50278 + Interview Questions in Physics Page 8 InterviewSolution

351.	a pendulem is swinging in a semi circular path and the maximum speed of bob at the lowest position is 7m/s. If g= 9.8 m/s2, the lenght of the pendulem is
Answer» a pendulem is swinging in a semi circular path and the maximum speed of bob at the lowest position is 7m/s. If g= 9.8 m/s2, the lenght of the pendulem is

Discussion

352.	111.In the circuit shown, the key (K) is closed at t =0, the current through the key at the instant t =10-3 In 2, is (a) 2A (b) 8A (c) 4 A (d) zero
Answer» 111.In the circuit shown, the key (K) is closed at t =0, the current through the key at the instant t =10-3 In 2, is (a) 2A (b) 8A (c) 4 A (d) zero

Discussion

353.	A capacitor is charged and then made to discharge through a resistance. The time constant is τ. In what time will the potential difference across the capacitor decrease by 10%?
Answer» A capacitor is charged and then made to discharge through a resistance. The time constant is $τ$ . In what time will the potential difference across the capacitor decrease by $10 %$ ?

Discussion

354.	Two charged conducting spheres of radii r1 and r2 have same electric field near their surfaces. The ratio of their electric potential is
Answer» Two charged conducting spheres of radii $r_{1}$ and $r_{2}$ have same electric field near their surfaces. The ratio of their electric potential is

Discussion

355.	A square loop of wire of side 4 cm is placed 20 cm away from a concave mirror of focal length 8 cm. What is the area enclosed by the image of the wire ?(assume that the center of loop is on the axis of the mirror and the two sides are normal to the mirror)
Answer» A square loop of wire of side 4 cm is placed 20 cm away from a concave mirror of focal length 8 cm. What is the area enclosed by the image of the wire ?(assume that the center of loop is on the axis of the mirror and the two sides are normal to the mirror)

Discussion

356.	128.Two blocks of mass 2 kg and 3 kg are attached to the ends of a string passing over a smooth pulley fixed to the ceiling of the elevator. A man inside the elevator finds the acceleration of the system to be g/4. The acceleration of the elevator is? ?
Answer» 128.Two blocks of mass 2 kg and 3 kg are attached to the ends of a string passing over a smooth pulley fixed to the ceiling of the elevator. A man inside the elevator finds the acceleration of the system to be g/4. The acceleration of the elevator is? ?

Discussion

357.	One mole of an ideal gas whose pressure changes with volume as P=αV where α is constant. The molar heat capacity of the gas is :-(1)R (2)2R (3)3R (4)4R
Answer» One mole of an ideal gas whose pressure changes with volume as P=αV where α is constant. The molar heat capacity of the gas is :- (1)R (2)2R (3)3R (4)4R

Discussion

358.	A constant force P is applied to a car starting from rest. Then if in time t the car travel a distance x, its kinetic energy is proportional to
Answer» A constant force P is applied to a car starting from rest. Then if in time t the car travel a distance x, its kinetic energy is proportional to

Discussion

359.	A light string passing over a frictionless pulley has masses attached to its ends as shown in the figure. The tension in the thread will be
Answer» A light string passing over a frictionless pulley has masses attached to its ends as shown in the figure. The tension in the thread will be

Discussion

360.	The value of tan3x−tan2x−tanxtan3x tan2x tanx is
Answer» The value of $\frac{t a n 3 x - t a n 2 x - t a n x}{t a n 3 x t a n 2 x t a n x}$ is

Discussion

361.	Two identical springs of spring constant k each are connected in series and parallel as shown in figure. A mass M is suspended from them. The ratio of their frequencies of vertical oscillation will be
Answer» Two identical springs of spring constant $k$ each are connected in series and parallel as shown in figure. A mass $M$ is suspended from them. The ratio of their frequencies of vertical oscillation will be

Discussion

362.	A river 5 km wide is flowing at the rate of 2 km/hr. The minimum time taken by a boat to cross the river with a speed 5 km/hr (in still water) is approximately
Answer» A river $5 km$ wide is flowing at the rate of $2 km/hr$ . The minimum time taken by a boat to cross the river with a speed $5 km/hr$ (in still water) is approximately

