50278 + Interview Questions in Physics

1.	A man standing on a road has to hold his umbrella at 60∘ with the horizontal to keep the rain away. He throws the umbrella and starts running at 20 kmh−1 . He finds that raindrops are hitting his head vertically. The actual speed of raindrops is
Answer» A man standing on a road has to hold his umbrella at $60^{\circ}$ with the horizontal to keep the rain away. He throws the umbrella and starts running at $20 k m h^{- 1}$ . He finds that raindrops are hitting his head vertically. The actual speed of raindrops is

Discussion

2.	A particle of mass m=1 kg is moving along the line y=x+2 with speed 2 m/s. The angular momentum of the particle about origin O is
Answer» A particle of mass $m = 1 kg$ is moving along the line $y = x + 2$ with speed $2 m/s$ . The angular momentum of the particle about origin $O$ is

Discussion

3.	Two parallel plate air filled capacitors, each of capacitance C, are joined in series to a battery of emf V. The space between the plates of one of the capacitors is then completely filled up with a uniform dielectric having dielectric constant K. The quantity of charge which flows through the battery is
Answer» Two parallel plate air filled capacitors, each of capacitance $C$ , are joined in series to a battery of emf $V$ . The space between the plates of one of the capacitors is then completely filled up with a uniform dielectric having dielectric constant $K$ . The quantity of charge which flows through the battery is

Discussion

4.	An ideal gas at 300 K occupies a volume of 0.5 m3 at a pressure of 2 atm. The gas expands adiabatically until its volume is 1.2 m3. Next, the gas is compressed isobarically to its original volume. Finally, the pressure is increased isochorically until the gas returns to its initial state. Represent the change on the P-V diagram. Determine the temperature at the end of each transformation; and the work done during the cycle. Assume g = 1.4.
Answer» An ideal gas at 300 K occupies a volume of 0.5 $m^{3}$ at a pressure of 2 atm. The gas expands adiabatically until its volume is 1.2 $m^{3}$ . Next, the gas is compressed isobarically to its original volume. Finally, the pressure is increased isochorically until the gas returns to its initial state. Represent the change on the P-V diagram. Determine the temperature at the end of each transformation; and the work done during the cycle. Assume g = 1.4.

Discussion

5.	A man throws balls (and catches at the same height) with the same speed vertically upwards one after the other at an interval of 2 seconds. What should be the speed of the throw so that more than two balls are in the sky at any time (Given g = 10m/s2)
Answer» A man throws balls (and catches at the same height) with the same speed vertically upwards one after the other at an interval of 2 seconds. What should be the speed of the throw so that more than two balls are in the sky at any time (Given g = $10 m / s^{2}$ )

Discussion

6.	Let P be an interior point of a convex quadrilateral ABCD and K,L,M,N be the midpoints of AB,BC,CD,DA respectively. If area(PKAN)=25,area(PLBK)=36,area(PMDN)=41, then area(PLCM)= is
Answer» Let $P$ be an interior point of a convex quadrilateral $A B C D$ and $K, L, M, N$ be the midpoints of $A B, B C, C D, D A$ respectively. If $area (P K A N) = 25, area (P L B K) = 36, area (P M D N) = 41,$ then $area (P L C M) =$ is

Discussion

7.	A solid hemisphere is mounted on a solid cylinder, both having equal radii. If the whole solid is to have a fixed surface area and the maximum possible volume, then the ratio of the height of the cylinder to the common radius is
Answer» A solid hemisphere is mounted on a solid cylinder, both having equal radii. If the whole solid is to have a fixed surface area and the maximum possible volume, then the ratio of the height of the cylinder to the common radius is

Discussion

8.	An aeroplane has to go from a point A to another point B, 500 km away due 300 east of north. A wind is blowing due north at as speed of 20 m/s. The air-speed of the plane is 150 m/s. (a) Find the directiion in which the pilot should head the plane to reach the point B. (b) Find the time taken by the plane to go from A to B.
Answer» An aeroplane has to go from a point A to another point B, 500 km away due $30^{0}$ east of north. A wind is blowing due north at as speed of 20 m/s. The air-speed of the plane is 150 m/s. (a) Find the directiion in which the pilot should head the plane to reach the point B. (b) Find the time taken by the plane to go from A to B.

8.

