50278 + Interview Questions in Physics

1.	12. Two bodies of masses m1 and m2 are initially at rest at infinite distance apart.They are then allowed to move towards each other under mutual gravitational attraction.Their relative velocity of approach at a separation distance r between them.
Answer» 12. Two bodies of masses m1 and m2 are initially at rest at infinite distance apart.They are then allowed to move towards each other under mutual gravitational attraction.Their relative velocity of approach at a separation distance r between them.

Discussion

2.	An inductance of 200πmH, a capacitance of 10−3πF and a resistance of 10 Ω are connected in series with an a.c. source 220 V, 50 Hz. The phase angle of the circuit for the current and voltage source is
Answer» An inductance of $\frac{200}{π} m H$ , a capacitance of $\frac{10^{- 3}}{π} F$ and a resistance of $10 Ω$ are connected in series with an a.c. source 220 V, 50 Hz. The phase angle of the circuit for the current and voltage source is

2.

An inductance of 200πmH, a capacitance of 10−3πF and a resistance of 10 Ω are connected in series with an a.c. source 220 V, 50 Hz. The phase angle of the circuit for the current and voltage source is

Answer»

An inductance of $\frac{200}{π} m H$ , a capacitance of $\frac{10^{- 3}}{π} F$ and a resistance of $10 Ω$ are connected in series with an a.c. source 220 V, 50 Hz. The phase angle of the circuit for the current and voltage source is

Discussion

3.	A body at the end of a spring executes S.H.M. with a period t1, while the corresponding period for another spring is t2. If the period of oscillation with the two springs in series is T, then
Answer» A body at the end of a spring executes S.H.M. with a period $t_{1},$ while the corresponding period for another spring is $t_{2} .$ If the period of oscillation with the two springs in series is $T$ , then

Discussion

4.	The nature of electromagnetic waves Z = is
Answer» The nature of electromagnetic waves Z = is

Discussion

5.	Two racing cars of masses m1 and m2 are moving in circles of radii r1 and r2 respectively. Their speeds are such that each makes a complete circle at the same time t. The ratio of the angular speeds of the first to the second car is 1) r1 :\:r2 2) m1 : m2 3) 1 : 1 4) m1m2 : r1r2
Answer» Two racing cars of masses m1 and m2 are moving in circles of radii r1 and r2 respectively. Their speeds are such that each makes a complete circle at the same time t. The ratio of the angular speeds of the first to the second car is 1) r1 :\:r2 2) m1 : m2 3) 1 : 1 4) m1m2 : r1r2

Discussion

6.	31 Calculate the standard free energy change for the reaction 4 NH3 (g) + 5O2 (g) 4NO (g) + 6 H2O (l) Given that the free energy change for the formation of NH3 (g), NO (g) and H2O (l) are -16.8, +86.7 and -273.2 kJ/mole respectively. Predict the feasibility of the reaction.
Answer» 31 Calculate the standard free energy change for the reaction 4 NH3 (g) + 5O2 (g) 4NO (g) + 6 H2O (l) Given that the free energy change for the formation of NH3 (g), NO (g) and H2O (l) are -16.8, +86.7 and -273.2 kJ/mole respectively. Predict the feasibility of the reaction.

Discussion

7.	One end of a long metallic wire of length l is tied to the ceiling. The other end is tied to a massless spring of spring constant K. A mass (M) hangs freely from the free end of the spring. The area of cross-section and Young's modulus of the wire are a and Y respectively. If the mass is slightly pulled down and released, it will oscillate with a frequency f equal to
Answer» One end of a long metallic wire of length $l$ is tied to the ceiling. The other end is tied to a massless spring of spring constant $K$ . A mass ( $M$ ) hangs freely from the free end of the spring. The area of cross-section and Young's modulus of the wire are $a$ and $Y$ respectively. If the mass is slightly pulled down and released, it will oscillate with a frequency $f$ equal to

Discussion

8.	A radioactive nucleus of mass M emits a photon offrequency v and the nucleus recoils. The recoil\lbrack AIPMT (Prelims)-2011\rbrack energy will be:(1) hv(2) Mc2- hvh2v2(3)2Mc(4) Zero
Answer» A radioactive nucleus of mass M emits a photon offrequency v and the nucleus recoils. The recoil\lbrack AIPMT (Prelims)-2011\rbrack energy will be:(1) hv(2) Mc2- hvh2v2(3)2Mc(4) Zero

