50278 + Interview Questions in Physics

1.	A plot of volume (V) versus temperature (T) for a gas at constant pressure is a straight line passing through the origin. The plots at different values of pressure are shown in the figure. Which of the following order of pressures is correct for this gas?
Answer» A plot of volume $(V)$ versus temperature $(T)$ for a gas at constant pressure is a straight line passing through the origin. The plots at different values of pressure are shown in the figure. Which of the following order of pressures is correct for this gas?

Discussion

2.	A thin disc of radius b=2a has concentric hole of radius ‘a’ in it (see figure). It carries uniform surface charge ‘σ’ on it. If the electric field on its axis at height ‘h’ (h<<a) from its centre is given as ‘Ch’, then value of ‘C’ is:
Answer» A thin disc of radius $b = 2 a$ has concentric hole of radius ‘ $a$ ’ in it (see figure). It carries uniform surface charge ‘ $σ$ ’ on it. If the electric field on its axis at height ‘ $h$ ’ $(h << a)$ from its centre is given as ‘ $C h$ ’, then value of ‘ $C$ ’ is:

Discussion

3.	A particle of mass m attached to a string of length l is describing circular motion on a smooth plane inclined at an angle α with the horizontal. For the particle to complete the loop, its velocity at the lowest point should exceed
Answer» A particle of mass $m$ attached to a string of length $l$ is describing circular motion on a smooth plane inclined at an angle $α$ with the horizontal. For the particle to complete the loop, its velocity at the lowest point should exceed

Discussion

4.	A body of mass ‘m’ is accelerated uniformly from rest to a speed ‘V’ in a time ‘T’. The instantaneous power delivered to the body as a function time is given by
Answer» A body of mass ‘m’ is accelerated uniformly from rest to a speed ‘V’ in a time ‘T’. The instantaneous power delivered to the body as a function time is given by

Discussion

5.	Magnetic field of magnitude B0 exist in the region above the line as shown in figure. A charged particle of mass m and charge q moving at speed 'u' enters magnetic field region. Find time interval for which particle remains in magnetic field.
Answer» Magnetic field of magnitude $B_{0}$ exist in the region above the line as shown in figure. A charged particle of mass m and charge q moving at speed 'u' enters magnetic field region. Find time interval for which particle remains in magnetic field.

Discussion

6.	Two similar springs P and Q have spring constants KP and KQ, such that KP>KQ. They are stretched, first by the same amount (case a), then by the same force (case b). The work done by the springs WPand WQ are related as, in case (a) and case (b), respectively :
Answer» Two similar springs P and Q have spring constants $K_{P}$ and $K_{Q}$ , such that $K_{P} > K_{Q}$ . They are stretched, first by the same amount (case a), then by the same force (case b). The work done by the springs W_Pand W_Q are related as, in case (a) and case (b), respectively :

Discussion

7.	A uniform string of length l is fixed at both ends such that tension T is produced in it. The string is excited to vibrate with maximum displacement amplitude a0. The maximum kinetic energy of the string for its first overtone is
Answer» A uniform string of length l is fixed at both ends such that tension T is produced in it. The string is excited to vibrate with maximum displacement amplitude $a_{0}$ . The maximum kinetic energy of the string for its first overtone is

7.

A uniform string of length l is fixed at both ends such that tension T is produced in it. The string is excited to vibrate with maximum displacement amplitude a0. The maximum kinetic energy of the string for its first overtone is

Answer»

A uniform string of length l is fixed at both ends such that tension T is produced in it. The string is excited to vibrate with maximum displacement amplitude $a_{0}$ .

The maximum kinetic energy of the string for its first overtone is

Discussion

8.	In the circuit shown, a potential difference of 60V is applied across AB. The potential difference between the point M and N is
Answer» In the circuit shown, a potential difference of 60V is applied across AB. The potential difference between the point M and N is

8.

