9478 + Interview Questions in Physics Page 32 InterviewSolution

1551.	Which of the following are examples of using streamlined shapes to reduce friction?
Answer» Which of the following are examples of using streamlined shapes to reduce friction?

Discussion

1552.	What is normal ray? Definition 1.5marks
Answer» What is normal ray? Definition 1.5marks

Discussion

1553.	An astronomer discovered a new planet rotating on its axis and revolving around a star. He discovered that the star was about the same size as the sun. He studied the planet and discovered the following.• Average distance from the star: 145 million km• Time to orbit the star: 256 days• Time of rotation on axis: 10 hours• Axis of rotation: Perpendicular to the plane of its orbit• Water: Strong possibility of presence of water Compare the planet with the earth on the following points.1. Length of an year2. Length of 1 day and 1 night3. Seasons4.Whether there is possibility of life
Answer» An astronomer discovered a new planet rotating on its axis and revolving around a star. He discovered that the star was about the same size as the sun. He studied the planet and discovered the following. • Average distance from the star: 145 million km • Time to orbit the star: 256 days • Time of rotation on axis: 10 hours • Axis of rotation: Perpendicular to the plane of its orbit • Water: Strong possibility of presence of water Compare the planet with the earth on the following points. 1. Length of an year 2. Length of 1 day and 1 night 3. Seasons 4.Whether there is possibility of life

Discussion

1554.	An arrangement having two carbon rods kept in a conducting liquid in a vessel is known as : (a) rechargeable cell (b) storage cell (c) biological cell (d) electrolytic cell
Answer» An arrangement having two carbon rods kept in a conducting liquid in a vessel is known as : (a) rechargeable cell (b) storage cell (c) biological cell (d) electrolytic cell

Discussion

1555.	1.Pure water obtained from river, sea, well etc. always contains hydrogen and oxygen in ratio (by mass) of? explanation required.
Answer» 1.Pure water obtained from river, sea, well etc. always contains hydrogen and oxygen in ratio (by mass) of? explanation required.

Discussion

1556.	If the density of air molecules is more in the given region, then ______.
Answer» If the density of air molecules is more in the given region, then ______.

Discussion

1557.	Two point charges +8q and -2q are located at x=0 and x=L respectively. The location of a point on the x-axis at which the net electric field due to these two point charges is zero is:
Answer» Two point charges $+ 8 q$ and - $2 q$ are located at $x = 0$ and $x = L$ respectively. The location of a point on the x-axis at which the net electric field due to these two point charges is zero is:

Discussion

1558.	6. If two circular cylinders of equal volumes have their Heights in the ratio 1: 2 then the ratio of their radii is
Answer» 6. If two circular cylinders of equal volumes have their Heights in the ratio 1: 2 then the ratio of their radii is

Discussion

1559.	What is dynamic friction
Answer» What is dynamic friction

Discussion

1560.	The given figure shows a block of mass 300 kg which is placed on a surface. If the length of the block ‘l’ is 1.5 m, breadth of the block ‘b’ is 1 m and height of the block ‘h’ is 0.5 m. What is the pressure at the bottom surface of the block?
Answer» The given figure shows a block of mass 300 kg which is placed on a surface. If the length of the block ‘l’ is 1.5 m, breadth of the block ‘b’ is 1 m and height of the block ‘h’ is 0.5 m. What is the pressure at the bottom surface of the block?

1560.

The given figure shows a block of mass 300 kg which is placed on a surface. If the length of the block ‘l’ is 1.5 m, breadth of the block ‘b’ is 1 m and height of the block ‘h’ is 0.5 m. What is the pressure at the bottom surface of the block?

Answer»

The given figure shows a block of mass 300 kg which is placed on a surface. If the length of the block ‘l’ is 1.5 m, breadth of the block ‘b’ is 1 m and height of the block ‘h’ is 0.5 m. What is the pressure at the bottom surface of the block?