Discussion

9.	Forces of 5 N , 12N, 13N are in equilibrium.if sin 23 degree is equal to 5 by 13 then the angle between the 5N and 13N force is
Answer» Forces of 5 N , 12N, 13N are in equilibrium.if sin 23 degree is equal to 5 by 13 then the angle between the 5N and 13N force is

Discussion

10.	A particle moves along x-axis such that the directionof its motion is always towards the origin. If x, v anda respectively represent position, velocity andacceleration of the particle, then choose the correctoption.(1) xv = 0 (2) xv > 0(3) xa < 0 (4) xv < 0
Answer» A particle moves along x-axis such that the direction of its motion is always towards the origin. If x, v and a respectively represent position, velocity and acceleration of the particle, then choose the correct option. (1) xv = 0 (2) xv > 0 (3) xa < 0 (4) xv < 0

Discussion

11.	Check that the ratioke2/Gmempis dimensionless. Look up a Table of Physical Constants anddetermine the value of this ratio. What does the ratio signify?
Answer» Check that the ratio ke²/G m_em_pis dimensionless. Look up a Table of Physical Constants and determine the value of this ratio. What does the ratio signify?

Discussion

12.	A bowling ball is thrown down the alley in such a way that it slides with a speed v0 initially without rolling. What will it it's speed be when (and if) it starts pure rolling? The transition from pure sliding to pure rolling is gradual, so that both sliding and rolling takes place during this interval.
Answer» A bowling ball is thrown down the alley in such a way that it slides with a speed $v_{0}$ initially without rolling. What will it it's speed be when (and if) it starts pure rolling? The transition from pure sliding to pure rolling is gradual, so that both sliding and rolling takes place during this interval.

Discussion

13.	A small sphere of radius r1 and charge q1 is enclosed by a sphericalshell of radius r2 and charge q2. Show that if q1 is positive, chargewill necessarily flow from the sphere to the shell (when the two areconnected by a wire) no matter what the charge q2 on the shell is.
Answer» A small sphere of radius r1 and charge q1 is enclosed by a sphericalshell of radius r2 and charge q2. Show that if q1 is positive, chargewill necessarily flow from the sphere to the shell (when the two areconnected by a wire) no matter what the charge q2 on the shell is.

Discussion

14.	A particle of mass m is projected with a velocity V making an angle of 30∘ with the horizontal. The magnitude of the angular momentum of the projectile motion about the point of projection when the particle is at maximum height H is given by which of the following expression(s)?
Answer» A particle of mass $m$ is projected with a velocity $V$ making an angle of $30^{\circ}$ with the horizontal. The magnitude of the angular momentum of the projectile motion about the point of projection when the particle is at maximum height $H$ is given by which of the following expression(s)?

Discussion

15.	In an organ pipe (which may be closed or open) of 99 cm length, standing wave is set up whose equation is given by, longitudinal displacement(s) = 0.3 mm cos[(2π0.8)(z+0.01m)]cos 400t where z is measured from the top of tube in metres and t is in seconds. Take end correction = 1 cm. Choose the correct statement(s).
Answer» In an organ pipe (which may be closed or open) of 99 cm length, standing wave is set up whose equation is given by, longitudinal displacement(s) = 0.3 mm $c o s [(\frac{2 π}{0.8}) (z + 0.01 m)] c o s 400 t$ where z is measured from the top of tube in metres and t is in seconds. Take end correction = 1 cm. Choose the correct statement(s).

15.

In an organ pipe (which may be closed or open) of 99 cm length, standing wave is set up whose equation is given by, longitudinal displacement(s) = 0.3 mm cos[(2π0.8)(z+0.01m)]cos 400t where z is measured from the top of tube in metres and t is in seconds. Take end correction = 1 cm. Choose the correct statement(s).

