6277 + Interview Questions in Physics Page 15 InterviewSolution

701.	What do you mean by conservation of mechanical energy? State the condition when it holds
Answer» What do you mean by conservation of mechanical energy? State the condition when it holds

Discussion

702.	Which instrument do the designers of wallpapers and artists use to get ideas for new patterns? [1 MARK]
Answer» Which instrument do the designers of wallpapers and artists use to get ideas for new patterns? [1 MARK]

Discussion

703.	A piece of chalk is going around a fixed axis 00' as shown in figure such that it takes equal amount of time in completing each revolution about 00' as well as about its own Axis AB. (which passes through its centre and is parallel to 00') What can be said about this type of motion of this chalk piece?
Answer» A piece of chalk is going around a fixed axis 00' as shown in figure such that it takes equal amount of time in completing each revolution about 00' as well as about its own Axis AB. (which passes through its centre and is parallel to 00') What can be said about this type of motion of this chalk piece?

703.

A piece of chalk is going around a fixed axis 00' as shown in figure such that it takes equal amount of time in completing each revolution about 00' as well as about its own Axis AB. (which passes through its centre and is parallel to 00') What can be said about this type of motion of this chalk piece?

Answer»

A piece of chalk is going around a fixed axis 00' as shown in figure such that it takes equal amount of time in completing each revolution about 00' as well as about its own Axis AB. (which passes through its centre and is parallel to 00') What can be said about this type of motion of this chalk piece?

Discussion

704.	Pressure in a liquid increases with increase in ___.
Answer» Pressure in a liquid increases with increase in ___.

Discussion

705.	{ †ext { A man swims across a river with speed of } 5 km h ^ { - 1 } †ext { (in still water), while a boat goes upstream } } { †ext { with speed } 12 km h ^ { - 1 } †ext { (in still water). How fast and in which direction does the man appear to go } } { †ext { to the boatman? Given that the speed of flowing water is } 2 km h ^ { - 1 } †ext { . }
Answer» { †ext { A man swims across a river with speed of } 5 km h ^ { - 1 } †ext { (in still water), while a boat goes upstream } } { †ext { with speed } 12 km h ^ { - 1 } †ext { (in still water). How fast and in which direction does the man appear to go } } { †ext { to the boatman? Given that the speed of flowing water is } 2 km h ^ { - 1 } †ext { . }

Discussion

706.	A particle starts from the origin, goes along x-axis to the point (20m,0) and then returns along the same line to the point (20m,0). The distance and the displacement of the particle during the trip are a. 40m,0 b. 40m, 20m c. 40m, -20m d. 60m, -20m
Answer» A particle starts from the origin, goes along x-axis to the point (20m,0) and then returns along the same line to the point (20m,0). The distance and the displacement of the particle during the trip are a. 40m,0 b. 40m, 20m c. 40m, -20m d. 60m, -20m

Discussion

707.	What are the three types of motion?
Answer» What are the three types of motion?

Discussion

708.	Take a tin can with a lid and fill it half with water. Heat the can on a candle flame till the water boils. Let the water boil for a few minutes and immediately put the lid tightly on the can. Pour fresh water over the can. You'll see the shape of the tin box changes. This is due to:
Answer» Take a tin can with a lid and fill it half with water. Heat the can on a candle flame till the water boils. Let the water boil for a few minutes and immediately put the lid tightly on the can. Pour fresh water over the can. You'll see the shape of the tin box changes. This is due to:

Discussion

709.	Pick a good conductor of heat from the following:
Answer» Pick a good conductor of heat from the following:

Discussion

710.	Why kinetic energy is taken as zero when it reaches at infinity
Answer» Why kinetic energy is taken as zero when it reaches at infinity

Discussion

711.	92. A pendulum having a bob of mass m is hanging in a ship sailing along the equator from east to west. When the ship is stationary with respect to water the tension in the string is T . (a) Find the speed of the ship due to rotation of the earth about its axis . (B) Find the difference between T and the earths attraction on the Bob. (C) If the ship sails at speed V , what is the tension in the string ? Angular speed of earths rotation is omega (w) and radius of the earth is R.
Answer» 92. A pendulum having a bob of mass m is hanging in a ship sailing along the equator from east to west. When the ship is stationary with respect to water the tension in the string is T . (a) Find the speed of the ship due to rotation of the earth about its axis . (B) Find the difference between T and the earths attraction on the Bob. (C) If the ship sails at speed V , what is the tension in the string ? Angular speed of earths rotation is omega (w) and radius of the earth is R.

