 7. PC = + ve 8. PC = – ve.

Answer»

If AB is the object and CD is the image formed. If AP is the object distance and CP is the image distance from the mirror. Then choose the correct sign convention?

1. height of image = + ve 2. height of image = – ve

3. height of object = + ve 4. height of object = – ve

5. AP = + ve 6. AP = – ve

7. PC = + ve 8. PC = – ve.

Discussion

12671.	How do sensors work
Answer» How do sensors work

Discussion

12672.	In a simple barometer, some air is trapped in the space above the mercury column. Let H be the height of the mercury column initially. When the tube is further pushed into the vessel, what happens to the height of the mercury column ‘H’ in the tube?
Answer» In a simple barometer, some air is trapped in the space above the mercury column. Let H be the height of the mercury column initially. When the tube is further pushed into the vessel, what happens to the height of the mercury column ‘H’ in the tube?

12672.

In a simple barometer, some air is trapped in the space above the mercury column. Let H be the height of the mercury column initially. When the tube is further pushed into the vessel, what happens to the height of the mercury column ‘H’ in the tube?

Answer»

In a simple barometer, some air is trapped in the space above the mercury column. Let H be the height of the mercury column initially. When the tube is further pushed into the vessel, what happens to the height of the mercury column ‘H’ in the tube?

Discussion

12673.	M^2+ contains 10 electrons and 10 neutrons (i) What is atomic number and mass number of the element M (ii) Is it possible in an atom to have 13 protons and 13 neutrons . (iii) Why helium gas is inert
Answer» ^{M^2+ contains 10 electrons and 10 neutrons (i) What is atomic number and mass number of the element M (ii) Is it possible in an atom to have 13 protons and 13 neutrons . (iii) Why helium gas is inert}

Discussion

12674.	It was a rainy day in Bangalore. Rohit was sitting besides the window when he saw a lightning. He started his stop watch. He found that after 22 seconds of lightning its roaring was heard. Calculate the height of the clouds which caused this lightning. Given, speed of light = 3×108 ms−1 and speed of sound = 340 ms−1.
Answer» It was a rainy day in Bangalore. Rohit was sitting besides the window when he saw a lightning. He started his stop watch. He found that after $22$ seconds of lightning its roaring was heard. Calculate the height of the clouds which caused this lightning. Given, speed of light = $3 \times 10^{8}$ $m s^{- 1}$ and speed of sound = $340 m s^{- 1}$ .

Discussion

12675.	Newton s first law or law of innertia
Answer» Newton s first law or law of innertia

Discussion

12676.	A loaded spring gun of mass M fires a shot of mass m with a velocity v at an angle of elevation θ. The gun is initially at rest on a horizontal frictionless surface. After firing, the centre of mass of the gun-shot system
Answer» A loaded spring gun of mass M fires a shot of mass m with a velocity v at an angle of elevation $θ$ . The gun is initially at rest on a horizontal frictionless surface. After firing, the centre of mass of the gun-shot system

Discussion

12677.	A lecture theatre of a college is 40 feet wide and has a door at a corner teacher entrance at 12 noon through the door and next 10 rounds along the 40 feet wall back and forth during the period and finally leaves the classroom at 12:50 p.m. to the same door compute his average speed and average velocity
Answer» A lecture theatre of a college is 40 feet wide and has a door at a corner teacher entrance at 12 noon through the door and next 10 rounds along the 40 feet wall back and forth during the period and finally leaves the classroom at 12:50 p.m. to the same door compute his average speed and average velocity

Discussion

12678.	The area of trapezium OABC in the velocity-time graph gives the:
Answer» The area of trapezium OABC in the velocity-time graph gives the:

12678.

The area of trapezium OABC in the velocity-time graph gives the:

Answer»

The area of trapezium OABC in the velocity-time graph gives the:

Discussion

12679.	Find the refractive index of the core of an optical fiber if the critical angle is 60∘ and the refractive index of the cladding is √3?
Answer» Find the refractive index of the core of an optical fiber if the critical angle is $60^{\circ}$ and the refractive index of the cladding is $\sqrt{3}$ ?

