13232 + Interview Questions in Physics Page 95 InterviewSolution

4701.	On a two lane road,car A is travelling with aspeed of 36kmph.Two cars B and C approach car A in opposite direction with a speed of 54kmph each.At a certain ins†an t,when the dis†an ce AB is equal to AC,both being 1km ,B decides to overtake A before C does. What minimun acceleration of car B is required to avoid an accident?Explain with suitable diagram
Answer» On a two lane road,car A is travelling with aspeed of 36kmph.Two cars B and C approach car A in opposite direction with a speed of 54kmph each.At a certain ins†an t,when the dis†an ce AB is equal to AC,both being 1km ,B decides to overtake A before C does. What minimun acceleration of car B is required to avoid an accident?Explain with suitable diagram

Discussion

4702.	How do refracting telescopes work?
Answer» How do refracting telescopes work?

Discussion

4703.	Derive the expression for work done when-The displacement is in the direction of the force.
Answer» Derive the expression for work done when- The displacement is in the direction of the force.

4703.

Derive the expression for work done when-The displacement is in the direction of the force.

Answer»

Derive the expression for work done when-

The displacement is in the direction of the force.

Discussion

4704.	A ball is thrown with an initial velocity of 20 ms−1. Find the time of flight and the maximum height reached by the body. (g = 10 ms−2)
Answer» A ball is thrown with an initial velocity of 20 $m s^{- 1}$ . Find the time of flight and the maximum height reached by the body. (g = 10 $m s^{- 2}$ )

Discussion

4705.	How can the momentum of an object with a mass of m moving with a velocity if v, represented?
Answer» How can the momentum of an object with a mass of m moving with a velocity if v, represented?

Discussion

4706.	The density of water is 1000 kg/m3 and the density of copper. is 8900 kg/m3. Which of the following statements is incorrect ? (a) The density of a certain volume of copper The density of the same volume of water =8.9 (b) The volume of a certain mass of copperThe volume of the same mass of water =8.9 (c) The weight of a certain volume of copperThe weight of the same volume of water=8.9 (d) The mass of a certain volume of copperThe mass of the same volume of water =8.9
Answer» The density of water is $1000 k g / m^{3}$ and the density of copper. is $8900 k g / m^{3}$ . Which of the following statements is incorrect ? (a) $\frac{The density of a certain volume of copper}{The density of the same volume of water} = 8.9$ (b) $\frac{The volume of a certain mass of copper}{The volume of the same mass of water} = 8.9$ (c) $\frac{The weight of a certain volume of copper}{The weight of the same volume of water} = 8.9$ (d) $\frac{The mass of a certain volume of copper}{The mass of the same volume of water} = 8.9$

4706.

The density of water is 1000 kg/m3 and the density of copper. is 8900 kg/m3. Which of the following statements is incorrect ? (a) The density of a certain volume of copper The density of the same volume of water =8.9 (b) The volume of a certain mass of copperThe volume of the same mass of water =8.9 (c) The weight of a certain volume of copperThe weight of the same volume of water=8.9 (d) The mass of a certain volume of copperThe mass of the same volume of water =8.9

Answer»

The density of water is $1000 k g / m^{3}$ and the density of copper. is $8900 k g / m^{3}$ . Which of the following statements is incorrect ?

(a) $\frac{The density of a certain volume of copper}{The density of the same volume of water} = 8.9$
(b) $\frac{The volume of a certain mass of copper}{The volume of the same mass of water} = 8.9$
(c) $\frac{The weight of a certain volume of copper}{The weight of the same volume of water} = 8.9$
(d) $\frac{The mass of a certain volume of copper}{The mass of the same volume of water} = 8.9$

Discussion

4707.	nta barrometer tube reads 75 cm of Hg. if tube is gradually inclined at an angle of 30 degree with horizontal, keeping the open end in the mercury container, then find the length of mercury column in the barrometer tube.n
Answer» nta barrometer tube reads 75 cm of Hg. if tube is gradually inclined at an angle of 30 degree with horizontal, keeping the open end in the mercury container, then find the length of mercury column in the barrometer tube.n

Discussion

4708.	A particle falling from rest under gravity covers a height H in 5 seconds . If it continues falling then next distance H will be covered in approximately- (1) 2 s (2) 3 s (3) 4s (4) 5 s
Answer» A particle falling from rest under gravity covers a height H in 5 seconds . If it continues falling then next distance H will be covered in approximately- (1) 2 s (2) 3 s (3) 4s (4) 5 s

Discussion

4709.	Consider the following statements about Teri (The Energy and Resources Institute) Which of the above is/are correct?
Answer» Consider the following statements about Teri (The Energy and Resources Institute) Which of the above is/are correct?