An aeroplane has to go from a point A to another point B, 500 km away due 300 east of north. A wind is blowing due north at as speed of 20 m/s. The air-speed of the plane is 150 m/s. (a) Find the directiion in which the pilot should head the plane to reach the point B. (b) Find the time taken by the plane to go from A to B.

Answer»

An aeroplane has to go from a point A to another point B, 500 km away due $30^{0}$ east of north. A wind is blowing due north at as speed of 20 m/s. The air-speed of the plane is 150 m/s.

(a) Find the directiion in which the pilot should head the plane to reach the point B.

(b) Find the time taken by the plane to go from A to B.

Discussion

9.	A vessel of depth 2d cm is half filled with a liquid of refractive index μ1 and the upper half with a liquid of refractive index μ2. The apparent depth of the vessel seen perpendicularly is
Answer» A vessel of depth 2d cm is half filled with a liquid of refractive index $μ_{1}$ and the upper half with a liquid of refractive index $μ_{2}$ . The apparent depth of the vessel seen perpendicularly is

Discussion

10.	In the figure shown below, u=√7gl and mass of the bob is 3 kg. Find the value of tension in the string when angle θ=180∘ [Take g=10 m/s2]
Answer» In the figure shown below, $u = \sqrt{7 g l}$ and mass of the bob is $3 kg$ . Find the value of tension in the string when angle $θ = 180^{\circ}$ [Take $g = 10 {m/s}^{2}$ ]

Discussion

11.	Both blocks of mass m are initially at rest. The left block is given initial velocity u downwards. Then find the displacement in metres of the COM of the two block system
Answer» Both blocks of mass $m$ are initially at rest. The left block is given initial velocity $u$ downwards. Then find the displacement in $metres$ of the $COM$ of the two block system

Discussion

12.	Two trains A and B of length 400 m each are moving on two parallel tracks with a uniform speed of 72 kmh−1 in the same direction, with A ahead of B. The driver of B decides to overtake A and accelerates by 1 m/s2. If after 50 s, the guard of B just brushes past the driver of A, what was the original distance between them?
Answer» Two trains A and B of length 400 m each are moving on two parallel tracks with a uniform speed of $72 k m h^{- 1}$ in the same direction, with A ahead of B. The driver of B decides to overtake A and accelerates by $1 m / s^{2}$ . If after 50 s, the guard of B just brushes past the driver of A, what was the original distance between them?

Discussion

13.	Speed of sound in a gas at 27∘C is 360 m/s. Its speed at 37∘ C is
Answer» Speed of sound in a gas at $27^{\circ} C$ is $360 m/s$ . Its speed at $37^{\circ} C$ is

Discussion

14.	A body is moving up an inclined plane of angle θ with an initial kinetic energy E. The coefficient of friction between the plane and the body is μ. The work done against friction before the body comes to rest is
Answer» A body is moving up an inclined plane of angle $θ$ with an initial kinetic energy E. The coefficient of friction between the plane and the body is $μ$ . The work done against friction before the body comes to rest is

Discussion

15.	Two blocks are connected over a massless pulley as shown in the figure. The mass of block A is 10 kg. If block A slides down the inclined plane at constant speed, then mass of block B in kg is
Answer» Two blocks are connected over a massless pulley as shown in the figure. The mass of block $A$ is $10 kg$ . If block $A$ slides down the inclined plane at constant speed, then mass of block $B$ in $kg$ is

Discussion

16.	A uniformly charged spherical conductor has a radius of 1m and surface charge density 0.8Cm2. The electric field magnitude because of this at a point 1m radially away, from the surface of the sphere is
Answer» A uniformly charged spherical conductor has a radius of 1m and surface charge density $0.8 \frac{C}{m^{2}}$ . The electric field magnitude because of this at a point 1m radially away, from the surface of the sphere is

Discussion

17.	A locomotive of mass m starts moving so that its velocity varies as v=αs2/3, where α is a constant and s is the distance traversed. The total work done by all the forces acting on the locomotive during the first t second after the start of motion is
Answer» A locomotive of mass $m$ starts moving so that its velocity varies as $v = α s^{2 / 3}$ , where $α$ is a constant and $s$ is the distance traversed. The total work done by all the forces acting on the locomotive during the first $t$ second after the start of motion is

Discussion

18.	At what temperature KE of a gas molecules is half of its value at 327∘c?
Answer» At what temperature KE of a gas molecules is half of its value at $327^{\circ} c ?$