Discussion

12680.	The device used to measure Relative Density is called
Answer» The device used to measure Relative Density is called

Discussion

12681.	In a uniform magnetic field, the field lines are : (a) curved (b) parallel and equidistant straight lines (c) parallel, but non-equispaced straight lines (d) nothing can be said.
Answer» In a uniform magnetic field, the field lines are : (a) curved (b) parallel and equidistant straight lines (c) parallel, but non-equispaced straight lines (d) nothing can be said.

12681.

In a uniform magnetic field, the field lines are : (a) curved (b) parallel and equidistant straight lines (c) parallel, but non-equispaced straight lines (d) nothing can be said.

Answer»

In a uniform magnetic field, the field lines are :

(a) curved

(b) parallel and equidistant straight lines

(c) parallel, but non-equispaced straight lines

(d) nothing can be said.

Discussion

12682.	Question 27 Define watt. Express kilowatt in terms of joule per second. A 150 kg car engine develops 500 W for each kg. What force does it exert in moving the car at a speed of 20 ms−1?
Answer» Question 27 Define watt. Express kilowatt in terms of joule per second. A 150 kg car engine develops 500 W for each kg. What force does it exert in moving the car at a speed of $20 m s^{- 1}$ ?

Discussion

12683.	(a) Define the following terms : (a) Echolocation (b) Echocardiography, and (c) Ultrasonography. (b) Name an animal which navigates and finds food by echolocation. (c) Which of the two produces ultrasonic waves: porpoise or whale?
Answer» (a) Define the following terms : (a) Echolocation (b) Echocardiography, and (c) Ultrasonography. (b) Name an animal which navigates and finds food by echolocation. (c) Which of the two produces ultrasonic waves: porpoise or whale?

12683.

(a) Define the following terms : (a) Echolocation (b) Echocardiography, and (c) Ultrasonography. (b) Name an animal which navigates and finds food by echolocation. (c) Which of the two produces ultrasonic waves: porpoise or whale?

Answer»

(a) Define the following terms : (a) Echolocation (b) Echocardiography, and (c) Ultrasonography.

(b) Name an animal which navigates and finds food by echolocation.

(c) Which of the two produces ultrasonic waves: porpoise or whale?

Discussion

12684.	The factor by which the kinetic energy of a moving body changes when its speed is reduced to half
Answer» The factor by which the kinetic energy of a moving body changes when its speed is reduced to half

Discussion

12685.	A logwood of mass 120 Kg floats in water. The weight that can be put on the raft to make it just sink should be (density of wood=600Kg/m3)
Answer» A logwood of mass 120 Kg floats in water. The weight that can be put on the raft to make it just sink should be (density of wood=600Kg/m³)

Discussion

12686.	What do you mean by anomalous expansion of water?
Answer» What do you mean by anomalous expansion of water?

Discussion

12687.	Question 2 A farmer moves along the boundary of a square field of side 10 m in 40 s. What will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds?
Answer» Question 2 A farmer moves along the boundary of a square field of side 10 m in 40 s. What will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds?

Discussion

12688.	The centre of mass is a point
Answer» The centre of mass is a point

Discussion

12689.	What is mole fraction represented by?
Answer» What is mole fraction represented by?

Discussion

12690.	Let’s say a thief is running on a train with 12 km/h. The police car is moving with 80 km/h. If speed of the train is 60 km/h. What is the speed of thief w.r.t police car?
Answer» Let’s say a thief is running on a train with 12 km/h. The police car is moving with 80 km/h. If speed of the train is 60 km/h. What is the speed of thief w.r.t police car?