Discussion

1561.	A container with 1 kg of water in it is kept in sunlight, which causes the water to get warmer than the surroundings. The average energy per unit time per unit area received due to the sunlight is 700 W/m2 and it is absorbed by the water over an effective area of 0.05 m2. Assuming that the heat loss from the water to the surroundings is governed by Newton’s law of cooling, the difference (in ℃) in the temperature of water and the surroundings after a long time will be _____ (Ignore effect of the container, and take constant for Newton’s law of cooling = 0.001 s−1, Heat capacity of water = 4200 J kg−1K−1)
Answer» A container with $1 kg$ of water in it is kept in sunlight, which causes the water to get warmer than the surroundings. The average energy per unit time per unit area received due to the sunlight is $700 {W/m}^{2}$ and it is absorbed by the water over an effective area of $0.05 m^{2}$ . Assuming that the heat loss from the water to the surroundings is governed by Newton’s law of cooling, the difference (in ℃) in the temperature of water and the surroundings after a long time will be _____ (Ignore effect of the container, and take constant for Newton’s law of cooling = $0.001 s^{- 1}$ , Heat capacity of water = $4200 J kg - 1 K^{- 1})$

Discussion

1562.	If the speed of light in air is 3 × 108 m/s and speed of light in water is reduced by a factor of 1.3 when compared with that of the speed of light in air. Find out the speed of light in water?
Answer» If the speed of light in air is 3 $\times$ $10^{8}$ m/s and speed of light in water is reduced by a factor of 1.3 when compared with that of the speed of light in air. Find out the speed of light in water?

Discussion

1563.	Four children were asked to arrange forces due to rolling, static and sliding frictions in a decreasing order. (a) Rolling, Static, Sliding (b) Rolling, Sliding, Static (c) Static, Sliding, Rolling (d) Sliding, Static, Rolling
Answer» Four children were asked to arrange forces due to rolling, static and sliding frictions in a decreasing order. (a) Rolling, Static, Sliding (b) Rolling, Sliding, Static (c) Static, Sliding, Rolling (d) Sliding, Static, Rolling

Discussion

1564.	Question 19Establish the relationship between speed of sound, its wavelength and frequency. If velocity of sound in air is 340ms−1, Calculate(i) wavelength when frequency is 256 Hz.(ii) frequency when wavelength is 0.85 m.
Answer» Question 19 Establish the relationship between speed of sound, its wavelength and frequency. If velocity of sound in air is $340 m s^{- 1}$ , Calculate (i) wavelength when frequency is 256 Hz. (ii) frequency when wavelength is 0.85 m.

Discussion

1565.	Why do heavy vehicles have board tires?
Answer» Why do heavy vehicles have board tires?

Discussion

1566.	Sun and earth revolve around a common mass with common period of revolution T.If Ms and Me be masses of Sun and Earth and a be distance of separation,prove that: Ms+Me=(42G)(a3T2)
Answer» Sun and earth revolve around a common mass with common period of revolution T.If Ms and Me be masses of Sun and Earth and a be distance of separation,prove that: Ms+Me=(42G)(a3T2)

Discussion

1567.	Are you afraid of the dark? Why?
Answer» Are you afraid of the dark? Why?

Discussion

1568.	how toreduce friction
Answer» how toreduce friction

Discussion

1569.	What do you understand by electrolysis?Explain why aqueous solution of NaCl is capable of conducting electricity while pure water is not ?
Answer» What do you understand by electrolysis? Explain why aqueous solution of NaCl is capable of conducting electricity while pure water is not ?

Discussion

1570.	State one important consequence of each of the following: (a) Rotation of Earth on its axis. (b) Motion of tilted Earth around the Sun.
Answer» State one important consequence of each of the following: (a) Rotation of Earth on its axis. (b) Motion of tilted Earth around the Sun.

1570.

State one important consequence of each of the following: (a) Rotation of Earth on its axis. (b) Motion of tilted Earth around the Sun.

Answer»

State one important consequence of each of the following:

(a) Rotation of Earth on its axis.

(b) Motion of tilted Earth around the Sun.

Discussion

1571.	Let us assume that our galaxy consists of 2.5 × 1011 stars each of one solar mass. How long will a star at a distance of 50,000 ly from the galactic centre take to complete one revolution? Take the diameter of the Milky Way to be 105 ly.
Answer» Let us assume that our galaxy consists of 2.5 × 10¹¹ stars each of one solar mass. How long will a star at a distance of 50,000 ly from the galactic centre take to complete one revolution? Take the diameter of the Milky Way to be 10⁵ ly.