Discussion

363.	A planet in a distant solar system is 10 times more massive than the earth and its radius is 10 times smaller. Given that the escape velocity from the earth is 11 km/s, the escape velocity from the surface of the planet would be
Answer» A planet in a distant solar system is $10$ times more massive than the earth and its radius is $10$ times smaller. Given that the escape velocity from the earth is $11 km/s$ , the escape velocity from the surface of the planet would be

Discussion

364.	Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describes circular path of radius R1 and R2 respectively. The ratio of mass of X to that of Y is
Answer» Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describes circular path of radius $R_{1}$ and $R_{2}$ respectively. The ratio of mass of X to that of Y is

Discussion

365.	9. A block of mass 2 kg is pushed against a rough verticalwall with a force of 40 N, coefficient of static frictionbeing 0.5. Another horizontal force of 15 N, is appliedon the block in a direction parallel to the wall. Will theblock move ? If yes, in which direction? If no, find thefrictional force exerted by the wall on the block.
Answer» 9. A block of mass 2 kg is pushed against a rough verticalwall with a force of 40 N, coefficient of static frictionbeing 0.5. Another horizontal force of 15 N, is appliedon the block in a direction parallel to the wall. Will theblock move ? If yes, in which direction? If no, find thefrictional force exerted by the wall on the block.

Discussion

366.	The magnitude of change in velocity of a particle having speed v is v during a time interval delta t while moving in a uniform circular motion. The magnitude of average force on the particle is proportio nal to
Answer» The magnitude of change in velocity of a particle having speed v is v during a time interval delta t while moving in a uniform circular motion. The magnitude of average force on the particle is proportio nal to

Discussion

367.	the correct order of electron affinity is 1.Be
Answer» the correct order of electron affinity is 1.Be

Discussion

368.	Let →b=4^i+3^j and →c be two vectors perpendicular to each other in the xy−plane. If →ri, i=1,2,…,n are the vectors in the same plane having projection 1 and 2 along →b and →c respectively and n∑i=1∣∣→ri∣∣2 is equal to k, then the value of k is
Answer» Let $\to b = 4^i + 3^j$ and $\to c$ be two vectors perpendicular to each other in the $x y -$ plane. If $_{i},$ $i = 1, 2, \dots, n$ are the vectors in the same plane having projection $1$ and $2$ along $\to b$ and $\to c$ respectively and $n \sum i = 1 {∣ ∣_{i} ∣ ∣}^{2}$ is equal to $k,$ then the value of $k$ is

Discussion

369.	The acceleration of a particle is given by a=-omega square x an given that x=Asin omega t,the velocity of the particle will be
Answer» The acceleration of a particle is given by a=-omega square x an given that x=Asin omega t,the velocity of the particle will be

Discussion

370.	A body of 1 kg is thrown vertically upwards with an initial velocity (u)=2 m/s, the height at which kinetic energy of the body is (14)th of its original value is (take g=10 m/s2)
Answer» A body of $1 kg$ is thrown vertically upwards with an initial velocity $(u) = 2 m/s$ , the height at which kinetic energy of the body is $(\frac{1}{4})^{th}$ of its original value is (take $g = 10 {m/s}^{2}$ )

Discussion

371.	An objectof size 3.0 cm is placed 14 cm in front of a concave lens of focallength 21 cm. Describe the image produced by the lens. What happensif the object is moved further away from the lens?
Answer» An object of size 3.0 cm is placed 14 cm in front of a concave lens of focal length 21 cm. Describe the image produced by the lens. What happens if the object is moved further away from the lens?

Discussion

372.	Potential energy of a body is given by V=ax12−bx6,. At x=x0, equilibrium is stable & V=V0,. Then, for
Answer» Potential energy of a body is given by $V = \frac{a}{x^{12}} - \frac{b}{x^{6}},$ . At $x = x_{0}$ , equilibrium is stable & $V = V_{0},$ . Then, for

Discussion

373.	A solid ball of metal has a concentric spherical cavity within it. If the ball is heated, the volume of the cavity will
Answer» A solid ball of metal has a concentric spherical cavity within it. If the ball is heated, the volume of the cavity will

373.