In the circuit shown, a potential difference of 60V is applied across AB. The potential difference between the point M and N is

Answer»

In the circuit shown, a potential difference of 60V is applied across AB. The potential difference between the point M and N is

Discussion

9.	Four identical charges are placed at the four vertices of a square lying in YZ plane with origin at the centre of a square. A fifth charge is moved along X axis. The variation of potential energy (U) along X axis is correctly represented by
Answer» Four identical charges are placed at the four vertices of a square lying in YZ plane with origin at the centre of a square. A fifth charge is moved along X axis. The variation of potential energy (U) along X axis is correctly represented by

Discussion

10.	A particle of mass m is at rest at the origin at time t=0. It is subjected to a force F(t)=F0e−bt in the x-direction .Its speed v(t) is depicted by which of the following curves ?
Answer» A particle of mass $m$ is at rest at the origin at time $t = 0$ . It is subjected to a force $F (t) = F_{0} e^{- b t}$ in the x-direction .Its speed $v (t)$ is depicted by which of the following curves ?

Discussion

11.	In YDSE experiment distance on screen from central bright fringe where intensity is 25% of maximum intensity is
Answer» In YDSE experiment distance on screen from central bright fringe where intensity is $25 %$ of maximum intensity is

Discussion

12.	The momentum p of a particle changes with time according to the relation, dpdt=10+2tN. If the momentum is zero at t = 0 s. What will the momentum (inNs) at t=10 s.
Answer» The momentum p of a particle changes with time according to the relation, $\frac{d p}{d t} = 10 + 2 t N$ . If the momentum is zero at t = 0 s. What will the momentum $(i n \frac{N}{s})$ at t=10 s.

Discussion

13.	Sir what is meant by dimensional analysis and its limitations . Can I have a answer in easy language. Not understood any of the dimensional analysis ?
Answer» Sir what is meant by dimensional analysis and its limitations . Can I have a answer in easy language. Not understood any of the dimensional analysis ?

Discussion

14.	A body of mass m moving with a velocity v in the x-direction collides with a body of mass M moving with a velocity V in the y-direction. They stick together during the collision. Choose the correct statement/statements.
Answer» A body of mass $m$ moving with a velocity $v$ in the x-direction collides with a body of mass $M$ moving with a velocity $V$ in the y-direction. They stick together during the collision. Choose the correct statement/statements.

Discussion

15.	How to determine whether the torque of a force is zero?
Answer» How to determine whether the torque of a force is zero?

Discussion

16.	A tensile force of magnitude 200 kN is applied on the prismatic steel rod having radius 10 mm and length 1 m. If Young's modulus of steel is 2×1011 N/m2, find out the elongation in steel rod.
Answer» A tensile force of magnitude $200 kN$ is applied on the prismatic steel rod having radius $10 mm$ and length $1 m$ . If Young's modulus of steel is $2 \times 10^{11} {N/m}^{2}$ , find out the elongation in steel rod.

Discussion

17.	A particle executes SHM. The graph between velocity and acceleration is
Answer» A particle executes SHM. The graph between velocity and acceleration is

Discussion

18.	One end of a spring of force constant k is fixed to a vertical wall and the other to a block of mass m resting on a smooth horizontal surface. There is another wall at a distance x0 from the block. The spring is then compressed by 2x0 and released. The time taken to strike the wall is
Answer» One end of a spring of force constant k is fixed to a vertical wall and the other to a block of mass m resting on a smooth horizontal surface. There is another wall at a distance $x_{0}$ from the block. The spring is then compressed by $2 x_{0}$ and released. The time taken to strike the wall is

Discussion

19.	A water pump pump out 2400 kg of water per minute if water is coming out with a velocity of 3 metre per second what is the power of the pump??? my way of thinking: F=∆p/∆t F=v ∆m/∆t we get force as 120 N now considering the displacement as 3 metre from velocity we get work done and hence the power as 360 watt why I am incorrect????
Answer» A water pump pump out 2400 kg of water per minute if water is coming out with a velocity of 3 metre per second what is the power of the pump??? my way of thinking: F=∆p/∆t F=v ∆m/∆t we get force as 120 N now considering the displacement as 3 metre from velocity we get work done and hence the power as 360 watt why I am incorrect????