Answer»

In an organ pipe (which may be closed or open) of 99 cm length, standing wave is set up whose equation is given by, longitudinal displacement(s) = 0.3 mm $c o s [(\frac{2 π}{0.8}) (z + 0.01 m)] c o s 400 t$ where z is measured from the top of tube in metres and t is in seconds. Take end correction = 1 cm. Choose the correct statement(s).

Discussion

16.	At magnetic poles of earth, angle of dip is
Answer» At magnetic poles of earth, angle of dip is

Discussion

17.	A block of mass 0.8 kg is placed on a rough horizontal floor having coefficient of kinetic friction, μ=0.2. Find the acceleration (in m/s2) of the block. Take g=10 m/s2
Answer» A block of mass $0.8 kg$ is placed on a rough horizontal floor having coefficient of kinetic friction, $μ = 0.2$ . Find the acceleration (in ${m/s}^{2}$ ) of the block. Take $g = 10 {m/s}^{2}$

Discussion

18.	Find the resistance of the truncated cone as shown.
Answer» Find the resistance of the truncated cone as shown.

Discussion

19.	A particle is moving in a circle of radiusconstant v. The magnitude of change in velocity inwith2TDangular displacementradian is3(1) v(2) v 2(3) v 3(4) 2v
Answer» A particle is moving in a circle of radiusconstant v. The magnitude of change in velocity inwith2TDangular displacementradian is3(1) v(2) v 2(3) v 3(4) 2v

Discussion

20.	A pump is used to deliver water at a certain rate from a given pipe. To obtain water 2 times in the same time, the power of the pump has to be made : (a) 2 times (b) 4 times (c)8 times (d)16 times
Answer» A pump is used to deliver water at a certain rate from a given pipe. To obtain water 2 times in the same time, the power of the pump has to be made : (a) 2 times (b) 4 times (c)8 times (d)16 times

Discussion

21.	Taking force, length and time to be the fundamental quantities find the dimensions of (a) density, (b) pressure, (c) momentun and (d) energy.
Answer» Taking force, length and time to be the fundamental quantities find the dimensions of (a) density, (b) pressure, (c) momentun and (d) energy.

21.

Taking force, length and time to be the fundamental quantities find the dimensions of (a) density, (b) pressure, (c) momentun and (d) energy.

Answer»

Taking force, length and time to be the fundamental quantities find the dimensions of

(a) density,

(b) pressure,

(c) momentun and

(d) energy.

Discussion

22.	The tube is open at end A. Then, absolute pressure at end B is - (Take atmospheric pressure to be 105 Pa)
Answer» The tube is open at end $A$ . Then, absolute pressure at end $B$ is - (Take atmospheric pressure to be $10^{5} Pa$ )

Discussion

23.	(a) Obtain the de Broglie wavelength of a neutron of kinetic energy 150 eV. As you have seen in Exercise 11.31, an electron beam of this energy is suitable for crystal diffraction experiments. Would a neutron beam of the same energy be equally suitable? Explain. (mn = 1.675 × 10–27 kg) (b) Obtain the de Broglie wavelength associated with thermal neutrons at room temperature (27 °C). Hence explain why a fast neutron beam needs to be thermalised with the environment before it can be used for neutron diffraction experiments.
Answer» (a) Obtain the de Broglie wavelength of a neutron of kinetic energy 150 eV. As you have seen in Exercise 11.31, an electron beam of this energy is suitable for crystal diffraction experiments. Would a neutron beam of the same energy be equally suitable? Explain. (mn = 1.675 × 10–27 kg) (b) Obtain the de Broglie wavelength associated with thermal neutrons at room temperature (27 °C). Hence explain why a fast neutron beam needs to be thermalised with the environment before it can be used for neutron diffraction experiments.

