13232 + Interview Questions in Physics Page 11 InterviewSolution

501.	Rank the following substances in decreasing order of heat of combustion most exothermic to least exothermic.
Answer» Rank the following substances in decreasing order of heat of combustion most exothermic to least exothermic.

Discussion

502.	The initial velocity of a bullet is 15 m/s. It hits a wooden plank and penetrates it to 10 cm in 3 sec before coming to rest. Find the total retarding force offered by the plank on the bullet.
Answer» The initial velocity of a bullet is 15 m/s. It hits a wooden plank and penetrates it to 10 cm in 3 sec before coming to rest. Find the total retarding force offered by the plank on the bullet.

Discussion

503.	Find the angle of dip at a position other than pole and equator
Answer» Find the angle of dip at a position other than pole and equator

Discussion

504.	The magnetic field line passing through the centre of a circular current carrying conductor is
Answer» The magnetic field line passing through the centre of a circular current carrying conductor is

Discussion

505.	A motorist accelerates from rest to a velocity of 90 km hr−1 in 15 seconds. What is the average acceleration of the car?
Answer» A motorist accelerates from rest to a velocity of $90 k m h r^{- 1}$ in $15$ seconds. What is the average acceleration of the car?

Discussion

506.	Mention a few uses of ultrasonic sounds.
Answer» Mention a few uses of ultrasonic sounds.

Discussion

507.	(i) Distinguish between longitudinal and transverse waves.(ii) Are sound waves longitudinal or transverse?
Answer» (i) Distinguish between longitudinal and transverse waves. (ii) Are sound waves longitudinal or transverse?

Discussion

508.	A pendulum has a frequency of 5 vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from a cliff after 8 vibrations of the pendulum. If the velocity of the sound in air is 340 m/s, what is the distance between the cliff and the observer?
Answer» A pendulum has a frequency of 5 vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from a cliff after 8 vibrations of the pendulum. If the velocity of the sound in air is 340 m/s, what is the distance between the cliff and the observer?

508.

A pendulum has a frequency of 5 vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from a cliff after 8 vibrations of the pendulum. If the velocity of the sound in air is 340 m/s, what is the distance between the cliff and the observer?

Answer»

A pendulum has a frequency of 5 vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from a cliff after 8 vibrations of the pendulum.

If the velocity of the sound in air is 340 m/s, what is the distance between the cliff and the observer?

Discussion

509.	Statement I : Fossil fuels are renewable source of energy.Statement II: Renewable sources are collected from resources which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat.
Answer» Statement I : Fossil fuels are renewable source of energy. Statement II: Renewable sources are collected from resources which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat.

Discussion

510.	A force of 24N gives an acceleration of 4m/s^2 to mass m1 and mass m2 an acceleration of 6m/s^2.What acceleration would it give if both the masses are tied together?
Answer» A force of 24N gives an acceleration of 4m/s^2 to mass m1 and mass m2 an acceleration of 6m/s^2.What acceleration would it give if both the masses are tied together?

Discussion

511.	A car decreases its speed from 80 kmhr−1 to 60 kmhr−1 in 5 seconds. The acceleration of the car is:
Answer» A car decreases its speed from $80 k m h r^{- 1}$ to $60 k m h r^{- 1}$ in $5$ seconds. The acceleration of the car is:

Discussion

512.	Two wires A and B of circular cross section are made of the same metal and have equal lengths, but the resistance of write a is four times greater than that of write B. Find the ratio of their cross sectional areas.
Answer» Two wires A and B of circular cross section are made of the same metal and have equal lengths, but the resistance of write a is four times greater than that of write B. Find the ratio of their cross sectional areas.

Discussion

513.	Difference between specific gravity and relative density.
Answer» Difference between specific gravity and relative density.