Discussion

20.	A particle of mass 10g is executing simple harmonic motion with an amplitude of 0.5m and periodic time of π5s. The maximum value of the force acting on the particle is
Answer» A particle of mass 10g is executing simple harmonic motion with an amplitude of 0.5m and periodic time of $\frac{π}{5} s$ . The maximum value of the force acting on the particle is

Discussion

21.	A thin lens of focal length f and its aperture diameter d, forms a real image of intensity I. Now the central part of the aperture of diameter (d2) is blocked by an opaque paper. The focal length and image intensity would change to
Answer» A thin lens of focal length $f$ and its aperture diameter $d$ , forms a real image of intensity $I$ . Now the central part of the aperture of diameter $(\frac{d}{2})$ is blocked by an opaque paper. The focal length and image intensity would change to

Discussion

22.	A wire 4 m long and 0.3 mm diameter is stretched by a force of 100N. If the extension in the wire is 0.3 mm, calculate the potential energy stored in the wire.
Answer» A wire 4 m long and 0.3 mm diameter is stretched by a force of 100N. If the extension in the wire is 0.3 mm, calculate the potential energy stored in the wire.

Discussion

23.	The angular velocity is given by
Answer» The angular velocity is given by

Discussion

24.	A ball of mass 500 g is initially at rest at the bottom most point of a smooth vertical circular track of radius 10 m. For looping a loop, the minimum kinetic energy the ball should have at the bottommost point on the track is
Answer» A ball of mass $500 g$ is initially at rest at the bottom most point of a smooth vertical circular track of radius $10 m$ . For looping a loop, the minimum kinetic energy the ball should have at the bottommost point on the track is

Discussion

25.	A spring is stretched by 0.20 m, when a mass of 0.50 kg is suspended. When a mass of 0.25 kg is suspended, then its period of oscillation will be ( g = 10 m/s2 )
Answer» A spring is stretched by 0.20 m, when a mass of 0.50 kg is suspended. When a mass of 0.25 kg is suspended, then its period of oscillation will be ( g = 10 m/ $s^{2}$ )

Discussion

26.	Two tuning forks when sounded together produced 4 beats/sec. The frequency of one fork is 256. The number of beats heard increases when the fork of frequency 256 is loaded with wax. The frequency of the other fork is [CPMT 1976; MP PMT 1993]
Answer» Two tuning forks when sounded together produced 4 beats/sec. The frequency of one fork is 256. The number of beats heard increases when the fork of frequency 256 is loaded with wax. The frequency of the other fork is [CPMT 1976; MP PMT 1993]

26.

Two tuning forks when sounded together produced 4 beats/sec. The frequency of one fork is 256. The number of beats heard increases when the fork of frequency 256 is loaded with wax. The frequency of the other fork is [CPMT 1976; MP PMT 1993]

Answer»

Two tuning forks when sounded together produced 4 beats/sec. The frequency of one fork is 256. The number of beats heard increases when the fork of frequency 256 is loaded with wax. The frequency of the other fork is

[CPMT 1976; MP PMT 1993]

Discussion

27.	An electric motor creates a tension of 4500 newton in a hoisting cable and reels it in at the rate of 2 m/sec. What is the power of electric motor
Answer» An electric motor creates a tension of 4500 newton in a hoisting cable and reels it in at the rate of 2 m/sec. What is the power of electric motor

Discussion

28.	Two samples A and B of the same gas have equal volumes and pressuresa. THe gas in sample A is expanded isotherm ally to duble ist volume and the gas in B is expanded adiabat ically to double its volume. If the work done by the gas is the same for the two cases, show that γ satisfies the equation 1−21−γ = (γ−1) In2
Answer» Two samples A and B of the same gas have equal volumes and pressuresa. THe gas in sample A is expanded isotherm ally to duble ist volume and the gas in B is expanded adiabat ically to double its volume. If the work done by the gas is the same for the two cases, show that $γ$ satisfies the equation $1 - 2^{1 - γ}$ = $(γ - 1)$ In2

Discussion

29.	A capacitor of capacitance 10 μF is connected to a battery of emf 2 V. It is found that it takes 50 ms for the charge on the capacitor to become 12.6 μC. Find the resistance of the circuit.
Answer» A capacitor of capacitance 10 $μ F$ is connected to a battery of emf 2 V. It is found that it takes 50 ms for the charge on the capacitor to become 12.6 $μ C$ . Find the resistance of the circuit.