A solid ball of metal has a concentric spherical cavity within it. If the ball is heated, the volume of the cavity will

Answer»

A solid ball of metal has a concentric spherical cavity within it. If the ball is heated, the volume of the cavity will

Discussion

374.	In a mixture of N2 and CO2 gases, the partial pressure of CO2 is 1.25 atm. The total pressure of the mixture is 5 atm.Find the mole fraction of N2 in the mixture.
Answer» In a mixture of $N_{2}$ and $C O_{2}$ gases, the partial pressure of $C O_{2}$ is 1.25 atm. The total pressure of the mixture is 5 atm.Find the mole fraction of $N_{2}$ in the mixture.

Discussion

375.	∫ x3dx is equal to ( where c is constant )
Answer» ∫ x3dx is equal to ( where c is constant )

Discussion

376.	ABC is a right angled triangle in which ab= 3cm BC=3cm and right angled at B the three charges are +15 ,-12,-20 micro coulombs placed respectively at A B and C ,the force acting onB is
Answer» ABC is a right angled triangle in which ab= 3cm BC=3cm and right angled at B the three charges are +15 ,-12,-20 micro coulombs placed respectively at A B and C ,the force acting onB is

Discussion

377.	In an experiment of simple pendulum time period measured was 50 sec for 25 vibration when the length of the simple pendulum was taken 100 cm. If the least count of stop watch is 0.1 s and that of meter scale is 0.1 cm. Calculate the maximum percentage error in the measurement of value of g.
Answer» In an experiment of simple pendulum time period measured was 50 sec for 25 vibration when the length of the simple pendulum was taken 100 cm. If the least count of stop watch is 0.1 s and that of meter scale is 0.1 cm. Calculate the maximum percentage error in the measurement of value of g.

Discussion

378.	Twoideal gas thermometers Aand Buse oxygen and hydrogenrespectively. The following observations are made:Temperature Pressure Pressure thermometer A thermometer BTriple-pointof water 1.250 × 105Pa 0.200 × 105PaNormalmelting point 1.797 × 105Pa 0.287 × 105Paofsulphur(a) What is the absolute temperature of normalmelting point of sulphur as read by thermometers Aand B?(b) What do you think is the reason behind theslight difference in answers of thermometers Aand B?(The thermometers are not faulty).What further procedure is needed in the experiment to reduce thediscrepancy between the two readings?
Answer» Two ideal gas thermometers Aand Buse oxygen and hydrogen respectively. The following observations are made: Temperature Pressure Pressure thermometer A thermometer B Triple-point of water 1.250 × 10⁵ Pa 0.200 × 10⁵ Pa Normal melting point 1.797 × 10⁵ Pa 0.287 × 10⁵ Pa of sulphur (a) What is the absolute temperature of normal melting point of sulphur as read by thermometers Aand B? (b) What do you think is the reason behind the slight difference in answers of thermometers Aand B? (The thermometers are not faulty). What further procedure is needed in the experiment to reduce the discrepancy between the two readings?

378.

Twoideal gas thermometers Aand Buse oxygen and hydrogenrespectively. The following observations are made:Temperature Pressure Pressure thermometer A thermometer BTriple-pointof water 1.250 × 105Pa 0.200 × 105PaNormalmelting point 1.797 × 105Pa 0.287 × 105Paofsulphur(a) What is the absolute temperature of normalmelting point of sulphur as read by thermometers Aand B?(b) What do you think is the reason behind theslight difference in answers of thermometers Aand B?(The thermometers are not faulty).What further procedure is needed in the experiment to reduce thediscrepancy between the two readings?

Answer»

Two
ideal gas thermometers Aand Buse oxygen and hydrogen
respectively. The following observations are made:

Temperature Pressure
Pressure

thermometer A
thermometer B

Triple-point
of water 1.250 × 10⁵
Pa 0.200 × 10⁵
Pa

Normal
melting point 1.797 × 10⁵
Pa 0.287 × 10⁵
Pa

of
sulphur

(a) What is the absolute temperature of normal
melting point of sulphur as read by thermometers Aand B?

(b) What do you think is the reason behind the
slight difference in answers of thermometers Aand B?
(The thermometers are not faulty).
What further procedure is needed in the experiment to reduce the
discrepancy between the two readings?