Discussion

712.	What are the causes of floods? How can we prevent it?
Answer» What are the causes of floods? How can we prevent it?

Discussion

713.	A ray of light is incident at 60∘, on glass-air interface. Then the light ray will ___. (Given: Incident ray lies in glass). Use : [μg = √2 , μa = 1]
Answer» A ray of light is incident at $60^{\circ}$ , on glass-air interface. Then the light ray will ___. (Given: Incident ray lies in glass). Use : [ $μ_{g}$ = $\sqrt{2}$ , $μ_{a}$ = 1]

Discussion

714.	A potentiometer wire is having a length of 10m and resistance 100 Omega.It is connected in series with a cell of emf 10V and an unknown external resistance R .A cell of emf 2V is balanced against a length of 4m of the potentiometer wire.The value of unknown resistance R is
Answer» A potentiometer wire is having a length of 10m and resistance 100 Omega.It is connected in series with a cell of emf 10V and an unknown external resistance R .A cell of emf 2V is balanced against a length of 4m of the potentiometer wire.The value of unknown resistance R is

Discussion

715.	A system X is neither in thermal equilibrium with Y nor with Z. The systems Y and Z__.
Answer» A system X is neither in thermal equilibrium with Y nor with Z. The systems Y and Z__.

Discussion

716.	Periodic motion is used in the working of
Answer» Periodic motion is used in the working of

Discussion

717.	what is kepelar's law of motio
Answer» what is kepelar's law of motio

Discussion

718.	In a new system of units the unit of mass is a kg the units of length and time are respectively b metre and c seconds. What is the magnitude of 6 watt of power in the system?
Answer» In a new system of units the unit of mass is a kg the units of length and time are respectively b metre and c seconds. What is the magnitude of 6 watt of power in the system?

Discussion

719.	a peraon 1.6 m tall is s†an ding at the centre betwwen two walls three metre high what is the minimum size of a plane mirror fixed on wall in feont of him if he is to see the full height of wall behind him
Answer» a peraon 1.6 m tall is s†an ding at the centre betwwen two walls three metre high what is the minimum size of a plane mirror fixed on wall in feont of him if he is to see the full height of wall behind him

Discussion

720.	The dentist uses a _______ mirror.
Answer» The dentist uses a _______ mirror.

Discussion

721.	Fast wind can lift off a roof from a house. Does this happen because of increased pressure or reduced pressure?
Answer» Fast wind can lift off a roof from a house. Does this happen because of increased pressure or reduced pressure?

Discussion

722.	Outer surface area of a hollow iron sphere is 1256 cm2. If the thickness of iron is 1 cm, find the volume of air inside the sphere. Take π=3.14
Answer» Outer surface area of a hollow iron sphere is $1256 c m^{2}$ . If the thickness of iron is $1 c m$ , find the volume of air inside the sphere. Take $π = 3.14$

Discussion

723.	• Choose the right word from the box below and fill in the blanks.pulled took blew felt wanted startedOne day the wind and the sun had a competition. They _________ to make a man take off his coat. First, the wind ________ hard. The man _________ his coat tightly round himself. Then the sun ________ shining hard. The man _________ hot and he ________ off his coat.
Answer» • Choose the right word from the box below and fill in the blanks. pulled took blew felt wanted started One day the wind and the sun had a competition. They _________ to make a man take off his coat. First, the wind ________ hard. The man _________ his coat tightly round himself. Then the sun ________ shining hard. The man _________ hot and he ________ off his coat.

Discussion

724.	5. A ray of light is incident on a plane mirroralong the direction given by vectorA-21-3j+4k. Find the unit vector alongreflected ray. Take normal to mirror along thedirection of vector B 3i-6j+
Answer» 5. A ray of light is incident on a plane mirroralong the direction given by vectorA-21-3j+4k. Find the unit vector alongreflected ray. Take normal to mirror along thedirection of vector B 3i-6j+

