50278 + Interview Questions in Physics

1.	Answer the following : (a) Why are the connections between the resistors in a meter bridge made of thick copper strips? (b) Why is it generally preferred to obtain the balance point in the middle of the meter bridge wire? (c) Which material is used for the meter bridge wire and why?
Answer» Answer the following : (a) Why are the connections between the resistors in a meter bridge made of thick copper strips? (b) Why is it generally preferred to obtain the balance point in the middle of the meter bridge wire? (c) Which material is used for the meter bridge wire and why?

Discussion

2.	A heart pacing device consists of a coil of 50 turns and radius 1mm just inside the body with a coil of 1000 turns and radius 2 cm placed concentrically and co-axially just outside the body. Calculate the average induced EMF in the internal coil, if a current of 1A in the external coil collapses in 10 milliseconds.
Answer» A heart pacing device consists of a coil of 50 turns and radius 1mm just inside the body with a coil of 1000 turns and radius 2 cm placed concentrically and co-axially just outside the body. Calculate the average induced EMF in the internal coil, if a current of 1A in the external coil collapses in 10 milliseconds.

Discussion

3.	A uniform cylinder of radius r is rotating about its axis at an angular velocity ω0 . It is now placed into a corner as shown in the figure. The coefficient of friction between the wall and the cylinder as well as the ground and the cylinder is μ . If the number of turns n, the cylinder completes before it stops is given by n=ω20r(1+μ2)xπμg(1+μ). Find x. ___
Answer» A uniform cylinder of radius r is rotating about its axis at an angular velocity $ω_{0}$ . It is now placed into a corner as shown in the figure. The coefficient of friction between the wall and the cylinder as well as the ground and the cylinder is $μ$ . If the number of turns n, the cylinder completes before it stops is given by $n = \frac{ω_{0}^{2} r (1 + μ^{2})}{x π μ g (1 + μ)}$ . Find x. ___

Discussion

4.	The force between two short dipoles separated by a distance r is directly proportional to ?
Answer» The force between two short dipoles separated by a distance r is directly proportional to ?

Discussion

5.	derive an expression showing dual nature of matter
Answer» derive an expression showing dual nature of matter

Discussion

6.	An isolated triple star system consists of two identical stars, each of mass m and a fixed star of mass M. The identical masses revolve around the central star in the same circular orbit of radius r. The two orbiting stars are always at opposite ends of a diameter of the orbit. The time period of revolution of each star around the fixed star is equal to :
Answer» An isolated triple star system consists of two identical stars, each of mass m and a fixed star of mass M. The identical masses revolve around the central star in the same circular orbit of radius r. The two orbiting stars are always at opposite ends of a diameter of the orbit. The time period of revolution of each star around the fixed star is equal to :

Discussion

7.	The ionization potential of the hydrogen atom is 13.6 volt. The energy required to remove an electron from the second orbit of hydrogen is:
Answer» The ionization potential of the hydrogen atom is $13.6 volt$ . The energy required to remove an electron from the second orbit of hydrogen is:

Discussion

8.	One mole of an ideal monoatomic gas is kept in a rigid vessel. The vessel is kept inside a steam chamber whose temperature is 87∘C. Initially, the temperature of the gas is 4∘C. The walls of the vessel have an inner surface of area 500 cm2 and thickness 2 cm. If the temperature of the gas increases to 8∘C in 5.0 seconds, find the thermal conductivity of the material of the walls.
Answer» One mole of an ideal monoatomic gas is kept in a rigid vessel. The vessel is kept inside a steam chamber whose temperature is $87^{\circ} C$ . Initially, the temperature of the gas is $4^{\circ} C$ . The walls of the vessel have an inner surface of area $500 {cm}^{2}$ and thickness $2 cm$ . If the temperature of the gas increases to $8^{\circ} C$ in $5.0 seconds$ , find the thermal conductivity of the material of the walls.