Discussion

30.	A load of 10 kg is suspended by a metal wire 3 m long and hvaing a cross- sectional area 4mm2. Find (a) the stress (b) the strain and (c) the elongation. Young modulus of the metal is 2.0 ×1011Nm−2.
Answer» A load of 10 kg is suspended by a metal wire 3 m long and hvaing a cross- sectional area $4 m m^{2}$ . Find (a) the stress (b) the strain and (c) the elongation. Young modulus of the metal is 2.0 $\times 10^{11} N m^{- 2}$ .

Discussion

31.	On a large tray of mass M, an ice cube of mass m, edge L is kept. If the ice melts completely, how will the centre of mass of the system be affected? Assume gravity is present.
Answer» On a large tray of mass M, an ice cube of mass m, edge L is kept. If the ice melts completely, how will the centre of mass of the system be affected? Assume gravity is present.

Discussion

32.	Seven homo genous bricks , each of length L , are arranged as shown below. Each brick is displaced with respect to the one in contact by L10. Find X coordinate of the centre of mass relative to the origin shown
Answer» Seven homo genous bricks , each of length $L$ , are arranged as shown below. Each brick is displaced with respect to the one in contact by $\frac{L}{10}$ . Find $X$ coordinate of the centre of mass relative to the origin shown

32.

Seven homo genous bricks , each of length L , are arranged as shown below. Each brick is displaced with respect to the one in contact by L10. Find X coordinate of the centre of mass relative to the origin shown

Answer»

Seven homo genous bricks , each of length $L$ , are arranged as shown below. Each brick is displaced with respect to the one in contact by $\frac{L}{10}$ . Find $X$ coordinate of the centre of mass relative to the origin shown

Discussion

33.	If (x+1)2(x3+x)=Ax+(Bx+c)x2+1 , the sin−1 A+tan−1 B+sec−1 C=
Answer» If $\frac{(x + 1)^{2}}{(x^{3} + x)} = \frac{A}{x} + \frac{(B x + c)}{x^{2} + 1}$ , the $s i n^{- 1} A + t a n^{- 1} B + s e c^{- 1} C =$

Discussion

34.	A projectile is fired from the surface of the earth with a velocity of 5 ms−1 and angle θ with the horizontal. Another projectile fired from another planet with a velocity of 3 ms−1 at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet (in ms−2) is (Given g=9.8 ms−2)
Answer» A projectile is fired from the surface of the earth with a velocity of $5 {ms}^{- 1}$ and angle $θ$ with the horizontal. Another projectile fired from another planet with a velocity of $3 {ms}^{- 1}$ at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet (in ${ms}^{- 2}$ ) is (Given $g = 9.8 {ms}^{- 2}$ )

34.

A projectile is fired from the surface of the earth with a velocity of 5 ms−1 and angle θ with the horizontal. Another projectile fired from another planet with a velocity of 3 ms−1 at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet (in ms−2) is (Given g=9.8 ms−2)

Answer»

A projectile is fired from the surface of the earth with a velocity of $5 {ms}^{- 1}$ and angle $θ$ with the horizontal. Another projectile fired from another planet with a velocity of $3 {ms}^{- 1}$ at the same angle follows a trajectory which is identical with the trajectory of the projectile fired from the earth. The value of the acceleration due to gravity on the planet (in ${ms}^{- 2}$ ) is

(Given $g = 9.8 {ms}^{- 2}$ )

Discussion

35.	Statement I: An isolated neutron can spontaneously convert itself into a proton, while an isolated proton can't spontaneously convert itself into a neutron. Statement II: Any process, in which the mass of the products is higher than the mass of the reactants, is not favorable.
Answer» Statement I: An isolated neutron can spontaneously convert itself into a proton, while an isolated proton can't spontaneously convert itself into a neutron. Statement II: Any process, in which the mass of the products is higher than the mass of the reactants, is not favorable.