Discussion

725.	A fish moves in an aquarium, with the velocity of a 10m/s towards a plane mirror which is moving at a velocity of 2m/s away from the aquarium. The aquarium is moving towards the mirror at a velocity of 1m/s. Find the velocity of the image of the fish. Refractive index of waterin 3/4\| \| \|\\| \| \|\\| \| \|\ --mirror---{\| Fish----> \| \|\ 2m/s\| 10m/s \| \|\\| \| \|\ \|______________\| \|\ --aquarium---> 1m/sVelocity of image of the fish if refractive index of the water is 3/4
Answer» A fish moves in an aquarium, with the velocity of a 10m/s towards a plane mirror which is moving at a velocity of 2m/s away from the aquarium. The aquarium is moving towards the mirror at a velocity of 1m/s. Find the velocity of the image of the fish. Refractive index of waterin 3/4 \| \| \|\ \| \| \|\ \| \| \|\ --mirror---{ \| Fish----> \| \|\ 2m/s \| 10m/s \| \|\ \| \| \|\ \|______________\| \|\ --aquarium---> 1m/s Velocity of image of the fish if refractive index of the water is 3/4

Discussion

726.	Charge flowing through a resistor of resis†an ce R at any time t is given by Q=Q_0e^{-t/a} where a is a cons†an t. The rate of heat generation in resistor at t=0 is?
Answer» Charge flowing through a resistor of resis†an ce R at any time t is given by Q=Q_0e^{-t/a} where a is a cons†an t. The rate of heat generation in resistor at t=0 is?

Discussion

727.	air is cooled from 273c to 0c,the decrease in rms speed is about
Answer» air is cooled from 273c to 0c,the decrease in rms speed is about

Discussion

728.	Differentiate between plane mirror and spherical mirror?
Answer» Differentiate between plane mirror and spherical mirror?

Discussion

729.	An object is placed 60 cm in front of a convex mirror of focal length 30 cm. A plane mirror is now placed facing the object in between the object and the convex mirror such that it covers lower half of the convex mirror. What should be the distance of the plane mirror from the object so that there will be no parallax between the images formed by the two mirrors?
Answer» An object is placed $60 c m$ in front of a convex mirror of focal length $30 c m$ . A plane mirror is now placed facing the object in between the object and the convex mirror such that it covers lower half of the convex mirror. What should be the distance of the plane mirror from the object so that there will be no parallax between the images formed by the two mirrors?

Discussion

730.	Who invented the rotating magnetic field?
Answer» Who invented the rotating magnetic field?

Discussion

731.	Give three applications of convection of heat .
Answer» Give three applications of convection of heat .

Discussion

732.	Give reasons for the following : (a) No work is done if a man is pushing against a wall. (b) The hammer drives a nail into the wood only when it is lifted up and then struck. (c) A horse and a dog are running at the same speed. Which one of them has more kinetic energy than the other (d) A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work?
Answer» Give reasons for the following : (a) No work is done if a man is pushing against a wall. (b) The hammer drives a nail into the wood only when it is lifted up and then struck. (c) A horse and a dog are running at the same speed. Which one of them has more kinetic energy than the other (d) A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work?

732.

Give reasons for the following : (a) No work is done if a man is pushing against a wall. (b) The hammer drives a nail into the wood only when it is lifted up and then struck. (c) A horse and a dog are running at the same speed. Which one of them has more kinetic energy than the other (d) A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work?

Answer»

Give reasons for the following :

(a) No work is done if a man is pushing against a wall.

(b) The hammer drives a nail into the wood only when it is lifted up and then struck.

(c) A horse and a dog are running at the same speed. Which one of them has more kinetic energy than the other

(d) A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work?

Discussion

733.	Why does a compass have a lightweight magnet and a frictionless bearing?
Answer» Why does a compass have a lightweight magnet and a frictionless bearing?

Discussion

734.	65.Sphere of radius R and made of material of relative density 1.5 has a concentric cavity of radius r. it just floats when placed in a tank full of water. the value of R/r is
Answer» 65.Sphere of radius R and made of material of relative density 1.5 has a concentric cavity of radius r. it just floats when placed in a tank full of water. the value of R/r is

Discussion

735.	why only when the object is placed between the pole and focus is virtual and at any other place is real in a concave mirror?
Answer» why only when the object is placed between the pole and focus is virtual and at any other place is real in a concave mirror?

Discussion

736.	Question 6The change in seasons on the earth occurs because(a) the distance between the earth and the sun is not constant.(b) the axis of rotation of the earth is parallel to the plane of its orbit.(c) the axis of rotation of the earth is perpendicular to the plane of its orbit.(d) the axis of rotation of the earth is tilted with respect to the plane of its orbit.
Answer» Question 6 The change in seasons on the earth occurs because (a) the distance between the earth and the sun is not constant. (b) the axis of rotation of the earth is parallel to the plane of its orbit. (c) the axis of rotation of the earth is perpendicular to the plane of its orbit. (d) the axis of rotation of the earth is tilted with respect to the plane of its orbit.