4709.

Consider the following statements about Teri (The Energy and Resources Institute) Which of the above is/are correct?

Answer»

Consider the following statements about Teri (The Energy and Resources Institute)

Which of the above is/are correct?

Discussion

4710.	What travels faster- sound or light? Which observation in daily life supports this?
Answer» What travels faster- sound or light? Which observation in daily life supports this?

Discussion

4711.	Find the equivalent resistance between A and B.
Answer» Find the equivalent resistance between $A$ and $B$ .

Discussion

4712.	A simple pendulum of length 40 cm is taken inside a deep mine. Assume for the time being that the mine is 1600 km deep. Calculate the time period of the pendulum there. Radius of the earth = 6400 km.
Answer» A simple pendulum of length 40 cm is taken inside a deep mine. Assume for the time being that the mine is 1600 km deep. Calculate the time period of the pendulum there. Radius of the earth = 6400 km.

Discussion

4713.	Two blocks each of masses m lie on a smooth table. They are attached to two other masses as shown in figure. The pulleys and strings are light. An object O is kept at rest on the table and the sides AB and CD of the two blocks are made reflecting. The acceleration of the images formed in these two reflecting surfaces with respect to each other is:
Answer» Two blocks each of masses $m$ lie on a smooth table. They are attached to two other masses as shown in figure. The pulleys and strings are light. An object $O$ is kept at rest on the table and the sides $AB$ and $CD$ of the two blocks are made reflecting. The acceleration of the images formed in these two reflecting surfaces with respect to each other is:

Discussion

4714.	conductor is a material which allows a current to flow through it. Why then it resist the flow?
Answer» conductor is a material which allows a current to flow through it. Why then it resist the flow?

Discussion

4715.	31. An object suspended by a wire stretches it by 10mm.When object is immersed in a liquid the elongation in wire reduces by 10/3mm.The ratio of relative densities of the object and liquid is
Answer» 31. An object suspended by a wire stretches it by 10mm.When object is immersed in a liquid the elongation in wire reduces by 10/3mm.The ratio of relative densities of the object and liquid is

Discussion

4716.	What is speed. What is the SI unit of speed
Answer» What is speed. What is the SI unit of speed

Discussion

4717.	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

4718.	An object of height h1=2cm is placed perpendicular to the principal axis of a concave mirror of focal length 10cm. The distance of the object from the mirror is 15cm. Find the nature, position and size of the image respectively.
Answer» An object of height $h_{1} = 2 c m$ is placed perpendicular to the principal axis of a concave mirror of focal length 10cm. The distance of the object from the mirror is 15cm. Find the nature, position and size of the image respectively.

Discussion

4719.	What conclusion is drawn regarding the magnetic field at a point if a compass needle at that point rests in any dirction ? Give reason for your answer.
Answer» What conclusion is drawn regarding the magnetic field at a point if a compass needle at that point rests in any dirction ? Give reason for your answer.

Discussion

4720.	The dimension of acceleration is:
Answer» The dimension of acceleration is:

Discussion

4721.	If the radius of cross section of the conductor is increased by 0.1% keeping volume constant; thenpercentage change in the resistance of the conductor is
Answer» If the radius of cross section of the conductor is increased by 0.1% keeping volume constant; thenpercentage change in the resistance of the conductor is

Discussion

4722.	26. An object thrown vertically upward from ground passes the height of 5m twice in interval of 10s. Find its time of flight.
Answer» 26. An object thrown vertically upward from ground passes the height of 5m twice in interval of 10s. Find its time of flight.

Discussion

4723.	A electron intially at rest falls a distance of 1.5 cm in a uniform electric field of magnitude 2 x 10 to the power 4N/C. then what will be the time take by the to fall the diatance is.
Answer» A electron intially at rest falls a distance of 1.5 cm in a uniform electric field of magnitude 2 x 10 to the power 4N/C. then what will be the time take by the to fall the diatance is.

Discussion

4724.	What is measurement? Explain using an example.
Answer» What is measurement? Explain using an example.

Discussion

4725.	A ball is thrown upwards with a velocity of 10 ms−1. Find the maximum height reached by the ball.
Answer» A ball is thrown upwards with a velocity of $10 m s^{- 1}$ . Find the maximum height reached by the ball.