Discussion

9.	A large tank is filled with water (density=103 kg/m3). A small hole is made at a depth of 10 m below water surface. The range of water coming out of the hole is R on the ground. What extra pressure must be applied on the water surface so that the range become 2R ? ( p0=1 atm =105 Pa and g=10 m/s2)
Answer» A large tank is filled with water $(density = 10^{3} {kg/m}^{3}) .$ A small hole is made at a depth of $10 m$ below water surface. The range of water coming out of the hole is $R$ on the ground. What extra pressure must be applied on the water surface so that the range become $2 R$ ? $(p_{0} = 1 atm = 10^{5} Pa$ and $g = 10 {m/s}^{2})$

Discussion

10.	A wheel is subjected to uniform angular acceleration about its axis. Initially its angular velocity is zero. In the first 2 sec it rotates through an angle θ1, in the next 2 sec it rotates through an additional angle θ2. The ratio of θ2θ1 is -
Answer» A wheel is subjected to uniform angular acceleration about its axis. Initially its angular velocity is zero. In the first $2 sec$ it rotates through an angle $θ_{1}$ , in the next $2 sec$ it rotates through an additional angle $θ_{2}$ . The ratio of $\frac{θ_{2}}{θ_{1}}$ is -

Discussion

11.	The system is released from rest. Derive the relation between acceleration of the masses involved.
Answer» The system is released from rest. Derive the relation between acceleration of the masses involved.

Discussion

12.	Three blocks A,B and C of mass m each are arranged in pulley mass system as shown. Coefficient of friction between block A and horizontal surface is equal to 0.5 and a force P acts on ‘A′ in the direction shown. The value of Pmg so that block ‘C′ doesn’t move is
Answer» Three blocks $A, B$ and $C$ of mass $m$ each are arranged in pulley mass system as shown. Coefficient of friction between block $A$ and horizontal surface is equal to $0.5$ and a force $P$ acts on $‘ A^{'}$ in the direction shown. The value of $\frac{P}{m g}$ so that block $‘ C^{'}$ doesn’t move is

Discussion

13.	A physical quantity of the dimensions of length that can be formed out of c, G and e24πϵ0 is [c is velocity of light, G is universal constant of gravitation and e is charge] :
Answer» A physical quantity of the dimensions of length that can be formed out of $c, G and \frac{e^{2}}{4 π ϵ_{0}}$ is [ $c$ is velocity of light, $G$ is universal constant of gravitation and $e$ is charge] :

Discussion

14.	if the angular velocity of a body rotating about an axis is doubled and its moment of inertia is halved, the rotational kinetic energy will change by a factor of:
Answer» if the angular velocity of a body rotating about an axis is doubled and its moment of inertia is halved, the rotational kinetic energy will change by a factor of:

Discussion

15.	A paramagnetic substance of susceptibility 3×10−4 is placed in a magnetic field of 4×10−4Am−1. Then the Intensity of magnetization in the units of Am−1 is
Answer» A paramagnetic substance of susceptibility $3 \times 10^{- 4}$ is placed in a magnetic field of $4 \times 10^{- 4} A m^{- 1}$ . Then the Intensity of magnetization in the units of $A m^{- 1}$ is

Discussion

16.	When fluids of density 2.2 g/cc & 4.8 g/cc are mixed together in equal volumes, then the density of the resulting mixture will be
Answer» When fluids of density $2.2 g/cc & 4.8 g/cc$ are mixed together in equal volumes, then the density of the resulting mixture will be

Discussion

17.	Comment on the correctness of the following two statements. Statement I – Net Electric field strength on a Gaussian surface may change if the charges inside or outside move. Statement II – Electric flux through a Gaussian surface will not change if the charges contained inside do not cross the boundary of the assumed Gaussian surface.
Answer» Comment on the correctness of the following two statements. Statement I – Net Electric field strength on a Gaussian surface may change if the charges inside or outside move. Statement II – Electric flux through a Gaussian surface will not change if the charges contained inside do not cross the boundary of the assumed Gaussian surface.

17.

Comment on the correctness of the following two statements. Statement I – Net Electric field strength on a Gaussian surface may change if the charges inside or outside move. Statement II – Electric flux through a Gaussian surface will not change if the charges contained inside do not cross the boundary of the assumed Gaussian surface.

Answer»

Comment on the correctness of the following two statements.

Statement I – Net Electric field strength on a Gaussian surface may change if the charges inside or outside move.

Statement II – Electric flux through a Gaussian surface will not change if the charges contained inside do not cross the boundary of the assumed Gaussian surface.