Discussion

379.	An α−particle travels at an angle of 30∘ to a magnetic field of 0.8 T with a velocity of 105 m/s. The magnitude of magnetic force will be -
Answer» An $α -$ particle travels at an angle of $30^{\circ}$ to a magnetic field of $0.8 T$ with a velocity of $10^{5} m/s$ . The magnitude of magnetic force will be -

Discussion

380.	16.A cubical container of lengthlength L is half filled with liquid of density ø and placed on the floor of an elevator accelerating downwards with an acceleration g/2. Now the container is given a horizontal acceleration parallel to one of the horizontal edges. Then (Po is atmospheric pressure) A) pressure at the centre of the base will remain unchanged upto a certain value of horizontal acceleration. B) the horizontal acceleration for which liquid overflow takes place is g/2 C) the maximum gauge pressure at the bottom surface when liquid is about to overflow is Po + øgL/2 D) the maximum pressure at the bottom surface when liquid is about to overflow is Po.
Answer» 16.A cubical container of lengthlength L is half filled with liquid of density ø and placed on the floor of an elevator accelerating downwards with an acceleration g/2. Now the container is given a horizontal acceleration parallel to one of the horizontal edges. Then (Po is atmospheric pressure) A) pressure at the centre of the base will remain unchanged upto a certain value of horizontal acceleration. B) the horizontal acceleration for which liquid overflow takes place is g/2 C) the maximum gauge pressure at the bottom surface when liquid is about to overflow is Po + øgL/2 D) the maximum pressure at the bottom surface when liquid is about to overflow is Po.

Discussion

381.	Water from a tap emerges vertically downwards with initial velocity 4 ms−1. The cross-sectional area of the tap is A. The flow is steady and pressure is constant throughout the stream of water. The distance h vertically below the tap, where the cross-sectional area of the stream becomes 23A, is: [Take g=10 m/s2]
Answer» Water from a tap emerges vertically downwards with initial velocity $4 {ms}^{- 1}$ . The cross-sectional area of the tap is $A$ . The flow is steady and pressure is constant throughout the stream of water. The distance $h$ vertically below the tap, where the cross-sectional area of the stream becomes $\frac{2}{3} A$ , is: [Take $g = 10 {m/s}^{2}$ ]

Discussion

382.	What is state of motion?
Answer» What is state of motion?

Discussion

383.	The temperature and the dew point in an open room are 20 ∘C and 10 ∘C. If the room temperature drops to 15 ∘C, what will be the new dew point?
Answer» The temperature and the dew point in an open room are $20^{\circ} C$ and $10^{\circ} C$ . If the room temperature drops to $15^{\circ} C$ , what will be the new dew point?

Discussion

384.	3.The moment of inertia of the plate in fig(a) about the axis shown is I. The moment of inertia of the hexagonal plate of the same material shown in figure(b) about the axis given in the figure (b) is
Answer» 3.The moment of inertia of the plate in fig(a) about the axis shown is I. The moment of inertia of the hexagonal plate of the same material shown in figure(b) about the axis given in the figure (b) is

Discussion

385.	Energy of electron in a orbit of H-atom is
Answer» Energy of electron in a orbit of H-atom is

Discussion

386.	A uniform conductor of resistance R is cut into 20 equal pieces. Half of them are joined in series and the remaining half of them are connected in parallel. If the two combinations are joined in series, the effective resistance of the combination is-
Answer» A uniform conductor of resistance $R$ is cut into $20$ equal pieces. Half of them are joined in series and the remaining half of them are connected in parallel. If the two combinations are joined in series, the effective resistance of the combination is-

Discussion

387.	formula of finding mass when an object travels with light speed
Answer» formula of finding mass when an object travels with light speed

Discussion

388.	A bullet of mass 200 g moving with a velocity of100 ms1, penetrates into a number of wooden plankseach of thickness 2 cm and offering constantretardation. Bullet comes to rest when it just entersthe 25th plank. The magnitude of resistive force offeredby the plank is about
Answer» A bullet of mass 200 g moving with a velocity of 100 ms1, penetrates into a number of wooden planks each of thickness 2 cm and offering constant retardation. Bullet comes to rest when it just enters the 25th plank. The magnitude of resistive force offered by the plank is about