Discussion

4726.	The weight of an object at the centre of the earth of radius R is : (a) zero (b) R times the weight at the surface of the earth (c) infinite (d) 1/R2times the weight at the surface of the earth
Answer» The weight of an object at the centre of the earth of radius R is : (a) zero (b) R times the weight at the surface of the earth (c) infinite (d) $1 / R^{2}$ times the weight at the surface of the earth

Discussion

4727.	(a) What is the difference between the density and relative density of a substance? (b) If the relative density of a substance is 7.1, what will be its density in SI units?
Answer» (a) What is the difference between the density and relative density of a substance? (b) If the relative density of a substance is 7.1, what will be its density in SI units?

Discussion

4728.	A siphon discharges oil of specific gravity 0.8 from a reservoir into open air as shown in figure. The head loss from point 1 to point 2 is V2/g; where V is the velocity of flow in pipe and from point 2 to point 3 is 3V2/2g. The volume flow rate in the siphon is _______lps.7.9
Answer» A siphon discharges oil of specific gravity 0.8 from a reservoir into open air as shown in figure. The head loss from point 1 to point 2 is $V^{2} / g$ ; where $V$ is the velocity of flow in pipe and from point 2 to point 3 is $3 V^{2} / 2 g$ . The volume flow rate in the siphon is _______lps. 7.9

Discussion

4729.	If a new planet is discovered rotating around the sun with its orbital radius double that of earth, then what will be its time period?(In earth days)
Answer» If a new planet is discovered rotating around the sun with its orbital radius double that of earth, then what will be its time period? (In earth days)

Discussion

4730.	With what speed in mileshr must an object be thrown vertically upwards to reach a height of 91.5 m?Take a=9.8ms2
Answer» With what speed in $\frac{m i l e s}{h r}$ must an object be thrown vertically upwards to reach a height of 91.5 m? $T a k e a = 9.8 \frac{m}{s^{2}}$

Discussion

4731.	Question 11Why will a sheet of paper fall slower than one that is crumpled into a ball?
Answer» Question 11 Why will a sheet of paper fall slower than one that is crumpled into a ball?

Discussion

4732.	A hoop and a solid cylinder of same mass and radius are made of a permanent magnetic material with their magneticmoment parallel to their respective axes. But the magnetic moment of hoop is twice of solid cylinder. They are placed in a uniform magnetic field in such a manner that their magnetic moments make a small angle with the field. If the oscillation periods of hoop and cylinder are Th and Tc respectively then
Answer» A hoop and a solid cylinder of same mass and radius are made of a permanent magnetic material with their magnetic moment parallel to their respective axes. But the magnetic moment of hoop is twice of solid cylinder. They are placed in a uniform magnetic field in such a manner that their magnetic moments make a small angle with the field. If the oscillation periods of hoop and cylinder are $T_{h} and T_{c}$ respectively then

Discussion

4733.	33 If intensity of sound is increased by a factor of 30 by how many decibels does the sound level increase?
Answer» 33 If intensity of sound is increased by a factor of 30 by how many decibels does the sound level increase?

Discussion

4734.	If antiproton has a mass equal to proton then why it is not responsible for some mass of atom?
Answer» If antiproton has a mass equal to proton then why it is not responsible for some mass of atom?

Discussion

4735.	An object dropped from a height of 20 m is undergoing free fall. What is its velocity just before it touches the ground? (Take g=10 ms−2)
Answer» An object dropped from a height of $20 m$ is undergoing free fall. What is its velocity just before it touches the ground? (Take $g = 10 m s^{- 2}$ )

Discussion

4736.	121. A system of particles is moving with some initial velocity u. If linear momentum of the system is conserved, then 1) net external force on system must be zero 2) net torque on system must be zero 3) all forces acting on system must be zero 4) both 1 and 3
Answer» 121. A system of particles is moving with some initial velocity u. If linear momentum of the system is conserved, then 1) net external force on system must be zero 2) net torque on system must be zero 3) all forces acting on system must be zero 4) both 1 and 3

Discussion

4737.	19. A particle executes SHM on a staraight line.At two positions,its velocities are u and v while accelerations are 'a' and 'b' respectively (b is greater than a. a and b are positive).The distance between these two positions is
Answer» 19. A particle executes SHM on a staraight line.At two positions,its velocities are u and v while accelerations are 'a' and 'b' respectively (b is greater than a. a and b are positive).The distance between these two positions is

Discussion

4738.	Question 6(iv)A courier-person cycles from a town to a neighbouring suburban area to deliver a parcel to a merchant. His distance from the town at different times is shown by the following graphDid the person stop on his way? Explain.
Answer» Question 6(iv) A courier-person cycles from a town to a neighbouring suburban area to deliver a parcel to a merchant. His distance from the town at different times is shown by the following graph Did the person stop on his way? Explain.