Discussion

1572.	A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature.The length of aluminium rod is (α_{cu}=1.7×10^{-5}K^{-1}and α_{Al} =2.2×10^{-5}K^{-1
Answer» A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature.The length of aluminium rod is (α_{cu}=1.7×10^{-5}K^{-1}and α_{Al} =2.2×10^{-5}K^{-1

Discussion

1573.	assertion: in lake or ocean water does not freeze completely reason : water has minimum volume at 4^° C 1) both are true and reason is correct explanation of the assertion 2) both are true but reason is not a correct explanation of the asserti
Answer» assertion: in lake or ocean water does not freeze completely reason : water has minimum volume at 4^° C 1) both are true and reason is correct explanation of the assertion 2) both are true but reason is not a correct explanation of the asserti

Discussion

1574.	A strip of impure copper metal is given to you. Describe briefly how you will purify it by using the chemical effect of electric current. Draw a labelled diagram of the experimental set up used for this purpose.
Answer» A strip of impure copper metal is given to you. Describe briefly how you will purify it by using the chemical effect of electric current. Draw a labelled diagram of the experimental set up used for this purpose.

Discussion

1575.	2. What is volume strength of water?
Answer» 2. What is volume strength of water?

Discussion

1576.	There are 5×10^21 atoms in a metal sphere. If one electron is removed from 0.01% atoms, what will be the charge on the sphere??
Answer» There are 5×10^21 atoms in a metal sphere. If one electron is removed from 0.01% atoms, what will be the charge on the sphere??

Discussion

1577.	Explain why sliding friction is less than static friction.
Answer» Explain why sliding friction is less than static friction.

Discussion

1578.	The core of electromagnet is :
Answer» The core of electromagnet is :

Discussion

1579.	Question 21Explain how does lightning conductor protect a building from getting struck by lightning.
Answer» Question 21 Explain how does lightning conductor protect a building from getting struck by lightning.

1579.

Question 21Explain how does lightning conductor protect a building from getting struck by lightning.

Answer»

Question 21

Explain how does lightning conductor protect a building from getting struck by lightning.

Discussion

1580.	A book exerts a pressure of 2 Pa on a table due to its weight. If Rahul places an identical book above it, then what would be the pressure (in Pa) on the table?4
Answer» A book exerts a pressure of 2 Pa on a table due to its weight. If Rahul places an identical book above it, then what would be the pressure (in Pa) on the table? 4

Discussion

1581.	A stone dropped from the top of a tower to travel (5/9) of the height of the tower during the last second of its fall.The time of fall is??
Answer» A stone dropped from the top of a tower to travel (5/9) of the height of the tower during the last second of its fall.The time of fall is??

Discussion

1582.	Calculate the pressure exerted by the waters of the Bay of Bengal near Puducherry, at a depth of 11.0 km. (consider density = 1025 kg/m3)
Answer» Calculate the pressure exerted by the waters of the Bay of Bengal near Puducherry, at a depth of 11.0 km. (consider density = $1025 k g / m^{3}$ )

Discussion

1583.	10gm of ice at -20^° C is kept into a calorimeter containing 10gm of water at 10^° C. The specific heat of water is twice that of ice. When equilibrium is reached the calorimeter will contai
Answer» 10gm of ice at -20^° C is kept into a calorimeter containing 10gm of water at 10^° C. The specific heat of water is twice that of ice. When equilibrium is reached the calorimeter will contai

Discussion

1584.	Question 5Identify the circuit (figure) in which the electrical components have been properly connected.(a) (i)(b) (ii)(c) (iii)(d) (iv)
Answer» Question 5 Identify the circuit (figure) in which the electrical components have been properly connected. (a) (i) (b) (ii) (c) (iii) (d) (iv)

Discussion

1585.	Which of the following objects cannot be charged by physical connection?
Answer» Which of the following objects cannot be charged by physical connection?

Discussion

1586.	Q1:- A closed circuit is in the form of a regular hexagon of side a. If the circuit carries current I, what is magnetic induction at the centre of the hexagon?
Answer» Q1:- A closed circuit is in the form of a regular hexagon of side a. If the circuit carries current I, what is magnetic induction at the centre of the hexagon?