Discussion

12691.	A truck has a mass of 8000 kgs, a car has a mass of 1000 kgs and a bike has a mass of 100 kgs.All of them are moving with the same speed on a road. Then the kinetic energy will be more for the _____
Answer» A truck has a mass of 8000 kgs, a car has a mass of 1000 kgs and a bike has a mass of 100 kgs.All of them are moving with the same speed on a road. Then the kinetic energy will be more for the _____

Discussion

12692.	The value of gravitational constant, G is
Answer» The value of gravitational constant, $G$ is

Discussion

12693.	The weight of a solid is 80g in air and 50g in a liquid of relative density 1.5. Calculate the relative density of the solid.
Answer» The weight of a solid is 80g in air and 50g in a liquid of relative density 1.5. Calculate the relative density of the solid.

Discussion

12694.	Find out the pressure value at A point which is at a depth of 2 m from the water surface. Density of water (ρ) is =1000 kg/m2. (Atmospheric pressure P0 =105 Pa & g=10 m/s2 )
Answer» Find out the pressure value at A point which is at a depth of 2 $m$ from the water surface. Density of water ( $ρ$ ) is $= 1000 k g / m^{2}$ . (Atmospheric pressure $P_{0}$ $= 10^{5} P a$ & $g = 10 m / s^{2}$ )

Discussion

12695.	A ray of light is incident on the plane mirror at a angle as shown in the figure, what is the angle made by the reflected ray to the normal?
Answer» A ray of light is incident on the plane mirror at a angle as shown in the figure, what is the angle made by the reflected ray to the normal?

Discussion

12696.	The gravitational force between any two bodies is
Answer» The gravitational force between any two bodies is

Discussion

12697.	State four ways for the judicious use of energy.
Answer» State four ways for the judicious use of energy.

Discussion

12698.	The weight of an object is
Answer» The weight of an object is

Discussion

12699.	The amount of inertia that an object possesses is:
Answer» The amount of inertia that an object possesses is:

Discussion

12700.	A feather is dropped on the moon from a height of 10 m. The acceleration due to gravity on the moon is 1.67 ms−2. Determine the time taken by the feather to fall on the surface of the moon.
Answer» A feather is dropped on the moon from a height of 10 m. The acceleration due to gravity on the moon is $1.67 m s^{- 2}$ . Determine the time taken by the feather to fall on the surface of the moon.

Discussion

Explore topic-wise InterviewSolutions in .

In a xerox machine, the black ink's toner particles are negatively charged. They strongly stick to the white A4 sheet paper and form letters and images. What charge should the A4 sheet possess for this process to happen?

An object of mass 40 kg is raised to a height of 5 m above the ground. What is its potential energy initially and at half way point? If the object is allowed to fall, find its kinetic energy when it is half-way down.

Which one is correct if a bullet is fired from a rifle?

In a sonar, ultrasonic waves are sent into the sea water and the reflected waves from a sunken ship are received after 2.0 s. If the velocity of waves in sea water is 1450 ms, find the depth of sunken ship.

Which of the following represents electrical power in a circuit?

In addition to speed, what else should we know to predict the position of a moving body?

A cyclist Travels a distance of 4 km from P to Q and then moves a distance of 3 km at right angles to PQ. Find the resultant displacement graphically

In a map, a distance of 10 km on land is equal to 110 cm. If two places are 512 cm apart on the map, then what is the actual distance between them?

A sound wave has different speeds in different mediums because:

Which of the following elements are used in the manufacturing of solar cells?

An unbalanced force acts in the direction of motion of a body. Then the body:

If F is the force between two bodies of masses m1 and m2 at certain separation, then what is the force between √5 m1 and √3 m2 at same separation?

When C burns in excess air, it gives a blue coloured flame whereas when same C burns in limited air, colour of flame changes. Give reason.

Why bird fly in V shape.

Why gamma rays are ionising if they have neutral charge?

The distance between Delhi and Agra is 200km .A train travels the first 100km at a speed of 50km/h .How fast must the train travel the next 100km ,so as to average 70km/h for the whole journey?