Discussion

514.	31.If point object is placed at the focus of a concave mirror and m is lateral magnification obtained in the size of image, then 1) m=0 2)m>1 3)m
Answer» 31.If point object is placed at the focus of a concave mirror and m is lateral magnification obtained in the size of image, then 1) m=0 2)m>1 3)m<<1 4)m tends to minus infinity

Discussion

515.	A wooden block floats in glycerine in such a way that it's 2/5th volume remains above the surface.if relative density of wood is 0.78, calculate the relative density of glycerine.
Answer» A wooden block floats in glycerine in such a way that it's 2/5th volume remains above the surface.if relative density of wood is 0.78, calculate the relative density of glycerine.

Discussion

516.	A particle is moving with a uniform acceleration. Its Its displacement at any instant t is given by s=10t+4.9t°2 . What os initial velocityVelocity at t=3 second andUniform acceleration
Answer» A particle is moving with a uniform acceleration. Its Its displacement at any instant t is given by s=10t+4.9t°2 . What os initial velocity Velocity at t=3 second and Uniform acceleration

Discussion

517.	A thin uniform rod of mass 1 kg and length 0.3 mis smoothly hinged at one end. The rod is released from horizontal position and allowed to rotate invertical plane. The angular velocity of the rod when it becomes vertical is (g 10 m/s2)10(1) 5/3 rad/srad/s(2)3(4) 10/3 rad/s(3)/10 rad/s
Answer» A thin uniform rod of mass 1 kg and length 0.3 mis smoothly hinged at one end. The rod is released from horizontal position and allowed to rotate invertical plane. The angular velocity of the rod when it becomes vertical is (g 10 m/s2)10(1) 5/3 rad/srad/s(2)3(4) 10/3 rad/s(3)/10 rad/s

Discussion

518.	What is the magnitude of the net force acting on the box?
Answer» What is the magnitude of the net force acting on the box?

Discussion

519.	A box is resting on the floor. To move it, a variable force is applied. A force'F' is applied it does not moves. Again a force '2F' is applied it does not moves.At last a force '3F' is applied then it moves. What is the value of the limiting friction
Answer» A box is resting on the floor. To move it, a variable force is applied. A force'F' is applied it does not moves. Again a force '2F' is applied it does not moves.At last a force '3F' is applied then it moves. What is the value of the limiting friction

Discussion

520.	Two masses m1 and m2 are suspended from the ends of a light string passing over a frictionless pulley. If the pulley is pulled up with an acceleration 'g', then the tension in the string is?
Answer» Two masses m1 and m2 are suspended from the ends of a light string passing over a frictionless pulley. If the pulley is pulled up with an acceleration 'g', then the tension in the string is?

Discussion

521.	A bullet of mass m is fired from a gun of mass M. The recoiling gun compress a spring of force constant k by a distance d. Then the velocity of the bullet is :-
Answer» A bullet of mass m is fired from a gun of mass M. The recoiling gun compress a spring of force constant k by a distance d. Then the velocity of the bullet is :-

Discussion

522.	if mass of earth decreases by 25% and its radius increases by 50% then acceleration due to gravity at its surface decreases by nearly?
Answer» if mass of earth decreases by 25% and its radius increases by 50% then acceleration due to gravity at its surface decreases by nearly?

Discussion

523.	A body is thrown vertically upwards and takes 5 seconds to reach naximum height. The distance travelled by the body will be same in (1) 1st and 10th second (2) 2nd and 8th second (3) 4th and 6th second (4) both 2 and 3
Answer» A body is thrown vertically upwards and takes 5 seconds to reach naximum height. The distance travelled by the body will be same in (1) 1st and 10th second (2) 2nd and 8th second (3) 4th and 6th second (4) both 2 and 3

Discussion

524.	When we Strike a metal glass/bell does all the molecules of the glass vibrate? Can this vibration come across the forces of attraction and break the glass/ metal bell?
Answer» When we Strike a metal glass/bell does all the molecules of the glass vibrate? Can this vibration come across the forces of attraction and break the glass/ metal bell?