Discussion

18.	Why is the Base very thin in a transistor?
Answer» Why is the Base very thin in a transistor?

Discussion

19.	The displacement - time (x−t) graph of a particle executing simple harmonic motion is shown in figure. The correct variation of net force F acting on the particle as a function of time is
Answer» The displacement - time $(x - t)$ graph of a particle executing simple harmonic motion is shown in figure. The correct variation of net force $F$ acting on the particle as a function of time is

Discussion

20.	A rocket of mass M is launched vertically from the surface of the earth with an initial speed V. Assuming the radius of the earth to be R and negligible air resistance, the maximum height attained by the rocket above the surface of the earth is
Answer» A rocket of mass M is launched vertically from the surface of the earth with an initial speed V. Assuming the radius of the earth to be R and negligible air resistance, the maximum height attained by the rocket above the surface of the earth is

Discussion

21.	A composite rod of wood & iron is rotating about a fixed axis 'A' with an angular velocity of ω. The lengths of the wood and iron portions is l each. Find the emf induced across the iron rod.
Answer» A composite rod of wood & iron is rotating about a fixed axis 'A' with an angular velocity of $ω$ . The lengths of the wood and iron portions is $l$ each. Find the emf induced across the iron rod.

Discussion

22.	Dimensional formula for amplitude of vibration
Answer» Dimensional formula for amplitude of vibration

Discussion

23.	An ideal gas is taken through the cycle ABCA a shown in the P-V diagram. The total work done by the gas during the cycle is
Answer» An ideal gas is taken through the cycle ABCA a shown in the P-V diagram. The total work done by the gas during the cycle is

Discussion

24.	Given NH3(g)+3Cl2(g)→NCl3(g)+3HCl ; ΔH1 N2(g)+3H2(g)→2NH3(g); ΔH2 H2(g) + Cl2(g)→ 2HClg; ΔH3 The heat of formation of NCI3 in terms of ΔH1,ΔH2andΔH3 is
Answer» Given $N H_{3 (g)} + 3 C l_{2 (g)} \to N C l_{3 (g)} + 3 H C l$ ; $Δ H_{1}$ $N_{2 (g)} + 3 H_{2 (g)} \to 2 N H_{3 (g)}$ ; $Δ H_{2}$ $H_{2 (g)}$ + $C l_{2 (g)} \to$ $2 H C l_{g}$ ; $Δ H_{3}$ The heat of formation of $N C I_{3}$ in terms of $Δ H_{1}, Δ H_{2} a n d Δ H_{3}$ is

24.

Given NH3(g)+3Cl2(g)→NCl3(g)+3HCl ; ΔH1 N2(g)+3H2(g)→2NH3(g); ΔH2 H2(g) + Cl2(g)→ 2HClg; ΔH3 The heat of formation of NCI3 in terms of ΔH1,ΔH2andΔH3 is

Answer»

Given $N H_{3 (g)} + 3 C l_{2 (g)} \to N C l_{3 (g)} + 3 H C l$ ; $Δ H_{1}$

$N_{2 (g)} + 3 H_{2 (g)} \to 2 N H_{3 (g)}$ ; $Δ H_{2}$

$H_{2 (g)}$ + $C l_{2 (g)} \to$ $2 H C l_{g}$ ; $Δ H_{3}$

The heat of formation of $N C I_{3}$ in terms of $Δ H_{1}, Δ H_{2} a n d Δ H_{3}$ is

Discussion

25.	Two identical capacitors are connected as shown and having initial charge Q0. Separation between plates of each capacitor is d0. Suddenly, the left plate of upper capacitor and right plate of lower capacitor starts moving with speed v towards left while other plate of each capacitor remains fixed. (given Q0V2d0=10 A). The value of current (in A) in the circuit is
Answer» Two identical capacitors are connected as shown and having initial charge $Q_{0}$ . Separation between plates of each capacitor is $d_{0}$ . Suddenly, the left plate of upper capacitor and right plate of lower capacitor starts moving with speed $v$ towards left while other plate of each capacitor remains fixed. (given $\frac{Q_{0} V}{2 d_{0}} = 10 A$ ). The value of current (in $A$ ) in the circuit is

Discussion

26.	What is the angle between two forces of equal magnitude such that their resultant is one-fourth as much as either of the original forces?
Answer» What is the angle between two forces of equal magnitude such that their resultant is one-fourth as much as either of the original forces?