Discussion

4739.	A body starts from rest at time t=0, accelerates uniformly and travels 320 m in 4 s. Find its velocity at time t=10s.
Answer» A body starts from rest at time $t = 0$ , accelerates uniformly and travels $320 m$ in $4 s$ . Find its velocity at time $t = 10 s$ .

Discussion

4740.	A body weighs 200 gf in air and 175 gf when it is completely immersed in water. The buoyancy force acting on it is
Answer» A body weighs 200 gf in air and 175 gf when it is completely immersed in water. The buoyancy force acting on it is

Discussion

4741.	30.If the Momentum of the body increases by 100% then the kinetic energy increases by
Answer» 30.If the Momentum of the body increases by 100% then the kinetic energy increases by

Discussion

4742.	Mention a few real life applications of electromagnets.
Answer» Mention a few real life applications of electromagnets.

Discussion

4743.	The weight of an object on Mars is 348 N. Then what will be the mass of the object ?
Answer» The weight of an object on Mars is 348 N. Then what will be the mass of the object ?

Discussion

4744.	23. Is the weight of an object the same in different parts of the world or does it vary with change in location?
Answer» 23. Is the weight of an object the same in different parts of the world or does it vary with change in location?

Discussion

4745.	A truck running along a straight line increases its speed uniformly from 30 m/s to 60 m/s over a time interval 1 min. The distance travelled during this time interval is :
Answer» A truck running along a straight line increases its speed uniformly from 30 m/s to 60 m/s over a time interval 1 min. The distance travelled during this time interval is :

Discussion

4746.	24. A body of mass M is taken from Earth's surface to a height of infinity then the change in potential energy will be?
Answer» 24. A body of mass M is taken from Earth's surface to a height of infinity then the change in potential energy will be?

Discussion

4747.	A bus decreases its speed from 80 kmh–1 to 60 kmh–1 in 5 s. Find the acceleration of the bus 🚌 . Please describe it how it came.
Answer» A bus decreases its speed from 80 kmh–1 to 60 kmh–1 in 5 s. Find the acceleration of the bus 🚌 . Please describe it how it came.

Discussion

4748.	A micrometre screw gauge has a negative zero error of 0.0018 cm. The main scale reading is 3.6 cm for an object. The baseline coincides with the 45th division of the circular scale. Calculate the true length of the object in mm.36.063
Answer» A micrometre screw gauge has a negative zero error of $0.0018 c m$ . The main scale reading is $3.6 c m$ for an object. The baseline coincides with the $45^{t h}$ division of the circular scale. Calculate the true length of the object in $m m$ . 36.063

Discussion

4749.	In order to increase the resistance of a given wire of uniform cross-section to four times its value, a fraction of its length is stretched uniformly till the full length of wire becomes 3/2 times of the original length. What is the value of this fraction?
Answer» In order to increase the resistance of a given wire of uniform cross-section to four times its value, a fraction of its length is stretched uniformly till the full length of wire becomes $3 / 2$ times of the original length. What is the value of this fraction?

Discussion

4750.	A point source S is placed midway between two converging mirrors having equal focal length f as shown in figure. For which value of a only one image is formed?
Answer» A point source S is placed midway between two converging mirrors having equal focal length $f$ as shown in figure. For which value of $a$ only one image is formed?

Discussion

Explore topic-wise InterviewSolutions in .

How do refracting telescopes work?

Derive the expression for work done when-The displacement is in the direction of the force.

A ball is thrown with an initial velocity of 20 ms−1. Find the time of flight and the maximum height reached by the body. (g = 10 ms−2)

How can the momentum of an object with a mass of m moving with a velocity if v, represented?

nta barrometer tube reads 75 cm of Hg. if tube is gradually inclined at an angle of 30 degree with horizontal, keeping the open end in the mercury container, then find the length of mercury column in the barrometer tube.n

A particle falling from rest under gravity covers a height H in 5 seconds . If it continues falling then next distance H will be covered in approximately- (1) 2 s (2) 3 s (3) 4s (4) 5 s

Consider the following statements about Teri (The Energy and Resources Institute) Which of the above is/are correct?

What travels faster- sound or light? Which observation in daily life supports this?

Find the equivalent resistance between A and B.