Discussion

525.	A wire of length 'l' has a resistance 'r'. This wire is stretched to twice its original length. Find the new resistance.
Answer» A wire of length 'l' has a resistance 'r'. This wire is stretched to twice its original length. Find the new resistance.

Discussion

526.	दुकानदारऔर ड्राइवर केसामने अप्पूकी क्या स्थितिहै? वेदोनों उसकोदेखकर पहलेपरेशान होतेहैं, फिरहँसते हैं। कारणबताइए।
Answer» दुकानदार और ड्राइवर के सामने अप्पू की क्या स्थिति है? वे दोनों उसको देखकर पहले परेशान होते हैं, फिर हँसते हैं। कारण बताइए।

Discussion

527.	मगध निवासी किसी भी प्रकार से शासन व्यवस्था में हस्तक्षेप करने से क्यों कतराते हैं?
Answer» मगध निवासी किसी भी प्रकार से शासन व्यवस्था में हस्तक्षेप करने से क्यों कतराते हैं?

Discussion

528.	Question 40Why does moon have very cold and very hot temperature variations e.g., from -190∘C to 110∘C even though it is at the same distance from the sun as the earth is?
Answer» Question 40 Why does moon have very cold and very hot temperature variations e.g., from - $190^{\circ}$ C to $110^{\circ}$ C even though it is at the same distance from the sun as the earth is?

Discussion

529.	Express joule in terms of erg.
Answer» Express joule in terms of erg.

Discussion

530.	Why only spherical masses can be treated as point masses?
Answer» Why only spherical masses can be treated as point masses?

Discussion

531.	What is Einstein theory of relativity? Explain in detail.
Answer» What is Einstein theory of relativity? Explain in detail.

Discussion

532.	Carbon, silicon and germanium atoms have four valence electrons each. Their valenceconduction bands are separated by energy band gaps represented by (Edo (Eals andErespectively. Which of the following relationships is true in their case?(2) Ec E)s(4) (E )c< (EA,g'sg/Sig Geg Si
Answer» Carbon, silicon and germanium atoms have four valence electrons each. Their valenceconduction bands are separated by energy band gaps represented by (Edo (Eals andErespectively. Which of the following relationships is true in their case?(2) Ec E)s(4) (E )c< (EA,g'sg/Sig Geg Si

Discussion

533.	A connecting wire as shown in figure carries a current of 0.5 A. Observe the cross-section at A-B for 20 s. How many electrons would pass through this cross-section in 20 s?
Answer» A connecting wire as shown in figure carries a current of $0.5 A$ . Observe the cross-section at A-B for $20 s$ . How many electrons would pass through this cross-section in $20 s$ ?

Discussion

534.	A rocket is launched at an angle 53^° to the horigontal with an initial speed of 100 m/ s . it moves along its initial line of motion with an acceleration of 30 m/s2 for 3 seconds. At this time its engine falls and rocket proceed like a free body. Find the horizontal range.
Answer» A rocket is launched at an angle 53^° to the horigontal with an initial speed of 100 m/ s . it moves along its initial line of motion with an acceleration of 30 m/s2 for 3 seconds. At this time its engine falls and rocket proceed like a free body. Find the horizontal range.

Discussion

535.	How is couple different from torque
Answer» How is couple different from torque

Discussion

536.	ntA thin tube of uniform cross section is sealed at both ends. it lies horizontally the middle 5 centimetre containing Mercury and the two ends containing air at the same pressure p when the tube is held at an angle 60 degree with the vertical,the lengths of air column above and below the Mercury are 46 cm and 44.5 CM respectively calculate pressure p in cm of Mercury ( the temp is constant at 30)n ntn
Answer» ntA thin tube of uniform cross section is sealed at both ends. it lies horizontally the middle 5 centimetre containing Mercury and the two ends containing air at the same pressure p when the tube is held at an angle 60 degree with the vertical,the lengths of air column above and below the Mercury are 46 cm and 44.5 CM respectively calculate pressure p in cm of Mercury ( the temp is constant at 30)n ntn