Discussion

27.	A body is moving in a circle with a speed of 1 m/s. This speed increases at a constant rate of 2 m/s every second. Assume that the radius of the circle described is 25 m. The total acceleration of the body after 2 s is
Answer» A body is moving in a circle with a speed of $1 m/s$ . This speed increases at a constant rate of $2 m/s$ every second. Assume that the radius of the circle described is $25 m$ . The total acceleration of the body after $2 s$ is

Discussion

28.	When two bodies A and B move uniformly towards each other, the distance between them diminishes by 16 m every 10 s. If velocity of body B is reversed, the distance between them will decrease 3 m every 5 s. The magnitude of velocity of B is 10xms−1, then x is
Answer» When two bodies $A$ and $B$ move uniformly towards each other, the distance between them diminishes by $16 m$ every $10 s$ . If velocity of body $B$ is reversed, the distance between them will decrease $3 m$ every $5 s$ . The magnitude of velocity of $B$ is $\frac{10}{x} m s^{- 1}$ , then $x$ is

Discussion

29.	What is the net flux of the uniform electric field through a cube of side 20 cm oriented so that its faces are parallel to the coordinate planes?
Answer» What is the net flux of the uniform electric field through a cube of side 20 cm oriented so that its faces are parallel to the coordinate planes?

Discussion

30.	A particle is projected with a velocity u at two different angles which are complementary to each other. If H1 and H2 are the heights attained by them in each case, find the range of the particle.
Answer» A particle is projected with a velocity $u$ at two different angles which are complementary to each other. If $H_{1}$ and $H_{2}$ are the heights attained by them in each case, find the range of the particle.

Discussion

31.	The equation of the line making 53∘ with positive x−axis and passing through (2,4) is [Hint:- tan53∘=43]
Answer» The equation of the line making $53^{\circ}$ with positive $x - a x i s$ and passing through $(2, 4)$ is [Hint:- $tan 53^{\circ} = \frac{4}{3}$ ]

Discussion

32.	Why does water rise in a capillary tube?
Answer» Why does water rise in a capillary tube?

Discussion

33.	A light rod of length L can revolve in a vertical circle around point O. The rod carries two equal masses of mass m each such that one mass is connected at the end of the rod and the second mass is fixed at the middle of the rod. u is the velocity imparted to the end P to deflect the rod to the horizontal position. Again mass m in the middle of the rod is removed and mass at end P is doubled. Now v is the velocity imparted to end P to deflect it to the horizontal position. Then (uv)2 is
Answer» A light rod of length $L$ can revolve in a vertical circle around point $O$ . The rod carries two equal masses of mass $m$ each such that one mass is connected at the end of the rod and the second mass is fixed at the middle of the rod. $u$ is the velocity imparted to the end $P$ to deflect the rod to the horizontal position. Again mass $m$ in the middle of the rod is removed and mass at end $P$ is doubled. Now $v$ is the velocity imparted to end $P$ to deflect it to the horizontal position. Then ${(\frac{u}{v})}^{2}$ is

Discussion

34.	An LCR series circuit is at resonance with 10v each across L, C & R. If the resistance is halved, the respective voltage across L, C & R are a) 10v, 10v & 5v. b) 10v, 10v & 10v. c) 20v, 20v & 5v d) 20v, 20v & 10v MTG finger tips. Chapter ac . Que.no. 63. Answers.d
Answer» An LCR series circuit is at resonance with 10v each across L, C & R. If the resistance is halved, the respective voltage across L, C & R are a) 10v, 10v & 5v. b) 10v, 10v & 10v. c) 20v, 20v & 5v d) 20v, 20v & 10v MTG finger tips. Chapter ac . Que.no. 63. Answers.d

34.

An LCR series circuit is at resonance with 10v each across L, C & R. If the resistance is halved, the respective voltage across L, C & R are a) 10v, 10v & 5v. b) 10v, 10v & 10v. c) 20v, 20v & 5v d) 20v, 20v & 10v MTG finger tips. Chapter ac . Que.no. 63. Answers.d

Answer»

An LCR series circuit is at resonance with 10v each across L, C & R. If the resistance is halved, the respective voltage across L, C & R are

a) 10v, 10v & 5v. b) 10v, 10v & 10v. c) 20v, 20v & 5v

d) 20v, 20v & 10v

MTG finger tips. Chapter ac . Que.no. 63. Answers.d

Discussion

35.	During an experiment, an ideal gas is found to obey an additional law pV² = constant.The gas is initially at temperature T and volume V. Find temperature when it expandsto 2V.
Answer» During an experiment, an ideal gas is found to obey an additional law pV² = constant.The gas is initially at temperature T and volume V. Find temperature when it expandsto 2V.