Discussion

24.	A person throws vertically n balls per second with the same velocity. He throws a ball whenever the previous one is at its highest point. The height to which the balls rise is
Answer» A person throws vertically $n$ balls per second with the same velocity. He throws a ball whenever the previous one is at its highest point. The height to which the balls rise is

Discussion

25.	A point charge q held at the centre of a circle of radius r. Points B and C are two fixed points on the circumference of the circle and A is a point outside the circle as shown. If WAB represents the work done by electric field in taking a charge q0 from A to B and WAC represents the work done from A to C, then
Answer» A point charge $q$ held at the centre of a circle of radius $r$ . Points $B$ and $C$ are two fixed points on the circumference of the circle and $A$ is a point outside the circle as shown. If $W_{A B}$ represents the work done by electric field in taking a charge $q_{0}$ from $A$ to $B$ and $W_{A C}$ represents the work done from $A$ to $C$ , then

Discussion

26.	In most stable nuclei, neutron number N and proton number Z has the relation
Answer» In most stable nuclei, neutron number $N$ and proton number $Z$ has the relation

Discussion

27.	when B is varying with time why does E become non conservative ,non electrostatic and ehow does electric field lines form closed loop
Answer» when B is varying with time why does E become non conservative ,non electrostatic and ehow does electric field lines form closed loop

Discussion

28.	Explain thermal expansion with suitable examples.
Answer» Explain thermal expansion with suitable examples.

Discussion

29.	Two objects A and B each of mass m are connected by a light inextensible string. They are restricted to move on a frictionless ring of radius R in a vertical plane (as shown in figure). The objects are released from rest at the position shown. Then, the tension in the cord just after release is
Answer» Two objects A and B each of mass m are connected by a light inextensible string. They are restricted to move on a frictionless ring of radius R in a vertical plane (as shown in figure). The objects are released from rest at the position shown. Then, the tension in the cord just after release is

29.

Two objects A and B each of mass m are connected by a light inextensible string. They are restricted to move on a frictionless ring of radius R in a vertical plane (as shown in figure). The objects are released from rest at the position shown. Then, the tension in the cord just after release is

Answer»

Two objects A and B each of mass m are connected by a light inextensible string. They are restricted to move on a frictionless ring of radius R in a vertical plane (as shown in figure). The objects are released from rest at the position shown. Then, the tension in the cord just after release is

Discussion

30.	In the given reactionzXA→z+1YA→z−1KA−4→z−1KA−4Radioactive radiations are emitted in the sequence of
Answer» In the given reaction $_{z} X^{A} \to_{z + 1} Y^{A} \to_{z - 1} K^{A - 4} \to_{z - 1} K^{A - 4}$ Radioactive radiations are emitted in the sequence of

Discussion

31.	Two capacitors of 400 μF and 600 μF are connected in parallel to a battery of 100V. Find the ratio of charge stored in 400 μF to charge stored in 600 μF.
Answer» Two capacitors of $400 μ F$ and $600 μ F$ are connected in parallel to a battery of $100 V .$ Find the ratio of charge stored in $400 μ F$ to charge stored in $600 μ F$ .

Discussion

32.	A rod of length 4m is rotated about an axis perpendicular to the rod and passing through a point 1 m from one of its end as shown in figure. The rod has a uniform mass density and has a total mass of 10 kg. What will be its moment of Inertia about this axis?
Answer» A rod of length 4m is rotated about an axis perpendicular to the rod and passing through a point 1 m from one of its end as shown in figure. The rod has a uniform mass density and has a total mass of 10 kg. What will be its moment of Inertia about this axis?

Discussion

33.	A 700 g solid cube having an edge of length 10 cm float in water. How much volume of the cube is outside the water? (Density of water = 1000 kg m−3)
Answer» A $700 g$ solid cube having an edge of length $10 c m$ float in water. How much volume of the cube is outside the water? (Density of water = $1000 k g$ $m^{- 3}$ )

Discussion

34.	In orbit, objects inside a spacecraft feel weightless
Answer» In orbit, objects inside a spacecraft feel weightless

Discussion

35.	A spherical conductor of radius 3 m carries a charge of 2 μC on its surface. What is the value of electric field just outside the surface of the sphere?
Answer» A spherical conductor of radius $3 m$ carries a charge of $2 μ C$ on its surface. What is the value of electric field just outside the surface of the sphere?