Discussion

389.	27. Which of the following does not possess the same dimensions as that of pressure 1) stress 2) bulk modulus 3) thrust 4) energy density
Answer» 27. Which of the following does not possess the same dimensions as that of pressure 1) stress 2) bulk modulus 3) thrust 4) energy density

Discussion

390.	When a particle is projected at an angle to the horizontal, it has range R and time of flight t1. If the same projectile is projected with the same speed at another angle to have the same range and time of flight t2 then,
Answer» When a particle is projected at an angle to the horizontal, it has range R and time of flight t1. If the same projectile is projected with the same speed at another angle to have the same range and time of flight $t_{2}$ then,

Discussion

391.	Two satellites A and B go round a planet P in circular orbits having radii 4R and R respectively. If the speed of the satellite A is 3V, the speed of the satellite B will be.
Answer» Two satellites A and B go round a planet P in circular orbits having radii 4R and R respectively. If the speed of the satellite A is 3V, the speed of the satellite B will be.

Discussion

392.	(Torque and Angular Momentum) 10, An angular impulse of 20 Nms is applied to a hollow cylinder of mass 2 kg and radius 20 cm. The change in its angular speed is (1) 25 rad/s (3) 250 rad/s (2) 2.5 rad/s (4) 2500 rad/s f mat 1 ka and radius 10 cm
Answer» (Torque and Angular Momentum) 10, An angular impulse of 20 Nms is applied to a hollow cylinder of mass 2 kg and radius 20 cm. The change in its angular speed is (1) 25 rad/s (3) 250 rad/s (2) 2.5 rad/s (4) 2500 rad/s f mat 1 ka and radius 10 cm

Discussion

393.	A particle moves in a straight line along x axis. At t=0 it passes origin with some velocity towards positive x axis. With a=-kx;k is positive constant. The time at which velocity becomes of value at t=0 for the first time is
Answer» A particle moves in a straight line along x axis. At t=0 it passes origin with some velocity towards positive x axis. With a=-kx;k is positive constant. The time at which velocity becomes of value at t=0 for the first time is

Discussion

394.	An 8 pole, DC machine has rated current of 100 A. If the armature is duplex lap wound, then the amount of current that will flow in each path at rated condition is ____ A.6.25
Answer» An 8 pole, DC machine has rated current of 100 A. If the armature is duplex lap wound, then the amount of current that will flow in each path at rated condition is ____ A. 6.25

Discussion

395.	(For simplicity in numerical calculations, take g = 10 m s-2) Give the magnitude and direction of the net force acting on (a) a drop of rain falling down with a constant speed, (b) a cork of mass 10 g floating on water, (c) a kite skillfully held stationary in the sky, (d) a car moving with a constant velocity of 30 km/h on a rough road, (e) a high-speed electron in space far from all material objects, and free of electric and magnetic fields.
Answer» (For simplicity in numerical calculations, take g = 10 m s-2) Give the magnitude and direction of the net force acting on (a) a drop of rain falling down with a constant speed, (b) a cork of mass 10 g floating on water, (c) a kite skillfully held stationary in the sky, (d) a car moving with a constant velocity of 30 km/h on a rough road, (e) a high-speed electron in space far from all material objects, and free of electric and magnetic fields.

Discussion

396.	In the arrangement shown in the figure, the ends P and Q of an inextensible string move downwards with uniform speed u. Pulleys A and B are fixed. What is the speed with which mass M moves up?
Answer» In the arrangement shown in the figure, the ends $P$ and $Q$ of an inextensible string move downwards with uniform speed $u$ . Pulleys $A$ and $B$ are fixed. What is the speed with which mass $M$ moves up?

396.

In the arrangement shown in the figure, the ends P and Q of an inextensible string move downwards with uniform speed u. Pulleys A and B are fixed. What is the speed with which mass M moves up?

Answer»

In the arrangement shown in the figure, the ends $P$ and $Q$ of an inextensible string move downwards with uniform speed $u$ . Pulleys $A$ and $B$ are fixed. What is the speed with which mass $M$ moves up?