Discussion

36.	A magnetic needle is lying in equilibrium in a uniform magnetic field B. To rotate it through 60o, we need to spend energy W. How much torque needs to be applied to keep it in that position?
Answer» A magnetic needle is lying in equilibrium in a uniform magnetic field B. To rotate it through 60^o, we need to spend energy W. How much torque needs to be applied to keep it in that position?

Discussion

37.	Masses M1,M2 and M3 are connected by strings of negligible mass which pass over massless and frictionless pulleys P1 and P2 as shown in fig. The masses move such that the portion of the string between P1 and P2 is parallel to the inclined plane and the portion of the string between P2 and M3 is horizontal. The masses M2 and M3 are 4.0 kg each and the coefficient of kinetic friction between the masses and the surface is 0.25. The inclined plane makes an angle of 37∘ with the horizontal. If the mass M1 moves downwards with a uniform velocity. find the mass of M1 in kg.
Answer» Masses $M_{1}, M_{2}$ and $M_{3}$ are connected by strings of negligible mass which pass over massless and frictionless pulleys $P_{1}$ and $P_{2}$ as shown in fig. The masses move such that the portion of the string between $P_{1}$ and $P_{2}$ is parallel to the inclined plane and the portion of the string between $P_{2}$ and $M_{3}$ is horizontal. The masses $M_{2}$ and $M_{3}$ are $4.0 k g$ each and the coefficient of kinetic friction between the masses and the surface is $0.25.$ The inclined plane makes an angle of $37^{\circ}$ with the horizontal. If the mass $M_{1}$ moves downwards with a uniform velocity. find the mass of $M_{1}$ in $kg$ .

Discussion

38.	I understood that momentum is defined as product of mass and velocity But what is the meaning of 'change in momentum'? Like it made no sense to me.. How can momentum change once the body is in motion? Does the mass and velocity change or does there occur a simple change in motion? If it is change in motion then why not term it change in motion instead of change in momentum? Please explain this concept of 'change in momentum' to me im detail.
Answer» I understood that momentum is defined as product of mass and velocity But what is the meaning of 'change in momentum'? Like it made no sense to me.. How can momentum change once the body is in motion? Does the mass and velocity change or does there occur a simple change in motion? If it is change in motion then why not term it change in motion instead of change in momentum? Please explain this concept of 'change in momentum' to me im detail.

Discussion

39.	A train is moving along a horizontal track. A pendulum suspended from the roof of the train makes an angle of 5o with the vertical. The acceleration of the train is
Answer» A train is moving along a horizontal track. A pendulum suspended from the roof of the train makes an angle of 5^o with the vertical. The acceleration of the train is

Discussion

40.	Explain why the capacitance decrease when the dielectric medium is removed from between the plates.
Answer» Explain why the capacitance decrease when the dielectric medium is removed from between the plates.

Discussion

41.	A stone thrown upward with a speed u from the top of the tower reaches the ground with a velocity 3u. The height of the tower is
Answer» A stone thrown upward with a speed $u$ from the top of the tower reaches the ground with a velocity $3 u$ . The height of the tower is

Discussion

42.	Two springs A and B have force constants k1 and k2 respectively. The ratio of work done on A to that done on B when they are stretched by the same force is
Answer» Two springs A and B have force constants $k_{1}$ and $k_{2}$ respectively. The ratio of work done on A to that done on B when they are stretched by the same force is

Discussion

43.	Can a body have a charge a) 0.32X10^-18C b)0.64X10^-20C c)4.8X10^-21C Please explain in detail with a solution
Answer» Can a body have a charge a) 0.32X10^-18C b)0.64X10^-20C c)4.8X10^-21C Please explain in detail with a solution

43.

Can a body have a charge a) 0.32X10^-18C b)0.64X10^-20C c)4.8X10^-21C Please explain in detail with a solution

Answer»

Can a body have a charge a) 0.32X10^-18C

b)0.64X10^-20C

c)4.8X10^-21C

Please explain in detail with a solution

Discussion

44.	Find the minimum value of coefficient of friction between the 4 kg block and the surface for the system to be at rest for the figure shown.
Answer» Find the minimum value of coefficient of friction between the $4 k g$ block and the surface for the system to be at rest for the figure shown.