Discussion

36.	Two tall buildings are 40 m apart. With what speed a ball must be thrown horizontally from a window 145 m above the ground in one building, so that it will enter a window 22.5 m above the ground in the other ? (Take g=10 m/s2)
Answer» Two tall buildings are $40 m$ apart. With what speed a ball must be thrown horizontally from a window $145 m$ above the ground in one building, so that it will enter a window $22.5 m$ above the ground in the other ? (Take $g = 10 m / s^{2}$ )

Discussion

37.	Since friction slows us down, we can run very fast if friction is eliminated. Do you agree? Give reasons.
Answer» Since friction slows us down, we can run very fast if friction is eliminated. Do you agree? Give reasons.

Discussion

38.	A solenoid of length 50 cm with 600 turns is connected to a cell and current through the solenoid is 20πA. Find magnetic field inside the solenoid (in central region). Assume solenoid is ideal
Answer» A solenoid of length $50 c m$ with $600 t u r n s$ is connected to a cell and current through the solenoid is $\frac{20}{π} A$ . Find magnetic field inside the solenoid (in central region). Assume solenoid is ideal

Discussion

39.	The number of turns in the coil of an a.c. generator is 5000 and the area of the coil is 0.25 m2. The coil is rotated at the rate of 100 cycle per second in a magnetic field of 0.2 T. The peak value of the emf generated is nearly
Answer» The number of turns in the coil of an a.c. generator is $5000$ and the area of the coil is $0.25 m^{2}$ . The coil is rotated at the rate of $100 cycle per second$ in a magnetic field of $0.2 T .$ The peak value of the emf generated is nearly

Discussion

40.	A non-conducting spherical ball of radius R contains a spherically symmetric charge with volume charge density ρ=krn, where r is the distance from the center of the ball and n is a constant. The value of n such that the electric field inside the ball is directly proportional to square of distance from the centre is
Answer» A non-conducting spherical ball of radius $R$ contains a spherically symmetric charge with volume charge density $ρ = k r^{n}$ , where $r$ is the distance from the center of the ball and $n$ is a constant. The value of $n$ such that the electric field inside the ball is directly proportional to square of distance from the centre is

Discussion

41.	A block of mass m is placed on another block of mass M.The coefficient of friction between two blocks is u1 and that between the block of mass M and horizontal surface is up. What maximum horizontal force can be applied to the lower block so that the two blocks move without separation
Answer» A block of mass m is placed on another block of mass M.The coefficient of friction between two blocks is u1 and that between the block of mass M and horizontal surface is up. What maximum horizontal force can be applied to the lower block so that the two blocks move without separation

Discussion

42.	8.A homogenous rod XY of length L mass M is pivoted at the centre C such that it can rotate freely in vertical plane . Initially the rod is in horizontal posIiton. A blob of same mass M as that of rod , falls vertically with speed V and sticks rod midway between C and Y . If rod rotated with angular speed 'w' what will be angular speed in terms of V and L ?
Answer» 8.A homogenous rod XY of length L mass M is pivoted at the centre C such that it can rotate freely in vertical plane . Initially the rod is in horizontal posIiton. A blob of same mass M as that of rod , falls vertically with speed V and sticks rod midway between C and Y . If rod rotated with angular speed 'w' what will be angular speed in terms of V and L ?

Discussion

43.	Two identical spheres A and B lie on a smooth horizontal circular groove at opposite ends of a diameter. At time t = 0, A is projected along the groove and at time t = T, it impinges on sphere B. If e is the coefficient of restitution, the second impact will occur after a time equal to
Answer» Two identical spheres A and B lie on a smooth horizontal circular groove at opposite ends of a diameter. At time t = 0, A is projected along the groove and at time t = T, it impinges on sphere B. If e is the coefficient of restitution, the second impact will occur after a time equal to

Discussion

44.	An over head line having surge impedance of 400Ω is connected in series with an underground cable having a surge impedance of 50Ω. If a surge of 100 kV travels from the line towards the cable junction. The coefficient of refraction of voltage at the junction of cable and overload line is ____.0.222
Answer» An over head line having surge impedance of $400 Ω$ is connected in series with an underground cable having a surge impedance of $50 Ω$ . If a surge of 100 kV travels from the line towards the cable junction. The coefficient of refraction of voltage at the junction of cable and overload line is ____. 0.222