Discussion

397.	45.In a resonance pipe the first and second resonances are obtained at depths 23.7 cm and 72.3 cm respectively. Then the end correction will be a- 0.6 cm b- 1.2 cm c- 0.8 cm d- 2.4 cm
Answer» 45.In a resonance pipe the first and second resonances are obtained at depths 23.7 cm and 72.3 cm respectively. Then the end correction will be a- 0.6 cm b- 1.2 cm c- 0.8 cm d- 2.4 cm

Discussion

398.	20. How many iron atoms are present in a stainless steel ball bearing having a radius of 0.254 cm?The stainless steel contains 85.6% iron by weight and has density of 7.75g/cm3 (centimetre cube)
Answer» 20. How many iron atoms are present in a stainless steel ball bearing having a radius of 0.254 cm?The stainless steel contains 85.6% iron by weight and has density of 7.75g/cm3 (centimetre cube)

Discussion

399.	45.A stone thrown upward with a speed u from the top of a tower reach the ground with a velocity 4u. The height of the tower is 1.15 u/2g 2.7u/2g 3. 16u/ g 4. 0
Answer» 45.A stone thrown upward with a speed u from the top of a tower reach the ground with a velocity 4u. The height of the tower is 1.15 u/2g 2.7u/2g 3. 16u/ g 4. 0

Discussion

400.	The equivalent resistance between points A and B is:
Answer» The equivalent resistance between points $A$ and $B$ is:

Discussion

Explore topic-wise InterviewSolutions in .

a pendulem is swinging in a semi circular path and the maximum speed of bob at the lowest position is 7m/s. If g= 9.8 m/s2, the lenght of the pendulem is

111.In the circuit shown, the key (K) is closed at t =0, the current through the key at the instant t =10-3 In 2, is (a) 2A (b) 8A (c) 4 A (d) zero

A capacitor is charged and then made to discharge through a resistance. The time constant is τ. In what time will the potential difference across the capacitor decrease by 10%?

Two charged conducting spheres of radii r1 and r2 have same electric field near their surfaces. The ratio of their electric potential is

A square loop of wire of side 4 cm is placed 20 cm away from a concave mirror of focal length 8 cm. What is the area enclosed by the image of the wire ?(assume that the center of loop is on the axis of the mirror and the two sides are normal to the mirror)

128.Two blocks of mass 2 kg and 3 kg are attached to the ends of a string passing over a smooth pulley fixed to the ceiling of the elevator. A man inside the elevator finds the acceleration of the system to be g/4. The acceleration of the elevator is? ?

One mole of an ideal gas whose pressure changes with volume as P=αV where α is constant. The molar heat capacity of the gas is :-(1)R (2)2R (3)3R (4)4R

A constant force P is applied to a car starting from rest. Then if in time t the car travel a distance x, its kinetic energy is proportional to

A light string passing over a frictionless pulley has masses attached to its ends as shown in the figure. The tension in the thread will be

The value of tan3x−tan2x−tanxtan3x tan2x tanx is

Two identical springs of spring constant k each are connected in series and parallel as shown in figure. A mass M is suspended from them. The ratio of their frequencies of vertical oscillation will be

A river 5 km wide is flowing at the rate of 2 km/hr. The minimum time taken by a boat to cross the river with a speed 5 km/hr (in still water) is approximately

A planet in a distant solar system is 10 times more massive than the earth and its radius is 10 times smaller. Given that the escape velocity from the earth is 11 km/s, the escape velocity from the surface of the planet would be

Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describes circular path of radius R1 and R2 respectively. The ratio of mass of X to that of Y is

The magnitude of change in velocity of a particle having speed v is v during a time interval delta t while moving in a uniform circular motion. The magnitude of average force on the particle is proportio nal to

the correct order of electron affinity is 1.Be

Let →b=4^i+3^j and →c be two vectors perpendicular to each other in the xy−plane. If →ri, i=1,2,…,n are the vectors in the same plane having projection 1 and 2 along →b and →c respectively and n∑i=1∣∣→ri∣∣2 is equal to k, then the value of k is

The acceleration of a particle is given by a=-omega square x an given that x=Asin omega t,the velocity of the particle will be

A body of 1 kg is thrown vertically upwards with an initial velocity (u)=2 m/s, the height at which kinetic energy of the body is (14)th of its original value is (take g=10 m/s2)

An objectof size 3.0 cm is placed 14 cm in front of a concave lens of focallength 21 cm. Describe the image produced by the lens. What happensif the object is moved further away from the lens?