Discussion

19.	A parallel beam of light of wavelength 100 nm passes through a sample of atomic hydrogen gas in fground state. (a) Assume that when a photon supplies some of its energy to a hydrogen atom, the rest of the energy appears as another photon moving in the direction of the incident photon. Neglecting the light emitted by the excited hydrogen atoms in the direction of the incident beam,, what wavelengths may be observed in the transmitted beam ? (b) A radition detector is placed near the gas to detect radition coming perpendicular to the incident beam. Find the wavelengths of raditions that may be detected by the detector.
Answer» A parallel beam of light of wavelength 100 nm passes through a sample of atomic hydrogen gas in fground state. (a) Assume that when a photon supplies some of its energy to a hydrogen atom, the rest of the energy appears as another photon moving in the direction of the incident photon. Neglecting the light emitted by the excited hydrogen atoms in the direction of the incident beam,, what wavelengths may be observed in the transmitted beam ? (b) A radition detector is placed near the gas to detect radition coming perpendicular to the incident beam. Find the wavelengths of raditions that may be detected by the detector.

19.

A parallel beam of light of wavelength 100 nm passes through a sample of atomic hydrogen gas in fground state. (a) Assume that when a photon supplies some of its energy to a hydrogen atom, the rest of the energy appears as another photon moving in the direction of the incident photon. Neglecting the light emitted by the excited hydrogen atoms in the direction of the incident beam,, what wavelengths may be observed in the transmitted beam ? (b) A radition detector is placed near the gas to detect radition coming perpendicular to the incident beam. Find the wavelengths of raditions that may be detected by the detector.

Answer»

A parallel beam of light of wavelength 100 nm passes through a sample of atomic hydrogen gas in fground state.

(a) Assume that when a photon supplies some of its energy to a hydrogen atom, the rest of the energy appears as another photon moving in the direction of the incident photon. Neglecting the light emitted by the excited hydrogen atoms in the direction of the incident beam,, what wavelengths may be observed in the transmitted beam ?

(b) A radition detector is placed near the gas to detect radition coming perpendicular to the incident beam. Find the wavelengths of raditions that may be detected by the detector.

Discussion

20.	A wire is stretched so as to change its diameter by 0.25%. The percentage change in resistance is
Answer» A wire is stretched so as to change its diameter by $0.25 %$ . The percentage change in resistance is

Discussion

21.	Neena goes around a circular track that has a diameter of 7 m. If she runs around the entire track for a distance of 50 m, what is her angular displacement?
Answer» Neena goes around a circular track that has a diameter of $7 m$ . If she runs around the entire track for a distance of $50 m$ , what is her angular displacement?

Discussion

22.	Can 6.02210^23 can be represented as 602210^20.why it is not represented as like that
Answer» Can 6.02210^23 can be represented as 602210^20.why it is not represented as like that

Discussion

23.	A sphere, a cube and a thin circular plate, all made of the same material and having the same mass are initially heated to a temperature of 1000∘ C. Which one of these will cool first
Answer» A sphere, a cube and a thin circular plate, all made of the same material and having the same mass are initially heated to a temperature of $1000^{\circ} C$ . Which one of these will cool first

Discussion

24.	Derivation for acceleration due to gravity on its effects of height and depth... Explain plllzzz
Answer» Derivation for acceleration due to gravity on its effects of height and depth... Explain plllzzz

Discussion

25.	If →a=2^i+4^j+3^k,→b=^i+^j+^k, then the scalar product and the angle between them are
Answer» If $\to a = 2^i + 4^j + 3^k, \to b =^i +^j +^k,$ then the scalar product and the angle between them are

Discussion

26.	A crate is on the flat surface of a truck of coefficient of static friction μs=0.8 and coefficient of kinetic friction μk=0.7. The coefficient of kinetic friction between the truck tires and the road surface is 0.9. If the truck suddenly stops from an initial speed of 15 m/s with maximum braking (wheels skidding), determine the displacement of the crate before it comes to rest.
Answer» A crate is on the flat surface of a truck of coefficient of static friction $μ_{s} = 0.8$ and coefficient of kinetic friction $μ_{k} = 0.7$ . The coefficient of kinetic friction between the truck tires and the road surface is $0.9$ . If the truck suddenly stops from an initial speed of $15 m / s$ with maximum braking (wheels skidding), determine the displacement of the crate before it comes to rest.