Discussion

45.	The frequency of the whistle of an engine appears to be (56)th of the original frequency , when it passes a stationary observer. If the speed of sound in air is 350 m/s, then the speed of the engine is:[Assume, medium is stationary and the original frequency of the whistle is measured when the source and observer are at rest]
Answer» The frequency of the whistle of an engine appears to be ${(\frac{5}{6})}^{t h}$ of the original frequency , when it passes a stationary observer. If the speed of sound in air is $350 m/s$ , then the speed of the engine is: [Assume, medium is stationary and the original frequency of the whistle is measured when the source and observer are at rest]

Discussion

46.	Draw electric field Vs r graph from -infinity to infinity for a point on the axis of a dipole
Answer» Draw electric field Vs r graph from -infinity to infinity for a point on the axis of a dipole

Discussion

47.	Convergence of concave mirror can be decreased by dipping in 1. Water 2.oil 3.none Please explain
Answer» Convergence of concave mirror can be decreased by dipping in 1. Water 2.oil 3.none Please explain

Discussion

48.	To maintain a rotor at a uniform angular speed of 200 rad/s, an engine needs to transmit a torque of 180 N m. What is the power required by the engine? (Note: Uniform angular velocity in the absence of friction implies zero torque. In practice, applied torque is needed to counter frictional torque). Assume that the engine is 100% efficient.
Answer» To maintain a rotor at a uniform angular speed of 200 rad/s, an engine needs to transmit a torque of 180 N m. What is the power required by the engine? (Note: Uniform angular velocity in the absence of friction implies zero torque. In practice, applied torque is needed to counter frictional torque). Assume that the engine is 100% efficient.

Discussion

49.	A particle is dropped from the top of the tower of height H. Distance travelled by the particle in last second is 35 m. Find the height of the tower.[Take g=10 m/s2]
Answer» A particle is dropped from the top of the tower of height $H$ . Distance travelled by the particle in last second is $35 m$ . Find the height of the tower. [Take $g = 10 {m/s}^{2}$ ]

Discussion

50.	Collimator in the Davisson and Germer experiment set up causes the electron beam to become -
Answer» Collimator in the Davisson and Germer experiment set up causes the electron beam to become -

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

12. Two bodies of masses m1 and m2 are initially at rest at infinite distance apart.They are then allowed to move towards each other under mutual gravitational attraction.Their relative velocity of approach at a separation distance r between them.

An inductance of 200πmH, a capacitance of 10−3πF and a resistance of 10 Ω are connected in series with an a.c. source 220 V, 50 Hz. The phase angle of the circuit for the current and voltage source is

A body at the end of a spring executes S.H.M. with a period t1, while the corresponding period for another spring is t2. If the period of oscillation with the two springs in series is T, then

The nature of electromagnetic waves Z = is

Two racing cars of masses m1 and m2 are moving in circles of radii r1 and r2 respectively. Their speeds are such that each makes a complete circle at the same time t. The ratio of the angular speeds of the first to the second car is 1) r1 :\:r2 2) m1 : m2 3) 1 : 1 4) m1m2 : r1r2

31 Calculate the standard free energy change for the reaction 4 NH3 (g) + 5O2 (g) 4NO (g) + 6 H2O (l) Given that the free energy change for the formation of NH3 (g), NO (g) and H2O (l) are -16.8, +86.7 and -273.2 kJ/mole respectively. Predict the feasibility of the reaction.

A radioactive nucleus of mass M emits a photon offrequency v and the nucleus recoils. The recoil\lbrack AIPMT (Prelims)-2011\rbrack energy will be:(1) hv(2) Mc2- hvh2v2(3)2Mc(4) Zero

Forces of 5 N , 12N, 13N are in equilibrium.if sin 23 degree is equal to 5 by 13 then the angle between the 5N and 13N force is

A particle moves along x-axis such that the directionof its motion is always towards the origin. If x, v anda respectively represent position, velocity andacceleration of the particle, then choose the correctoption.(1) xv = 0 (2) xv > 0(3) xa < 0 (4) xv < 0

Check that the ratioke2/Gmempis dimensionless. Look up a Table of Physical Constants anddetermine the value of this ratio. What does the ratio signify?