Discussion

737.	What are the various forms of enegy conversion which take place when a ball is dropped from a height? Lets consider real scenarios with air drag and friction
Answer» What are the various forms of enegy conversion which take place when a ball is dropped from a height? Lets consider real scenarios with air drag and friction

Discussion

738.	In the month of June, on one day the maximum temperature in Delhi was recorded as 108.32 degree Fahrenheit.What is temperaure in degree celsius?
Answer» In the month of June, on one day the maximum temperature in Delhi was recorded as 108.32 degree Fahrenheit.What is temperaure in degree celsius?

Discussion

739.	Three ships A, B and C are in motion. The motion of A as seen by B is with speed v towards north east. The motion of B as seen by C is with speed v towards the north-west. Then as seen by A, C will be moving towards:1) north 2) south 3) east 4) west.
Answer» Three ships A, B and C are in motion. The motion of A as seen by B is with speed v towards north east. The motion of B as seen by C is with speed v towards the north-west. Then as seen by A, C will be moving towards: 1) north 2) south 3) east 4) west.

Discussion

740.	Who first discovered the magnetic effect of electricity?
Answer» Who first discovered the magnetic effect of electricity?

Discussion

741.	It was a rainy day in Bangalore. Rohit was sitting beside the window when he saw a lightning. He started his stopwatch. 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 = 3x108ms and Speed of sound = 340ms.
Answer» It was a rainy day in Bangalore. Rohit was sitting beside the window when he saw a lightning. He started his stopwatch. 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 = $3 x 10^{8} \frac{m}{s}$ and Speed of sound = $340 \frac{m}{s}$ .

Discussion

742.	134.find out the electic field at the centre of hemisphere with the charge sigma C/m2 on the sphere
Answer» 134.find out the electic field at the centre of hemisphere with the charge sigma C/m2 on the sphere

Discussion

743.	19. When force F and 3F are exerted on similar area, then the ratio of pressure will be ?
Answer» 19. When force F and 3F are exerted on similar area, then the ratio of pressure will be ?

Discussion

744.	If the angle of incidence is 60 degree for an incident ray on a surface, then what is the angle of reflection?
Answer» If the angle of incidence is 60 degree for an incident ray on a surface, then what is the angle of reflection?

Discussion

745.	A particle is moving from origin towards the north direction for 1km. Again in north-east direction for 1km and then towards west for 1km. Calculate the ratio of displacement to distance.
Answer» A particle is moving from origin towards the north direction for 1km. Again in north-east direction for 1km and then towards west for 1km. Calculate the ratio of displacement to distance.

Discussion

746.	A load of 10 kN is supported from a pulley which in turn is supported by a rope of cross-sectional area 103 mm2 and modulus of elasticity 103 N/mm2 as shown in the figure. Neglecting friction at the pulley, downward deflection of the load (in mm) is
Answer» A load of $10 kN$ is supported from a pulley which in turn is supported by a rope of cross-sectional area $10^{3} {mm}^{2}$ and modulus of elasticity $10^{3} {N/mm}^{2}$ as shown in the figure. Neglecting friction at the pulley, downward deflection of the load $(in mm)$ is

Discussion

747.	A football is placed in the path of light as shown below. If the light source is horizontally placed, what will be the shape of the shadow cast by it on the vertical screen?
Answer» A football is placed in the path of light as shown below. If the light source is horizontally placed, what will be the shape of the shadow cast by it on the vertical screen?

747.

A football is placed in the path of light as shown below. If the light source is horizontally placed, what will be the shape of the shadow cast by it on the vertical screen?

Answer»

A football is placed in the path of light as shown below. If the light source is horizontally placed, what will be the shape of the shadow cast by it on the vertical screen?

Discussion

748.	what is general formula for all the situations of doppler effect in 1)sound waves, 2) light waves
Answer» what is general formula for all the situations of doppler effect in 1)sound waves, 2) light waves

Discussion

749.	A torch requires 3 cells. Show the arrangement of the cells, with a diagram, inside the torch so that the bulb glows.
Answer» A torch requires 3 cells. Show the arrangement of the cells, with a diagram, inside the torch so that the bulb glows.

Discussion

750.	What is a potential energy
Answer» What is a potential energy

Discussion

Explore topic-wise InterviewSolutions in .