Discussion

27.	Two blocks of masses 10 kg and 20 kg moving at speeds of 10 m s−1 and 20 m s−1 respectively in opposite directions, approach each other and collide. If the collision is completely inelastic, find the thermal energy developed in the process.
Answer» Two blocks of masses 10 kg and 20 kg moving at speeds of 10 m $s^{- 1}$ and 20 m $s^{- 1}$ respectively in opposite directions, approach each other and collide. If the collision is completely inelastic, find the thermal energy developed in the process.

Discussion

28.	A steel ball is suspended from the ceiling of an accelerating carriage by means of two cords A and B. Determine the acceleration a ( in m/s2) of the carriage which will cause the tension in A to be twice that in B
Answer» A steel ball is suspended from the ceiling of an accelerating carriage by means of two cords $A$ and $B$ . Determine the acceleration $a$ ( in ${m/s}^{2}$ ) of the carriage which will cause the tension in A to be twice that in B

Discussion

29.	the peak voltage in the output of a half-wave diode rectifier fed with a sinusoidal signal without filter is 10 v. the d.c. conponent of the output voltage is ans. 10/π
Answer» the peak voltage in the output of a half-wave diode rectifier fed with a sinusoidal signal without filter is 10 v. the d.c. conponent of the output voltage is ans. 10/π

Discussion

30.	A projectile is fired at speed of 50√2 m/s at an angle of 45∘ from the horizontal. At t=5 s, the projectile breaks into two parts of mass ratio 1:4 and the lighter piece comes to rest immediately. Find the distance from the launching point to the point where the heavier piece lands.
Answer» A projectile is fired at speed of $50 \sqrt{2} m/s$ at an angle of $45^{\circ}$ from the horizontal. At $t = 5 s$ , the projectile breaks into two parts of mass ratio $1 : 4$ and the lighter piece comes to rest immediately. Find the distance from the launching point to the point where the heavier piece lands.

Discussion

31.	The density of a gas at 760 mm pressure and 0∘ temperature is 30g/c.c. If the temperature is kept constant,what will be the density of that gas at 570 mm pressure?
Answer» The density of a gas at 760 mm pressure and $0^{\circ}$ temperature is 30g/c.c. If the temperature is kept constant,what will be the density of that gas at 570 mm pressure?

Discussion

32.	The sphere shown in figure lies on a rough plane when a particle of mass m traveling at a speed v0 collides and sticks with it. If the line of motion of the particle is at a distance 'h' above the plane, find the value of 'h for which the sphere starts pure rolling on the plane. Assume that the mass M of the sphere is large compared to the mass of the particle so that the center of mass of the combined system is not appreciably shifted from the centre of the sphere.
Answer» The sphere shown in figure lies on a rough plane when a particle of mass m traveling at a speed $v_{0}$ collides and sticks with it. If the line of motion of the particle is at a distance 'h' above the plane, find the value of 'h for which the sphere starts pure rolling on the plane. Assume that the mass M of the sphere is large compared to the mass of the particle so that the center of mass of the combined system is not appreciably shifted from the centre of the sphere.

32.

The sphere shown in figure lies on a rough plane when a particle of mass m traveling at a speed v0 collides and sticks with it. If the line of motion of the particle is at a distance 'h' above the plane, find the value of 'h for which the sphere starts pure rolling on the plane. Assume that the mass M of the sphere is large compared to the mass of the particle so that the center of mass of the combined system is not appreciably shifted from the centre of the sphere.

Answer»

The sphere shown in figure lies on a rough plane when a particle of mass m traveling at a speed $v_{0}$ collides and sticks with it. If the line of motion of the particle is at a distance 'h' above the plane, find the value of 'h for which the sphere starts pure rolling on the plane. Assume that the mass M of the sphere is large compared to the mass of the particle so that the center of mass of the combined system is not appreciably shifted from the centre of the sphere.

Discussion

33.	The e.m.f. of a cell is ε and its internal resistance is r. Its terminals are connected to a resistance R. The potential difference between the terminals is 1.6 V for R=4Ω and 1.8 V for R=9Ω. Then,
Answer» The e.m.f. of a cell is ε and its internal resistance is r. Its terminals are connected to a resistance R. The potential difference between the terminals is 1.6 V for $R = 4 Ω$ and 1.8 V for $R = 9 Ω$ . Then,

Discussion

34.	L=Iw is not always true for all bodies (ie. of any shapes).why?
Answer» L=Iw is not always true for all bodies (ie. of any shapes).why?