Discussion

36.	A frictionless wire AB is fixed on a sphere of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is
Answer» A frictionless wire AB is fixed on a sphere of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is

Discussion

37.	In which of the following systems will the radius of the first orbit be minimum
Answer» In which of the following systems will the radius of the first orbit be minimum

Discussion

38.	Three charges -q1, + q2 and -q3 are placed as shown in the figure. The x-component of the force on -q1 is proportional to
Answer» Three charges -q₁, + q₂ and -q₃ are placed as shown in the figure. The x-component of the force on -q₁ is proportional to

Discussion

39.	Which of the following velocity time graphs shows a realistic situation for a body in motion?
Answer» Which of the following velocity time graphs shows a realistic situation for a body in motion?

Discussion

40.	A block of mass 2kg hangs from the rim of a wheel of radius 0.5m. On releasing from rest the block falls through 5m height in 2s.The moment of inertia of the wheel will be
Answer» A block of mass 2kg hangs from the rim of a wheel of radius 0.5m. On releasing from rest the block falls through 5m height in 2s.The moment of inertia of the wheel will be

40.

A block of mass 2kg hangs from the rim of a wheel of radius 0.5m. On releasing from rest the block falls through 5m height in 2s.The moment of inertia of the wheel will be

Answer»

A block of mass 2kg hangs from the rim of a wheel of radius 0.5m. On releasing from rest the block falls through 5m height in 2s.The moment of inertia of the wheel will be

Discussion

41.	A thick uniform rubber rope of density 1.5gcm−3 and Young’s modulus 5×106Nm−7 has a length of 8m. When hung from the ceiling of a room, the increase in length of the rope due to its own weight will be
Answer» A thick uniform rubber rope of density $1.5 g c m^{- 3}$ and Young’s modulus $5 \times 10^{6} N m^{- 7}$ has a length of 8m. When hung from the ceiling of a room, the increase in length of the rope due to its own weight will be

Discussion

42.	If power developed across 6Ω resistor is equal to the power developed across 24Ω resistor. The value of R is
Answer» If power developed across $6 Ω$ resistor is equal to the power developed across $24 Ω$ resistor. The value of R is

Discussion

43.	Five identical rods are joined as shown in figure. Point A and C are maintained at temperature 120∘ C and 20∘ C respectively. The temperature of junction B will be
Answer» Five identical rods are joined as shown in figure. Point A and C are maintained at temperature $120^{\circ}$ C and $20^{\circ}$ C respectively. The temperature of junction B will be

Discussion

44.	In a series CR circuit shown in figure, the applied voltage is 10 V and the voltage across capacitor is found to be 8V. Then the voltage across R, and the phase difference between current and the applied voltage will respectively be
Answer» In a series CR circuit shown in figure, the applied voltage is 10 V and the voltage across capacitor is found to be 8V. Then the voltage across R, and the phase difference between current and the applied voltage will respectively be

Discussion

45.	By sucking through a straw, a student can reduce the pressure in his lungs to 750 mm of Hg (density = 13.6g/cm3). Using the straw, he can drink water from a glass upto a maximum depth of
Answer» By sucking through a straw, a student can reduce the pressure in his lungs to 750 mm of Hg (density = $13.6 g / c m^{3}$ ). Using the straw, he can drink water from a glass upto a maximum depth of

Discussion

46.	An incompressible liquid flows through a horizontal tube as shown in figure, then the velocity V of the fluid as given in the figure is
Answer» An incompressible liquid flows through a horizontal tube as shown in figure, then the velocity $V$ of the fluid as given in the figure is

Discussion

47.	The heat generated in circuit q=I2 Rt where I is current, R is resistance and t is time. If the percentage error in measuring I, R and t are 2%, 1 respectively, then the maximum error in measuring heat will be
Answer» The heat generated in circuit $q = I^{2}$ Rt where I is current, R is resistance and t is time. If the percentage error in measuring I, R and t are $2 %, 1$ respectively, then the maximum error in measuring heat will be

Discussion

48.	The position of a particle moving along x-axis varies with time t as x=4t−t2+1. If the time interval(s) during which the particle is moving along positive x-direction is 0<t<u. The value of u (in s) is
Answer» The position of a particle moving along x-axis varies with time $t$ as $x = 4 t - t^{2} + 1$ . If the time interval(s) during which the particle is moving along positive x-direction is $0 < t < u$ . The value of $u$ (in $s$ ) is

Discussion

49.	A 20 cm long string, having a mass of 1.0 g, is fixed at both ends. The tension in the string is 0.5 N. The string is set into vibrations using an external oscillator of frequency 100 Hz. What is the seperation (in cm) between the successive nodes on the string.
Answer» A $20 cm$ long string, having a mass of $1.0 g$ , is fixed at both ends. The tension in the string is $0.5 N$ . The string is set into vibrations using an external oscillator of frequency $100 Hz$ . What is the seperation (in $cm)$ between the successive nodes on the string.