Potential energy of a body is given by V=ax12−bx6,. At x=x0, equilibrium is stable &amp; V=V0,. Then, for

A solid ball of metal has a concentric spherical cavity within it. If the ball is heated, the volume of the cavity will

In a mixture of N2 and CO2­ gases, the partial pressure of CO2 is 1.25 atm. The total pressure of the mixture is 5 atm.Find the mole fraction of N2 in the mixture.

∫ x3dx is equal to ( where c is constant )

ABC is a right angled triangle in which ab= 3cm BC=3cm and right angled at B the three charges are +15 ,-12,-20 micro coulombs placed respectively at A B and C ,the force acting onB is

In an experiment of simple pendulum time period measured was 50 sec for 25 vibration when the length of the simple pendulum was taken 100 cm. If the least count of stop watch is 0.1 s and that of meter scale is 0.1 cm. Calculate the maximum percentage error in the measurement of value of g.

An α−particle travels at an angle of 30∘ to a magnetic field of 0.8 T with a velocity of 105 m/s. The magnitude of magnetic force will be -

What is state of motion?

The temperature and the dew point in an open room are 20 ∘C and 10 ∘C. If the room temperature drops to 15 ∘C, what will be the new dew point?

3.The moment of inertia of the plate in fig(a) about the axis shown is I. The moment of inertia of the hexagonal plate of the same material shown in figure(b) about the axis given in the figure (b) is

Energy of electron in a orbit of H-atom is

A uniform conductor of resistance R is cut into 20 equal pieces. Half of them are joined in series and the remaining half of them are connected in parallel. If the two combinations are joined in series, the effective resistance of the combination is-

formula of finding mass when an object travels with light speed

A bullet of mass 200 g moving with a velocity of100 ms1, penetrates into a number of wooden plankseach of thickness 2 cm and offering constantretardation. Bullet comes to rest when it just entersthe 25th plank. The magnitude of resistive force offeredby the plank is about

27. Which of the following does not possess the same dimensions as that of pressure 1) stress 2) bulk modulus 3) thrust 4) energy density

When a particle is projected at an angle to the horizontal, it has range R and time of flight t1. If the same projectile is projected with the same speed at another angle to have the same range and time of flight t2 then,

Two satellites A and B go round a planet P in circular orbits having radii 4R and R respectively. If the speed of the satellite A is 3V, the speed of the satellite B will be.

(Torque and Angular Momentum) 10, An angular impulse of 20 Nms is applied to a hollow cylinder of mass 2 kg and radius 20 cm. The change in its angular speed is (1) 25 rad/s (3) 250 rad/s (2) 2.5 rad/s (4) 2500 rad/s f mat 1 ka and radius 10 cm

A particle moves in a straight line along x axis. At t=0 it passes origin with some velocity towards positive x axis. With a=-kx;k is positive constant. The time at which velocity becomes of value at t=0 for the first time is

An 8 pole, DC machine has rated current of 100 A. If the armature is duplex lap wound, then the amount of current that will flow in each path at rated condition is ____ A.6.25

In the arrangement shown in the figure, the ends P and Q of an inextensible string move downwards with uniform speed u. Pulleys A and B are fixed. What is the speed with which mass M moves up?

45.In a resonance pipe the first and second resonances are obtained at depths 23.7 cm and 72.3 cm respectively. Then the end correction will be a- 0.6 cm b- 1.2 cm c- 0.8 cm d- 2.4 cm

20. How many iron atoms are present in a stainless steel ball bearing having a radius of 0.254 cm?The stainless steel contains 85.6% iron by weight and has density of 7.75g/cm3 (centimetre cube)

45.A stone thrown upward with a speed u from the top of a tower reach the ground with a velocity 4u. The height of the tower is 1.15 u/2g 2.7u/2g 3. 16u/ g 4. 0

The equivalent resistance between points A and B is:

Potential energy of a body is given by V=ax12−bx6,. At x=x0, equilibrium is stable & V=V0,. Then, for

In a mixture of N2 and CO2 gases, the partial pressure of CO2 is 1.25 atm. The total pressure of the mixture is 5 atm.Find the mole fraction of N2 in the mixture.