Discussion

537.	A very diluted saturated solution of a sparingly soluble salt X_3Y_4 has a vapour pressure of 20 mm Hg at temperature T, while pure water exerts a pressure of 20.0126 mm Hg at the same temperature. calculate molality(m) at temperature T
Answer» A very diluted saturated solution of a sparingly soluble salt X_3Y_4 has a vapour pressure of 20 mm Hg at temperature T, while pure water exerts a pressure of 20.0126 mm Hg at the same temperature. calculate molality(m) at temperature T

Discussion

538.	Inertia is the property of a body due to which it opposes any change in its state of rest or uniform motion.( Here why motion is stated as uniform)
Answer» Inertia is the property of a body due to which it opposes any change in its state of rest or uniform motion.( Here why motion is stated as uniform)

Discussion

539.	The length of a uniform rod is 100.0 cm and radius is 1.00 cm. If length is measured with a meter rod having least count 1mm and radius is measured with vernier callipers having least count 0.1 mm, the percentage error in calculated volume of cylinder is
Answer» The length of a uniform rod is 100.0 cm and radius is 1.00 cm. If length is measured with a meter rod having least count 1mm and radius is measured with vernier callipers having least count 0.1 mm, the percentage error in calculated volume of cylinder is

Discussion

540.	How does the loudness of sound produced depend on the vibrating area of the body?
Answer» How does the loudness of sound produced depend on the vibrating area of the body?

Discussion

541.	A body is thrown vertically upwards and rises to a height of 10m. The velocity with which the body was thrown upwards is : (g = 9.8m/s2)
Answer» A body is thrown vertically upwards and rises to a height of 10m. The velocity with which the body was thrown upwards is : (g = 9.8 $m / s^{2}$ )

Discussion

542.	how to open a circuit
Answer» how to open a circuit

Discussion

543.	A bullet having a mass of 10 g and moving with a speed of 1.5 ms−1, penetrates a thick wooden plank of mass 90 g. The plank was initially at rest. The bullet gets embedded in the plank and both move together. Determine their velocity.
Answer» A bullet having a mass of 10 g and moving with a speed of 1.5 $m s^{- 1}$ , penetrates a thick wooden plank of mass 90 g. The plank was initially at rest. The bullet gets embedded in the plank and both move together. Determine their velocity.

Discussion

544.	Match List-I with List-II the following:List-IA. Stoke's TheoremB. Gauss's TheoremC. Divergence TheoremD. Cauchy's integral TheoremList-II1. ∯ D.ds=Q2. ∮f(z)dz=0 3.∭(▽.A)dv=∯A.ds4.∬(▽×A).ds=∮A.dlCodes :
Answer» Match List-I with List-II the following: List-I A. Stoke's Theorem B. Gauss's Theorem C. Divergence Theorem D. Cauchy's integral Theorem List-II 1. $∯$ $D . d s = Q$ 2. $\oint f (z) d z = 0$ 3. $∭ (▽ . A) d v$ = $∯$ $A . d s$ 4. $\iint (▽ \times A) . d s = \oint A . d l$ Codes :

Discussion

545.	Q 11/90 A car accelerates from rest at constant rate2 m/s2 for some time. Then it retards at constant rate4 m/s2 and comes to rest. If the total time of motionbe 3 s, then total distance travelled by car is4 m6 m2 m3 m
Answer» Q 11/90 A car accelerates from rest at constant rate2 m/s2 for some time. Then it retards at constant rate4 m/s2 and comes to rest. If the total time of motionbe 3 s, then total distance travelled by car is4 m6 m2 m3 m

Discussion

546.	How are the wave velocity V, frequency f and wavelength λ of a wave related ? Derive the relationship.
Answer» How are the wave velocity V, frequency f and wavelength $λ$ of a wave related ? Derive the relationship.