Discussion

1587.	What is sound ?
Answer» What is sound ?

Discussion

1588.	With respect to a satellite going around the earth in a circular orbit, which of the following statements are wrong?
Answer» With respect to a satellite going around the earth in a circular orbit, which of the following statements are wrong?

Discussion

1589.	The reading on a clinical thermometer is 32 ∘C. What will be the equivalent value in the kelvin and the fahrenheit scales, respectively?
Answer» The reading on a clinical thermometer is $32^{\circ} C$ . What will be the equivalent value in the kelvin and the fahrenheit scales, respectively?

Discussion

1590.	Mention any one characteristic of the planet Mars.
Answer» Mention any one characteristic of the planet Mars.

Discussion

1591.	Vocal cords are present in ___.
Answer» Vocal cords are present in ___.

Discussion

1592.	What difference will you see if an iron bar were suspended in place of the bar magnet?
Answer» What difference will you see if an iron bar were suspended in place of the bar magnet?

Discussion

1593.	A plane mirror placed at the distance of 12.5cm from the f of concave mirror of R 20 cm fixed where the object can be place b/w the two mirror so that first image in the both mirror coincide.
Answer» A plane mirror placed at the distance of 12.5cm from the f of concave mirror of R 20 cm fixed where the object can be place b/w the two mirror so that first image in the both mirror coincide.

Discussion

1594.	The average speed of a bicycle, an athlete and a car are 18 kmph, 7 ms−1 and 2 km min−1 respectively. Which of the three is the fastest and which is the lowest? [2 MARKS]
Answer» The average speed of a bicycle, an athlete and a car are $18 k m p h$ , $7 m s^{- 1}$ and $2 k m m i n^{- 1}$ respectively. Which of the three is the fastest and which is the lowest? [2 MARKS]

Discussion

1595.	Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light years away from the Earth? [3 MARKS]
Answer» Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light years away from the Earth? [3 MARKS]

Discussion

1596.	DerivAtion of kinetic energy of rolling motion
Answer» DerivAtion of kinetic energy of rolling motion

Discussion

1597.	A rigid rod is resting with each end touching against 2 perpendicular rods parallel to the coordinate axes. What will be the direction of the normal force due toj each rod?
Answer» A rigid rod is resting with each end touching against 2 perpendicular rods parallel to the coordinate axes. What will be the direction of the normal force due toj each rod?

Discussion

1598.	(a) What is a virtual image? (b) When is a virtual formed? [3 MARKS]
Answer» (a) What is a virtual image? (b) When is a virtual formed? [3 MARKS]

Discussion

1599.	Are concave and convex only two types of curved mirror?Is there any curved mirror apart from these two?
Answer» Are concave and convex only two types of curved mirror? Is there any curved mirror apart from these two?

Discussion

1600.	what is reflection of light
Answer» what is reflection of light

Discussion

Explore topic-wise InterviewSolutions in .

Which of the following are examples of using streamlined shapes to reduce friction?

What is normal ray? Definition 1.5marks

An arrangement having two carbon rods kept in a conducting liquid in a vessel is known as : (a) rechargeable cell (b) storage cell (c) biological cell (d) electrolytic cell

1.Pure water obtained from river, sea, well etc. always contains hydrogen and oxygen in ratio (by mass) of? explanation required.

If the density of air molecules is more in the given region, then ______.

Two point charges +8q and -2q are located at x=0 and x=L respectively. The location of a point on the x-axis at which the net electric field due to these two point charges is zero is:

6. If two circular cylinders of equal volumes have their Heights in the ratio 1: 2 then the ratio of their radii is

What is dynamic friction

The given figure shows a block of mass 300 kg which is placed on a surface. If the length of the block ‘l’ is 1.5 m, breadth of the block ‘b’ is 1 m and height of the block ‘h’ is 0.5 m. What is the pressure at the bottom surface of the block?​

If the speed of light in air is 3 × 108 m/s and speed of light in water is reduced by a factor of 1.3 when compared with that of the speed of light in air. Find out the speed of light in water?