Discussion

35.	The refractive index of the material of a prism is √2 and the angle of the prism is 30°. One of the two refracting surfaces of the prism is made a mirror facing inwards by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface), if its angle of incidence on the prism is
Answer» The refractive index of the material of a prism is $\sqrt{2}$ and the angle of the prism is 30°. One of the two refracting surfaces of the prism is made a mirror facing inwards by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface), if its angle of incidence on the prism is

35.

The refractive index of the material of a prism is √2 and the angle of the prism is 30°. One of the two refracting surfaces of the prism is made a mirror facing inwards by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface), if its angle of incidence on the prism is

Answer»

The refractive index of the material of a prism is $\sqrt{2}$ and the angle of the prism is 30°. One of the two refracting surfaces of the prism is made a mirror facing inwards by silver coating. A beam of monochromatic light entering the prism from the other face will retrace its path (after reflection from the silvered surface), if its angle of incidence on the prism is

Discussion

36.	A projectile is projected at an angle of 60° to the horizontal with a speed of 60m/s.What will be it's velocity along horizontal.Hence determine the range of the projectile.
Answer» A projectile is projected at an angle of 60° to the horizontal with a speed of 60m/s.What will be it's velocity along horizontal.Hence determine the range of the projectile.

Discussion

37.	Which of the following statements is/are incorrect?
Answer» Which of the following statements is/are incorrect?

37.

Which of the following statements is/are incorrect?

Answer»

Which of the following statements is/are incorrect?

Discussion

38.	A copper wire of length 1.0 m and a steel wire of length 0.5 m having equal cross-sectional areas are joined end to end. The composite wire is stretched by a certain load which stretches the copper wire by 1 mm. If the Young's moduli of copper and steel are 1.0×1011 Nm−2 and 2.0×1011 Nm−2, the total extension of the composite wire is
Answer» A copper wire of length 1.0 m and a steel wire of length 0.5 m having equal cross-sectional areas are joined end to end. The composite wire is stretched by a certain load which stretches the copper wire by 1 mm. If the Young's moduli of copper and steel are $1.0 \times 10^{11} N m^{- 2}$ and $2.0 \times 10^{11} N m^{- 2}$ , the total extension of the composite wire is

Discussion

39.	Which of the following has zero electron density in xy plane?
Answer» Which of the following has zero electron density in xy plane?

Discussion

40.	A car travels from A to B at a speed of 20 km/hr and returns at a speed of 30 km/hr. The average speed of the car for the whole journey is
Answer» A car travels from A to B at a speed of $20 km/hr$ and returns at a speed of $30 km/hr$ . The average speed of the car for the whole journey is

Discussion

41.	Why is the colour of ice white though the colour of water is colourless? give answer according to 5 mark.
Answer» Why is the colour of ice white though the colour of water is colourless? give answer according to 5 mark.

Discussion

42.	A helicopter is flying horizontally at an altitude of 2 km with a speed of 100 ms−1. A packet is dropped from it. The horizontal distance between the point where the packet is dropped and the point where it hits the ground is (g=10 ms−2)
Answer» A helicopter is flying horizontally at an altitude of $2 km$ with a speed of $100 {ms}^{- 1}$ . A packet is dropped from it. The horizontal distance between the point where the packet is dropped and the point where it hits the ground is $(g = 10 {ms}^{- 2})$

Discussion

43.	A charge q is placed at the center of the cube of side l. What is the electric flux passing through two opposite faces of the cube? Ans. 13qε0
Answer» A charge q is placed at the center of the cube of side l. What is the electric flux passing through two opposite faces of the cube? Ans. $\frac{1}{3} \frac{q}{ε_{0}}$

43.

A charge q is placed at the center of the cube of side l. What is the electric flux passing through two opposite faces of the cube? Ans. 13qε0

Answer»

A charge q is placed at the center of the cube of side l. What is the electric flux passing through two opposite faces of the cube?