Discussion

547.	If 5×1017 electrons passed through the body in 1 s. Find a) Total charge passed b) Rate of flow of charge
Answer» If $5 \times 10^{17}$ electrons passed through the body in 1 s. Find a) Total charge passed b) Rate of flow of charge

Discussion

548.	Two children are at opposite ends of an aluminium rod. One strikes the end of the rod with a stone. Find the ratio of times taken by the sound wave in air and in aluminium to reach the second child.
Answer» Two children are at opposite ends of an aluminium rod. One strikes the end of the rod with a stone. Find the ratio of times taken by the sound wave in air and in aluminium to reach the second child.

Discussion

549.	the force between 2 identical particles is F. six sich particles are kept at vertices of a regular hexagon of side l.Net force on any particle is.
Answer» the force between 2 identical particles is F. six sich particles are kept at vertices of a regular hexagon of side l.Net force on any particle is.

Discussion

550.	Identify the circuit (figure) in which the electrical components have been properly connected.
Answer» Identify the circuit (figure) in which the electrical components have been properly connected.

Discussion

Explore topic-wise InterviewSolutions in .

Rank the following substances in decreasing order of heat of combustion most exothermic to least exothermic.

The initial velocity of a bullet is 15 m/s. It hits a wooden plank and penetrates it to 10 cm in 3 sec before coming to rest. Find the total retarding force offered by the plank on the bullet.

Find the angle of dip at a position other than pole and equator

The magnetic field line passing through the centre of a circular current carrying conductor is

A motorist accelerates from rest to a velocity of 90 km hr−1 in 15 seconds. What is the average acceleration of the car?

Mention a few uses of ultrasonic sounds.

(i) Distinguish between longitudinal and transverse waves.(ii) Are sound waves longitudinal or transverse?

A pendulum has a frequency of 5 vibrations per second. An observer starts the pendulum and fires a gun simultaneously. He hears the echo from a cliff after 8 vibrations of the pendulum. If the velocity of the sound in air is 340 m/s, what is the distance between the cliff and the observer?

Statement I : Fossil fuels are renewable source of energy.Statement II: Renewable sources are collected from resources which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat.

A force of 24N gives an acceleration of 4m/s^2 to mass m1 and mass m2 an acceleration of 6m/s^2.What acceleration would it give if both the masses are tied together?

A car decreases its speed from 80 kmhr−1 to 60 kmhr−1 in 5 seconds. The acceleration of the car is:

Two wires A and B of circular cross section are made of the same metal and have equal lengths, but the resistance of write a is four times greater than that of write B. Find the ratio of their cross sectional areas.

Difference between specific gravity and relative density.

31.If point object is placed at the focus of a concave mirror and m is lateral magnification obtained in the size of image, then 1) m=0 2)m>1 3)m

A wooden block floats in glycerine in such a way that it's 2/5th volume remains above the surface.if relative density of wood is 0.78, calculate the relative density of glycerine.

A particle is moving with a uniform acceleration. Its Its displacement at any instant t is given by s=10t+4.9t°2 . What os initial velocityVelocity at t=3 second andUniform acceleration

A thin uniform rod of mass 1 kg and length 0.3 mis smoothly hinged at one end. The rod is released from horizontal position and allowed to rotate invertical plane. The angular velocity of the rod when it becomes vertical is (g 10 m/s2)10(1) 5/3 rad/srad/s(2)3(4) 10/3 rad/s(3)/10 rad/s

What is the magnitude of the net force acting on the box?

A box is resting on the floor. To move it, a variable force is applied. A force'F' is applied it does not moves. Again a force '2F' is applied it does not moves.At last a force '3F' is applied then it moves. What is the value of the limiting friction

Two masses m1 and m2 are suspended from the ends of a light string passing over a frictionless pulley. If the pulley is pulled up with an acceleration 'g', then the tension in the string is?