Discussion

45.	An electric dipole is at the centre of a hollow sphere of radius r, where Q is the charge and d is the distance between the two charges of the dipole. The total normal electric flux through the sphere
Answer» An electric dipole is at the centre of a hollow sphere of radius r, where Q is the charge and d is the distance between the two charges of the dipole. The total normal electric flux through the sphere

Discussion

46.	The sound from a very high burst of fireworks takes 5 s to arrive at the observer. The burst occurs 1662 m above the observer and travels vertically through two stratifier layers of air, the top one of thickness d1 at 0∘C and the bottom one of thickness d2 at 20∘C. Then (assume velocity of sound at 0∘C is 330 m/s)
Answer» The sound from a very high burst of fireworks takes 5 s to arrive at the observer. The burst occurs 1662 m above the observer and travels vertically through two stratifier layers of air, the top one of thickness $d_{1}$ at $0^{\circ} C$ and the bottom one of thickness $d_{2}$ at $20^{\circ} C$ . Then (assume velocity of sound at $0^{\circ} C$ is 330 m/s)

Discussion

47.	A solid cone has a height of 20 cm. Find the distance of center of mass of the cone from the center of the base of the cone.
Answer» A solid cone has a height of $20 cm$ . Find the distance of center of mass of the cone from the center of the base of the cone.

Discussion

48.	The disk of radius 5 cm is cut from the uniform disc of radius 10 cm in such a way that the edge of the hole touches the edge of the disc. What is the distance of the center of mass of the remaining portion w.r.t the point O ?
Answer» The disk of radius $5 cm$ is cut from the uniform disc of radius $10 cm$ in such a way that the edge of the hole touches the edge of the disc. What is the distance of the center of mass of the remaining portion w.r.t the point $O$ ?

Discussion

49.	To a man walking at the rate of 3 km/h the rain appears to fall vertically. When he increases his speed to 6 km/h, it appears to meet him at an angle of 45∘ with vertical. Find the speed of rain.
Answer» To a man walking at the rate of $3 km/h$ the rain appears to fall vertically. When he increases his speed to $6 km/h$ , it appears to meet him at an angle of $45^{\circ}$ with vertical. Find the speed of rain.

Discussion

50.	In a typical heart, if EDV is 120 ml of blood and ESV is 50 ml of blood, the stroke volume (SV) is
Answer» In a typical heart, if EDV is 120 ml of blood and ESV is 50 ml of blood, the stroke volume (SV) is

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Answer the following : (a) Why are the connections between the resistors in a meter bridge made of thick copper strips? (b) Why is it generally preferred to obtain the balance point in the middle of the meter bridge wire? (c) Which material is used for the meter bridge wire and why?

The force between two short dipoles separated by a distance r is directly proportional to ?

derive an expression showing dual nature of matter

The ionization potential of the hydrogen atom is 13.6 volt. The energy required to remove an electron from the second orbit of hydrogen is:

A large tank is filled with water (density=103 kg/m3). A small hole is made at a depth of 10 m below water surface. The range of water coming out of the hole is R on the ground. What extra pressure must be applied on the water surface so that the range become 2R ? ( p0=1 atm =105 Pa and g=10 m/s2)

A wheel is subjected to uniform angular acceleration about its axis. Initially its angular velocity is zero. In the first 2 sec it rotates through an angle θ1, in the next 2 sec it rotates through an additional angle θ2. The ratio of θ2θ1 is -

The system is released from rest. Derive the relation between acceleration of the masses involved.

Three blocks A,B and C of mass m each are arranged in pulley mass system as shown. Coefficient of friction between block A and horizontal surface is equal to 0.5 and a force P acts on ‘A′ in the direction shown. The value of Pmg so that block ‘C′ doesn’t move is

A physical quantity of the dimensions of length that can be formed out of c, G and e24πϵ0 is [c is velocity of light, G is universal constant of gravitation and e is charge] :

if the angular velocity of a body rotating about an axis is doubled and its moment of inertia is halved, the rotational kinetic energy will change by a factor of:

A paramagnetic substance of susceptibility 3×10−4 is placed in a magnetic field of 4×10−4Am−1. Then the Intensity of magnetization in the units of Am−1 is

When fluids of density 2.2 g/cc &amp; 4.8 g/cc are mixed together in equal volumes, then the density of the resulting mixture will be

Why is the Base very thin in a transistor?

The displacement - time (x−t) graph of a particle executing simple harmonic motion is shown in figure. The correct variation of net force F acting on the particle as a function of time is

A rocket of mass M is launched vertically from the surface of the earth with an initial speed V. Assuming the radius of the earth to be R and negligible air resistance, the maximum height attained by the rocket above the surface of the earth is

A composite rod of wood &amp; iron is rotating about a fixed axis 'A' with an angular velocity of ω. The lengths of the wood and iron portions is l each. Find the emf induced across the iron rod.