A simple pendulum of length 40 cm is taken inside a deep mine. Assume for the time being that the mine is 1600 km deep. Calculate the time period of the pendulum there. Radius of the earth = 6400 km.

conductor is a material which allows a current to flow through it. Why then it resist the flow?

31. An object suspended by a wire stretches it by 10mm.When object is immersed in a liquid the elongation in wire reduces by 10/3mm.The ratio of relative densities of the object and liquid is

What is speed. What is the SI unit of speed

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.

An object of height h1=2cm is placed perpendicular to the principal axis of a concave mirror of focal length 10cm. The distance of the object from the mirror is 15cm. Find the nature, position and size of the image respectively.

What conclusion is drawn regarding the magnetic field at a point if a compass needle at that point rests in any dirction ? Give reason for your answer.

The dimension of acceleration is:

If the radius of cross section of the conductor is increased by 0.1% keeping volume constant; thenpercentage change in the resistance of the conductor is

26. An object thrown vertically upward from ground passes the height of 5m twice in interval of 10s. Find its time of flight.

A electron intially at rest falls a distance of 1.5 cm in a uniform electric field of magnitude 2 x 10 to the power 4N/C. then what will be the time take by the to fall the diatance is.

What is measurement? Explain using an example.

A ball is thrown upwards with a velocity of 10 ms−1. Find the maximum height reached by the ball.

The weight of an object at the centre of the earth of radius R is : (a) zero (b) R times the weight at the surface of the earth (c) infinite (d) 1/R2times the weight at the surface of the earth

(a) What is the difference between the density and relative density of a substance? (b) If the relative density of a substance is 7.1, what will be its density in SI units?

A siphon discharges oil of specific gravity 0.8 from a reservoir into open air as shown in figure. The head loss from point 1 to point 2 is V2/g; where V is the velocity of flow in pipe and from point 2 to point 3 is 3V2/2g. The volume flow rate in the siphon is _______lps.7.9

If a new planet is discovered rotating around the sun with its orbital radius double that of earth, then what will be its time period?(In earth days)

With what speed in mileshr must an object be thrown vertically upwards to reach a height of 91.5 m?Take a=9.8ms2

Question 11Why will a sheet of paper fall slower than one that is crumpled into a ball?

33 If intensity of sound is increased by a factor of 30 by how many decibels does the sound level increase?

If antiproton has a mass equal to proton then why it is not responsible for some mass of atom?

An object dropped from a height of 20 m is undergoing free fall. What is its velocity just before it touches the ground? (Take g=10 ms−2)

121. A system of particles is moving with some initial velocity u. If linear momentum of the system is conserved, then 1) net external force on system must be zero 2) net torque on system must be zero 3) all forces acting on system must be zero 4) both 1 and 3

19. A particle executes SHM on a staraight line.At two positions,its velocities are u and v while accelerations are 'a' and 'b' respectively (b is greater than a. a and b are positive).The distance between these two positions is

Question 6(iv)A courier-person cycles from a town to a neighbouring suburban area to deliver a parcel to a merchant. His distance from the town at different times is shown by the following graphDid the person stop on his way? Explain.

A body starts from rest at time t=0, accelerates uniformly and travels 320 m in 4 s. Find its velocity at time t=10s.

A body weighs 200 gf in air and 175 gf when it is completely immersed in water. The buoyancy force acting on it is

30.If the Momentum of the body increases by 100% then the kinetic energy increases by

Mention a few real life applications of electromagnets.

The weight of an object on Mars is 348 N. Then what will be the mass of the object ?

23. Is the weight of an object the same in different parts of the world or does it vary with change in location?

A truck running along a straight line increases its speed uniformly from 30 m/s to 60 m/s over a time interval 1 min. The distance travelled during this time interval is :

24. A body of mass M is taken from Earth's surface to a height of infinity then the change in potential energy will be?

A bus decreases its speed from 80 kmh–1 to 60 kmh–1 in 5 s. Find the acceleration of the bus 🚌 . Please describe it how it came.

A micrometre screw gauge has a negative zero error of 0.0018 cm. The main scale reading is 3.6 cm for an object. The baseline coincides with the 45th division of the circular scale. Calculate the true length of the object in mm.36.063

In order to increase the resistance of a given wire of uniform cross-section to four times its value, a fraction of its length is stretched uniformly till the full length of wire becomes 3/2 times of the original length. What is the value of this fraction?

A point source S is placed midway between two converging mirrors having equal focal length f as shown in figure. For which value of a only one image is formed?

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.