What do you mean by conservation of mechanical energy? State the condition when it holds

Which instrument do the designers of wallpapers and artists use to get ideas for new patterns? [1 MARK]

Pressure in a liquid increases with increase in ___.

A particle starts from the origin, goes along x-axis to the point (20m,0) and then returns along the same line to the point (20m,0). The distance and the displacement of the particle during the trip are a. 40m,0 b. 40m, 20m c. 40m, -20m d. 60m, -20m

What are the three types of motion?

Take a tin can with a lid and fill it half with water. Heat the can on a candle flame till the water boils. Let the water boil for a few minutes and immediately put the lid tightly on the can. Pour fresh water over the can. You'll see the shape of the tin box changes. This is due to:

Pick a good conductor of heat from the following:

Why kinetic energy is taken as zero when it reaches at infinity

What are the causes of floods? How can we prevent it?

A ray of light is incident at 60∘, on glass-air interface. Then the light ray will ___. (Given: Incident ray lies in glass). Use : [μg = √2 , μa = 1]

A potentiometer wire is having a length of 10m and resistance 100 Omega.It is connected in series with a cell of emf 10V and an unknown external resistance R .A cell of emf 2V is balanced against a length of 4m of the potentiometer wire.The value of unknown resistance R is

A system X is neither in thermal equilibrium with Y nor with Z. The systems Y and Z__.

Periodic motion is used in the working of

what is kepelar's law of motio

In a new system of units the unit of mass is a kg the units of length and time are respectively b metre and c seconds. What is the magnitude of 6 watt of power in the system?

a peraon 1.6 m tall is s†an ding at the centre betwwen two walls three metre high what is the minimum size of a plane mirror fixed on wall in feont of him if he is to see the full height of wall behind him

The dentist uses a _______ mirror.

Fast wind can lift off a roof from a house. Does this happen because of increased pressure or reduced pressure?

Outer surface area of a hollow iron sphere is 1256 cm2. If the thickness of iron is 1 cm, find the volume of air inside the sphere. Take π=3.14

5. A ray of light is incident on a plane mirroralong the direction given by vectorA-21-3j+4k. Find the unit vector alongreflected ray. Take normal to mirror along thedirection of vector B 3i-6j+

Charge flowing through a resistor of resis†an ce R at any time t is given by Q=Q_0e^{-t/a} where a is a cons†an t. The rate of heat generation in resistor at t=0 is?

air is cooled from 273c to 0c,the decrease in rms speed is about

Differentiate between plane mirror and spherical mirror?

Who invented the rotating magnetic field?

Give three applications of convection of heat .

Why does a compass have a lightweight magnet and a frictionless bearing?

65.Sphere of radius R and made of material of relative density 1.5 has a concentric cavity of radius r. it just floats when placed in a tank full of water. the value of R/r is

why only when the object is placed between the pole and focus is virtual and at any other place is real in a concave mirror?

What are the various forms of enegy conversion which take place when a ball is dropped from a height? Lets consider real scenarios with air drag and friction

In the month of June, on one day the maximum temperature in Delhi was recorded as 108.32 degree Fahrenheit.What is temperaure in degree celsius?

Three ships A, B and C are in motion. The motion of A as seen by B is with speed v towards north east. The motion of B as seen by C is with speed v towards the north-west. Then as seen by A, C will be moving towards:1) north 2) south 3) east 4) west.

Who first discovered the magnetic effect of electricity?

134.find out the electic field at the centre of hemisphere with the charge sigma C/m2 on the sphere

19. When force F and 3F are exerted on similar area, then the ratio of pressure will be ?

If the angle of incidence is 60 degree for an incident ray on a surface, then what is the angle of reflection?

A particle is moving from origin towards the north direction for 1km. Again in north-east direction for 1km and then towards west for 1km. Calculate the ratio of displacement to distance.

A load of 10 kN is supported from a pulley which in turn is supported by a rope of cross-sectional area 103 mm2 and modulus of elasticity 103 N/mm2 as shown in the figure. Neglecting friction at the pulley, downward deflection of the load (in mm) is

A football is placed in the path of light as shown below. If the light source is horizontally placed, what will be the shape of the shadow cast by it on the vertical screen?

what is general formula for all the situations of doppler effect in 1)sound waves, 2) light waves

A torch requires 3 cells. Show the arrangement of the cells, with a diagram, inside the torch so that the bulb glows.

What is a potential energy