Dimensional formula for amplitude of vibration

An ideal gas is taken through the cycle ABCA a shown in the P-V diagram. The total work done by the gas during the cycle is

Given NH3(g)+3Cl2(g)→NCl3(g)+3HCl ; ΔH1 N2(g)+3H2(g)→2NH3(g); ΔH2 H2(g) + Cl2(g)→ 2HClg; ΔH3 The heat of formation of NCI3 in terms of ΔH1,ΔH2andΔH3 is

What is the angle between two forces of equal magnitude such that their resultant is one-fourth as much as either of the original forces?

A body is moving in a circle with a speed of 1 m/s. This speed increases at a constant rate of 2 m/s every second. Assume that the radius of the circle described is 25 m. The total acceleration of the body after 2 s is

When two bodies A and B move uniformly towards each other, the distance between them diminishes by 16 m every 10 s. If velocity of body B is reversed, the distance between them will decrease 3 m every 5 s. The magnitude of velocity of B is 10xms−1, then x is

What is the net flux of the uniform electric field through a cube of side 20 cm oriented so that its faces are parallel to the coordinate planes?

A particle is projected with a velocity u at two different angles which are complementary to each other. If H1 and H2 are the heights attained by them in each case, find the range of the particle.

The equation of the line making 53∘ with positive x−axis and passing through (2,4) is [Hint:- tan53∘=43]

Why does water rise in a capillary tube?

An LCR series circuit is at resonance with 10v each across L, C &amp; R. If the resistance is halved, the respective voltage across L, C &amp; R are a) 10v, 10v &amp; 5v. b) 10v, 10v &amp; 10v. c) 20v, 20v &amp; 5v d) 20v, 20v &amp; 10v MTG finger tips. Chapter ac . Que.no. 63. Answers.d

During an experiment, an ideal gas is found to obey an additional law pV² = constant.The gas is initially at temperature T and volume V. Find temperature when it expandsto 2V.

A magnetic needle is lying in equilibrium in a uniform magnetic field B. To rotate it through 60o, we need to spend energy W. How much torque needs to be applied to keep it in that position?

A train is moving along a horizontal track. A pendulum suspended from the roof of the train makes an angle of 5o with the vertical. The acceleration of the train is

Explain why the capacitance decrease when the dielectric medium is removed from between the plates.

A stone thrown upward with a speed u from the top of the tower reaches the ground with a velocity 3u. The height of the tower is

Two springs A and B have force constants k1 and k2 respectively. The ratio of work done on A to that done on B when they are stretched by the same force is

Can a body have a charge a) 0.32X10^-18C b)0.64X10^-20C c)4.8X10^-21C Please explain in detail with a solution

Find the minimum value of coefficient of friction between the 4 kg block and the surface for the system to be at rest for the figure shown.

An electric dipole is at the centre of a hollow sphere of radius r, where Q is the charge and d is the distance between the two charges of the dipole. The total normal electric flux through the sphere

A solid cone has a height of 20 cm. Find the distance of center of mass of the cone from the center of the base of the cone.

The disk of radius 5 cm is cut from the uniform disc of radius 10 cm in such a way that the edge of the hole touches the edge of the disc. What is the distance of the center of mass of the remaining portion w.r.t the point O ?

To a man walking at the rate of 3 km/h the rain appears to fall vertically. When he increases his speed to 6 km/h, it appears to meet him at an angle of 45∘ with vertical. Find the speed of rain.

In a typical heart, if EDV is 120 ml of blood and ESV is 50 ml of blood, the stroke volume (SV) is

When fluids of density 2.2 g/cc & 4.8 g/cc are mixed together in equal volumes, then the density of the resulting mixture will be

A composite rod of wood & iron is rotating about a fixed axis 'A' with an angular velocity of ω. The lengths of the wood and iron portions is l each. Find the emf induced across the iron rod.

An LCR series circuit is at resonance with 10v each across L, C & R. If the resistance is halved, the respective voltage across L, C & R are a) 10v, 10v & 5v. b) 10v, 10v & 10v. c) 20v, 20v & 5v d) 20v, 20v & 10v MTG finger tips. Chapter ac . Que.no. 63. Answers.d