Ans. $\frac{1}{3} \frac{q}{ε_{0}}$

Discussion

44.	A large insulating thick sheet of thickness 2d carries a uniform charge per unit volume ρ. A particle of mass m, carrying a charge q having a sign opposite to that of the sheet, is released from the surface of the sheet. The sheet does not offer any mechanical resistance to the motion of the particle. Find the oscillation frequency ν of the particle inside the sheet.
Answer» A large insulating thick sheet of thickness $2 d$ carries a uniform charge per unit volume $ρ$ . A particle of mass $m$ , carrying a charge $q$ having a sign opposite to that of the sheet, is released from the surface of the sheet. The sheet does not offer any mechanical resistance to the motion of the particle. Find the oscillation frequency $ν$ of the particle inside the sheet.

Discussion

45.	A candle flame 1.6 cm high is imaged in a ball bearing of diameter 0.4 cm. If the ball bearing is 20 cm away from the flame, find the location and the height of the image.
Answer» A candle flame 1.6 cm high is imaged in a ball bearing of diameter 0.4 cm. If the ball bearing is 20 cm away from the flame, find the location and the height of the image.

Discussion

46.	An ideal gas at 27∘C is compressed adiabatically to 827 of its original volume. If γ=53, then the rise in temperature is
Answer» An ideal gas at $27^{\circ} C$ is compressed adiabatically to $\frac{8}{27}$ of its original volume. If $γ = \frac{5}{3},$ then the rise in temperature is

Discussion

47.	What is the relation between the force function and potential energy function?
Answer» What is the relation between the force function and potential energy function?

Discussion

48.	A car is moving along the north direction with a speed of 10 m/s after some time it change its direction along 53° west north without changing the speed. If mass of car is 500 kg write the change in momentum.
Answer» A car is moving along the north direction with a speed of 10 m/s after some time it change its direction along 53° west north without changing the speed. If mass of car is 500 kg write the change in momentum.

Discussion

49.	If e is the electric field intensity of an electrostatic field then the electrostatic energy density is proportional to 1)e 2)e×e 3)1/e×e 4)e×e×e Answer is 2
Answer» If e is the electric field intensity of an electrostatic field then the electrostatic energy density is proportional to 1)e 2)e×e 3)1/e×e 4)e×e×e Answer is 2

49.

If e is the electric field intensity of an electrostatic field then the electrostatic energy density is proportional to 1)e 2)e×e 3)1/e×e 4)e×e×e Answer is 2

Answer»

If e is the electric field intensity of an electrostatic field then the electrostatic energy density is proportional to

1)e

2)e×e

3)1/e×e

4)e×e×e

Answer is 2

Discussion

50.	The minimum tangential speed of a rotating cylinder, at which the floor below the man may be removed and the man hangs resting against the wall is: [Take g=10 m/s2]
Answer» The minimum tangential speed of a rotating cylinder, at which the floor below the man may be removed and the man hangs resting against the wall is: [Take $g = 10 {m/s}^{2}$ ]

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A man standing on a road has to hold his umbrella at 60∘ with the horizontal to keep the rain away. He throws the umbrella and starts running at 20 kmh−1 . He finds that raindrops are hitting his head vertically. The actual speed of raindrops is

A particle of mass m=1 kg is moving along the line y=x+2 with speed 2 m/s. The angular momentum of the particle about origin O is

A man throws balls (and catches at the same height) with the same speed vertically upwards one after the other at an interval of 2 seconds. What should be the speed of the throw so that more than two balls are in the sky at any time (Given g = 10m/s2)

Let P be an interior point of a convex quadrilateral ABCD and K,L,M,N be the midpoints of AB,BC,CD,DA respectively. If area(PKAN)=25,area(PLBK)=36,area(PMDN)=41, then area(PLCM)= is

A solid hemisphere is mounted on a solid cylinder, both having equal radii. If the whole solid is to have a fixed surface area and the maximum possible volume, then the ratio of the height of the cylinder to the common radius is

A vessel of depth 2d cm is half filled with a liquid of refractive index μ1 and the upper half with a liquid of refractive index μ2. The apparent depth of the vessel seen perpendicularly is

In the figure shown below, u=√7gl and mass of the bob is 3 kg. Find the value of tension in the string when angle θ=180∘ [Take g=10 m/s2]

Both blocks of mass m are initially at rest. The left block is given initial velocity u downwards. Then find the displacement in metres of the COM of the two block system