A bullet of mass m is fired from a gun of mass M. The recoiling gun compress a spring of force constant k by a distance d. Then the velocity of the bullet is :-

if mass of earth decreases by 25% and its radius increases by 50% then acceleration due to gravity at its surface decreases by nearly?

A body is thrown vertically upwards and takes 5 seconds to reach naximum height. The distance travelled by the body will be same in (1) 1st and 10th second (2) 2nd and 8th second (3) 4th and 6th second (4) both 2 and 3

When we Strike a metal glass/bell does all the molecules of the glass vibrate? Can this vibration come across the forces of attraction and break the glass/ metal bell?

A wire of length 'l' has a resistance 'r'. This wire is stretched to twice its original length. Find the new resistance.

मगध निवासी किसी भी प्रकार से शासन व्यवस्था में हस्तक्षेप करने से क्यों कतराते हैं?

Question 40Why does moon have very cold and very hot temperature variations e.g., from -190∘C to 110∘C even though it is at the same distance from the sun as the earth is?

Express joule in terms of erg.

Why only spherical masses can be treated as point masses?

What is Einstein theory of relativity? Explain in detail.

Carbon, silicon and germanium atoms have four valence electrons each. Their valenceconduction bands are separated by energy band gaps represented by (Edo (Eals andErespectively. Which of the following relationships is true in their case?(2) Ec E)s(4) (E )c< (EA,g'sg/Sig Geg Si

A connecting wire as shown in figure carries a current of 0.5 A. Observe the cross-section at A-B for 20 s. How many electrons would pass through this cross-section in 20 s?

A rocket is launched at an angle 53^° to the horigontal with an initial speed of 100 m/ s . it moves along its initial line of motion with an acceleration of 30 m/s2 for 3 seconds. At this time its engine falls and rocket proceed like a free body. Find the horizontal range.

How is couple different from torque

A very diluted saturated solution of a sparingly soluble salt X_3Y_4 has a vapour pressure of 20 mm Hg at temperature T, while pure water exerts a pressure of 20.0126 mm Hg at the same temperature. calculate molality(m) at temperature T

Inertia is the property of a body due to which it opposes any change in its state of rest or uniform motion.( Here why motion is stated as uniform)

The length of a uniform rod is 100.0 cm and radius is 1.00 cm. If length is measured with a meter rod having least count 1mm and radius is measured with vernier callipers having least count 0.1 mm, the percentage error in calculated volume of cylinder is

How does the loudness of sound produced depend on the vibrating area of the body?

A body is thrown vertically upwards and rises to a height of 10m. The velocity with which the body was thrown upwards is : (g = 9.8m/s2)

how to open a circuit

A bullet having a mass of 10 g and moving with a speed of 1.5 ms−1, penetrates a thick wooden plank of mass 90 g. The plank was initially at rest. The bullet gets embedded in the plank and both move together. Determine their velocity.

Match List-I with List-II the following:List-IA. Stoke's TheoremB. Gauss's TheoremC. Divergence TheoremD. Cauchy's integral TheoremList-II1. ∯ D.ds=Q2. ∮f(z)dz=0 3.∭(▽.A)dv=∯A.ds4.∬(▽×A).ds=∮A.dlCodes :

Q 11/90 A car accelerates from rest at constant rate2 m/s2 for some time. Then it retards at constant rate4 m/s2 and comes to rest. If the total time of motionbe 3 s, then total distance travelled by car is4 m6 m2 m3 m

How are the wave velocity V, frequency f and wavelength λ of a wave related ? Derive the relationship.

If 5×1017 electrons passed through the body in 1 s. Find a) Total charge passed b) Rate of flow of charge

Two children are at opposite ends of an aluminium rod. One strikes the end of the rod with a stone. Find the ratio of times taken by the sound wave in air and in aluminium to reach the second child.

the force between 2 identical particles is F. six sich particles are kept at vertices of a regular hexagon of side l.Net force on any particle is.

Identify the circuit (figure) in which the electrical components have been properly connected.