A small sphere of radius r1 and charge q1 is enclosed by a sphericalshell of radius r2 and charge q2. Show that if q1 is positive, chargewill necessarily flow from the sphere to the shell (when the two areconnected by a wire) no matter what the charge q2 on the shell is.

A particle of mass m is projected with a velocity V making an angle of 30∘ with the horizontal. The magnitude of the angular momentum of the projectile motion about the point of projection when the particle is at maximum height H is given by which of the following expression(s)?

At magnetic poles of earth, angle of dip is

A block of mass 0.8 kg is placed on a rough horizontal floor having coefficient of kinetic friction, μ=0.2. Find the acceleration (in m/s2) of the block. Take g=10 m/s2

Find the resistance of the truncated cone as shown.

A particle is moving in a circle of radiusconstant v. The magnitude of change in velocity inwith2TDangular displacementradian is3(1) v(2) v 2(3) v 3(4) 2v

A pump is used to deliver water at a certain rate from a given pipe. To obtain water 2 times in the same time, the power of the pump has to be made : (a) 2 times (b) 4 times (c)8 times (d)16 times

Taking force, length and time to be the fundamental quantities find the dimensions of (a) density, (b) pressure, (c) momentun and (d) energy.

The tube is open at end A. Then, absolute pressure at end B is - (Take atmospheric pressure to be 105 Pa)

A person throws vertically n balls per second with the same velocity. He throws a ball whenever the previous one is at its highest point. The height to which the balls rise is

In most stable nuclei, neutron number N and proton number Z has the relation

when B is varying with time why does E become non conservative ,non electrostatic and ehow does electric field lines form closed loop

Explain thermal expansion with suitable examples.

Two objects A and B each of mass m are connected by a light inextensible string. They are restricted to move on a frictionless ring of radius R in a vertical plane (as shown in figure). The objects are released from rest at the position shown. Then, the tension in the cord just after release is

In the given reactionzXA→z+1YA→z−1KA−4→z−1KA−4Radioactive radiations are emitted in the sequence of

Two capacitors of 400 μF and 600 μF are connected in parallel to a battery of 100V. Find the ratio of charge stored in 400 μF to charge stored in 600 μF.

A rod of length 4m is rotated about an axis perpendicular to the rod and passing through a point 1 m from one of its end as shown in figure. The rod has a uniform mass density and has a total mass of 10 kg. What will be its moment of Inertia about this axis?

A 700 g solid cube having an edge of length 10 cm float in water. How much volume of the cube is outside the water? (Density of water = 1000 kg m−3)

In orbit, objects inside a spacecraft feel weightless

A spherical conductor of radius 3 m carries a charge of 2 μC on its surface. What is the value of electric field just outside the surface of the sphere?

Two tall buildings are 40 m apart. With what speed a ball must be thrown horizontally from a window 145 m above the ground in one building, so that it will enter a window 22.5 m above the ground in the other ? (Take g=10 m/s2)

Since friction slows us down, we can run very fast if friction is eliminated. Do you agree? Give reasons.

A solenoid of length 50 cm with 600 turns is connected to a cell and current through the solenoid is 20πA. Find magnetic field inside the solenoid (in central region). Assume solenoid is ideal

The number of turns in the coil of an a.c. generator is 5000 and the area of the coil is 0.25 m2. The coil is rotated at the rate of 100 cycle per second in a magnetic field of 0.2 T. The peak value of the emf generated is nearly

A block of mass m is placed on another block of mass M.The coefficient of friction between two blocks is u1 and that between the block of mass M and horizontal surface is up. What maximum horizontal force can be applied to the lower block so that the two blocks move without separation

Two identical spheres A and B lie on a smooth horizontal circular groove at opposite ends of a diameter. At time t = 0, A is projected along the groove and at time t = T, it impinges on sphere B. If e is the coefficient of restitution, the second impact will occur after a time equal to

Draw electric field Vs r graph from -infinity to infinity for a point on the axis of a dipole

Convergence of concave mirror can be decreased by dipping in 1. Water 2.oil 3.none Please explain

A particle is dropped from the top of the tower of height H. Distance travelled by the particle in last second is 35 m. Find the height of the tower.[Take g=10 m/s2]

Collimator in the Davisson and Germer experiment set up causes the electron beam to become -