Four children were asked to arrange forces due to rolling, static and sliding frictions in a decreasing order. (a) Rolling, Static, Sliding (b) Rolling, Sliding, Static (c) Static, Sliding, Rolling (d) Sliding, Static, Rolling

Question 19Establish the relationship between speed of sound, its wavelength and frequency. If velocity of sound in air is 340ms−1, Calculate(i) wavelength when frequency is 256 Hz.(ii) frequency when wavelength is 0.85 m.

Why do heavy vehicles have board tires?

Sun and earth revolve around a common mass with common period of revolution T.If Ms and Me be masses of Sun and Earth and a be distance of separation,prove that: Ms+Me=(42G)(a3T2)

Are you afraid of the dark? Why?

how toreduce friction

What do you understand by electrolysis?Explain why aqueous solution of NaCl is capable of conducting electricity while pure water is not ?

State one important consequence of each of the following: (a) Rotation of Earth on its axis. (b) Motion of tilted Earth around the Sun.

Let us assume that our galaxy consists of 2.5 × 1011 stars each of one solar mass. How long will a star at a distance of 50,000 ly from the galactic centre take to complete one revolution? Take the diameter of the Milky Way to be 105 ly.

A copper rod of 88 cm and an aluminium rod of unknown length have their increase in length independent of increase in temperature.The length of aluminium rod is (α_{cu}=1.7×10^{-5}K^{-1}and α_{Al} =2.2×10^{-5}K^{-1

assertion: in lake or ocean water does not freeze completely reason : water has minimum volume at 4^° C 1) both are true and reason is correct explanation of the assertion 2) both are true but reason is not a correct explanation of the asserti

A strip of impure copper metal is given to you. Describe briefly how you will purify it by using the chemical effect of electric current. Draw a labelled diagram of the experimental set up used for this purpose.

2. What is volume strength of water?

There are 5×10^21 atoms in a metal sphere. If one electron is removed from 0.01% atoms, what will be the charge on the sphere??

Explain why sliding friction is less than static friction.

The core of electromagnet is :

Question 21Explain how does lightning conductor protect a building from getting struck by lightning.

A book exerts a pressure of 2 Pa on a table due to its weight. If Rahul places an identical book above it, then what would be the pressure (in Pa) on the table?4

A stone dropped from the top of a tower to travel (5/9) of the height of the tower during the last second of its fall.The time of fall is??

Calculate the pressure exerted by the waters of the Bay of Bengal near Puducherry, at a depth of 11.0 km. (consider density = 1025 kg/m3)

10gm of ice at -20^° C is kept into a calorimeter containing 10gm of water at 10^° C. The specific heat of water is twice that of ice. When equilibrium is reached the calorimeter will contai

Question 5Identify the circuit (figure) in which the electrical components have been properly connected.(a) (i)(b) (ii)(c) (iii)(d) (iv)

Which of the following objects cannot be charged by physical connection?

Q1:- A closed circuit is in the form of a regular hexagon of side a. If the circuit carries current I, what is magnetic induction at the centre of the hexagon?

What is sound ?

With respect to a satellite going around the earth in a circular orbit, which of the following statements are wrong?

The reading on a clinical thermometer is 32 ∘C. What will be the equivalent value in the kelvin and the fahrenheit scales, respectively?

Mention any one characteristic of the planet Mars.

Vocal cords are present in ___.

What difference will you see if an iron bar were suspended in place of the bar magnet?

A plane mirror placed at the distance of 12.5cm from the f of concave mirror of R 20 cm fixed where the object can be place b/w the two mirror so that first image in the both mirror coincide.

The average speed of a bicycle, an athlete and a car are 18 kmph, 7 ms−1 and 2 km min−1 respectively. Which of the three is the fastest and which is the lowest? [2 MARKS]

Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light years away from the Earth? [3 MARKS]

DerivAtion of kinetic energy of rolling motion

A rigid rod is resting with each end touching against 2 perpendicular rods parallel to the coordinate axes. What will be the direction of the normal force due toj each rod?

(a) What is a virtual image? (b) When is a virtual formed? [3 MARKS]

Are concave and convex only two types of curved mirror?Is there any curved mirror apart from these two?

what is reflection of light

The given figure shows a block of mass 300 kg which is placed on a surface. If the length of the block ‘l’ is 1.5 m, breadth of the block ‘b’ is 1 m and height of the block ‘h’ is 0.5 m. What is the pressure at the bottom surface of the block?