Speed of sound in a gas at 27∘C is 360 m/s. Its speed at 37∘ C is

A body is moving up an inclined plane of angle θ with an initial kinetic energy E. The coefficient of friction between the plane and the body is μ. The work done against friction before the body comes to rest is

Two blocks are connected over a massless pulley as shown in the figure. The mass of block A is 10 kg. If block A slides down the inclined plane at constant speed, then mass of block B in kg is

A uniformly charged spherical conductor has a radius of 1m and surface charge density 0.8Cm2. The electric field magnitude because of this at a point 1m radially away, from the surface of the sphere is

A locomotive of mass m starts moving so that its velocity varies as v=αs2/3, where α is a constant and s is the distance traversed. The total work done by all the forces acting on the locomotive during the first t second after the start of motion is

At what temperature KE of a gas molecules is half of its value at 327∘c?

A wire is stretched so as to change its diameter by 0.25%. The percentage change in resistance is

Neena goes around a circular track that has a diameter of 7 m. If she runs around the entire track for a distance of 50 m, what is her angular displacement?

Can 6.022*10^23 can be represented as 6022*10^20.why it is not represented as like that

A sphere, a cube and a thin circular plate, all made of the same material and having the same mass are initially heated to a temperature of 1000∘ C. Which one of these will cool first

Derivation for acceleration due to gravity on its effects of height and depth... Explain plllzzz

If →a=2^i+4^j+3^k,→b=^i+^j+^k, then the scalar product and the angle between them are

Two blocks of masses 10 kg and 20 kg moving at speeds of 10 m s−1 and 20 m s−1 respectively in opposite directions, approach each other and collide. If the collision is completely inelastic, find the thermal energy developed in the process.

A steel ball is suspended from the ceiling of an accelerating carriage by means of two cords A and B. Determine the acceleration a ( in m/s2) of the carriage which will cause the tension in A to be twice that in B

the peak voltage in the output of a half-wave diode rectifier fed with a sinusoidal signal without filter is 10 v. the d.c. conponent of the output voltage is ans. 10/π

A projectile is fired at speed of 50√2 m/s at an angle of 45∘ from the horizontal. At t=5 s, the projectile breaks into two parts of mass ratio 1:4 and the lighter piece comes to rest immediately. Find the distance from the launching point to the point where the heavier piece lands.

The density of a gas at 760 mm pressure and 0∘ temperature is 30g/c.c. If the temperature is kept constant,what will be the density of that gas at 570 mm pressure?

The e.m.f. of a cell is ε and its internal resistance is r. Its terminals are connected to a resistance R. The potential difference between the terminals is 1.6 V for R=4Ω and 1.8 V for R=9Ω. Then,

L=Iw is not always true for all bodies (ie. of any shapes).why?

A projectile is projected at an angle of 60° to the horizontal with a speed of 60m/s.What will be it's velocity along horizontal.Hence determine the range of the projectile.

Which of the following statements is/are incorrect?

Which of the following has zero electron density in xy plane?

A car travels from A to B at a speed of 20 km/hr and returns at a speed of 30 km/hr. The average speed of the car for the whole journey is

Why is the colour of ice white though the colour of water is colourless? give answer according to 5 mark.

A helicopter is flying horizontally at an altitude of 2 km with a speed of 100 ms−1. A packet is dropped from it. The horizontal distance between the point where the packet is dropped and the point where it hits the ground is (g=10 ms−2)

A charge q is placed at the center of the cube of side l. What is the electric flux passing through two opposite faces of the cube? Ans. 13qε0

A candle flame 1.6 cm high is imaged in a ball bearing of diameter 0.4 cm. If the ball bearing is 20 cm away from the flame, find the location and the height of the image.

An ideal gas at 27∘C is compressed adiabatically to 827 of its original volume. If γ=53, then the rise in temperature is

What is the relation between the force function and potential energy function?

A car is moving along the north direction with a speed of 10 m/s after some time it change its direction along 53° west north without changing the speed. If mass of car is 500 kg write the change in momentum.

If e is the electric field intensity of an electrostatic field then the electrostatic energy density is proportional to 1)e 2)e×e 3)1/e×e 4)e×e×e Answer is 2

The minimum tangential speed of a rotating cylinder, at which the floor below the man may be removed and the man hangs resting against the wall is: [Take g=10 m/s2]

Can 6.02210^23 can be represented as 602210^20.why it is not represented as like that