Wooden planks are placed between railway tracks.

In the given figure, a mirror is arranged at an angle 30∘ to the square shaped wooden board as shown. Find the angle made by the comb with its reflected shadow. [5 MARKS]

Calculate the pressure at a depth of 50 m below the surface of the sea. The density of sea water is 1024 kg/m3.

How do sensors work

In a simple barometer, some air is trapped in the space above the mercury column. Let H be the height of the mercury column initially. When the tube is further pushed into the vessel, what happens to the height of the mercury column ‘H’ in the tube?

​​​​​​M^2+ contains 10 electrons and 10 neutrons (i) What is atomic number and mass number of the element M (ii) Is it possible in an atom to have 13 protons and 13 neutrons . (iii) Why helium gas is inert

Newton s first law or law of innertia

A loaded spring gun of mass M fires a shot of mass m with a velocity v at an angle of elevation θ. The gun is initially at rest on a horizontal frictionless surface. After firing, the centre of mass of the gun-shot system

The area of trapezium OABC in the velocity-time graph gives the:

Find the refractive index of the core of an optical fiber if the critical angle is 60∘ and the refractive index of the cladding is √3?

The device used to measure Relative Density is called

In a uniform magnetic field, the field lines are : (a) curved (b) parallel and equidistant straight lines (c) parallel, but non-equispaced straight lines (d) nothing can be said.

Question 27 Define watt. Express kilowatt in terms of joule per second. A 150 kg car engine develops 500 W for each kg. What force does it exert in moving the car at a speed of 20 ms−1?

(a) Define the following terms : (a) Echolocation (b) Echocardiography, and (c) Ultrasonography. (b) Name an animal which navigates and finds food by echolocation. (c) Which of the two produces ultrasonic waves: porpoise or whale?

The factor by which the kinetic energy of a moving body changes when its speed is reduced to half

A logwood of mass 120 Kg floats in water. The weight that can be put on the raft to make it just sink should be (density of wood=600Kg/m3)

What do you mean by anomalous expansion of water?

Question 2 A farmer moves along the boundary of a square field of side 10 m in 40 s. What will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds?

The centre of mass is a point

What is mole fraction represented by?

Let’s say a thief is running on a train with 12 km/h. The police car is moving with 80 km/h. If speed of the train is 60 km/h. What is the speed of thief w.r.t police car?

A truck has a mass of 8000 kgs, a car has a mass of 1000 kgs and a bike has a mass of 100 kgs.All of them are moving with the same speed on a road. Then the kinetic energy will be more for the _____

The value of gravitational constant, G is

The weight of a solid is 80g in air and 50g in a liquid of relative density 1.5. Calculate the relative density of the solid.

Find out the pressure value at A point which is at a depth of 2 m from the water surface. Density of water (ρ) is =1000 kg/m2. (Atmospheric pressure P0 =105 Pa &amp; g=10 m/s2 )

A ray of light is incident on the plane mirror at a angle as shown in the figure, what is the angle made by the reflected ray to the normal?

The gravitational force between any two bodies is

State four ways for the judicious use of energy.

The weight of an object is

The amount of inertia that an object possesses is:

A feather is dropped on the moon from a height of 10 m. The acceleration due to gravity on the moon is 1.67 ms−2​. Determine the time taken by the feather to fall on the surface of the moon.

M^2+ contains 10 electrons and 10 neutrons (i) What is atomic number and mass number of the element M (ii) Is it possible in an atom to have 13 protons and 13 neutrons . (iii) Why helium gas is inert

Find out the pressure value at A point which is at a depth of 2 m from the water surface. Density of water (ρ) is =1000 kg/m2. (Atmospheric pressure P0 =105 Pa & g=10 m/s2 )

A feather is dropped on the moon from a height of 10 m. The acceleration due to gravity on the moon is 1.67 ms−2. Determine the time taken by the feather to fall on the surface of the moon.