Discussion

50.	In the diagram, resistance between any two junctions is R. Equivalent resistance across terminals A and B is
Answer» In the diagram, resistance between any two junctions is R. Equivalent resistance across terminals A and B is

50.

In the diagram, resistance between any two junctions is R. Equivalent resistance across terminals A and B is

Answer»

In the diagram, resistance between any two junctions is R. Equivalent resistance across terminals A and B is

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A plot of volume (V) versus temperature (T) for a gas at constant pressure is a straight line passing through the origin. The plots at different values of pressure are shown in the figure. Which of the following order of pressures is correct for this gas?

A thin disc of radius b=2a has concentric hole of radius ‘a’ in it (see figure). It carries uniform surface charge ‘σ’ on it. If the electric field on its axis at height ‘h’ (h&lt;&lt;a) from its centre is given as ‘Ch’, then value of ‘C’ is:

A particle of mass m attached to a string of length l is describing circular motion on a smooth plane inclined at an angle α with the horizontal. For the particle to complete the loop, its velocity at the lowest point should exceed

A body of mass ‘m’ is accelerated uniformly from rest to a speed ‘V’ in a time ‘T’. The instantaneous power delivered to the body as a function time is given by

Magnetic field of magnitude B0 exist in the region above the line as shown in figure. A charged particle of mass m and charge q moving at speed 'u' enters magnetic field region. Find time interval for which particle remains in magnetic field.

Two similar springs P and Q have spring constants KP and KQ, such that KP&gt;KQ. They are stretched, first by the same amount (case a), then by the same force (case b). The work done by the springs WPand WQ are related as, in case (a) and case (b), respectively :

A uniform string of length l is fixed at both ends such that tension T is produced in it. The string is excited to vibrate with maximum displacement amplitude a0. The maximum kinetic energy of the string for its first overtone is

In the circuit shown, a potential difference of 60V is applied across AB. The potential difference between the point M and N is

Four identical charges are placed at the four vertices of a square lying in YZ plane with origin at the centre of a square. A fifth charge is moved along X axis. The variation of potential energy (U) along X axis is correctly represented by

A particle of mass m is at rest at the origin at time t=0. It is subjected to a force F(t)=F0e−bt in the x-direction .Its speed v(t) is depicted by which of the following curves ?

In YDSE experiment distance on screen from central bright fringe where intensity is 25% of maximum intensity is

The momentum p of a particle changes with time according to the relation, dpdt=10+2tN. If the momentum is zero at t = 0 s. What will the momentum (inNs) at t=10 s.

Sir what is meant by dimensional analysis and its limitations . Can I have a answer in easy language. Not understood any of the dimensional analysis ?

A body of mass m moving with a velocity v in the x-direction collides with a body of mass M moving with a velocity V in the y-direction. They stick together during the collision. Choose the correct statement/statements.

How to determine whether the torque of a force is zero?

A tensile force of magnitude 200 kN is applied on the prismatic steel rod having radius 10 mm and length 1 m. If Young's modulus of steel is 2×1011 N/m2, find out the elongation in steel rod.

A particle executes SHM. The graph between velocity and acceleration is

One end of a spring of force constant k is fixed to a vertical wall and the other to a block of mass m resting on a smooth horizontal surface. There is another wall at a distance x0 from the block. The spring is then compressed by 2x0 and released. The time taken to strike the wall is

A particle of mass 10g is executing simple harmonic motion with an amplitude of 0.5m and periodic time of π5s. The maximum value of the force acting on the particle is

A thin lens of focal length f and its aperture diameter d, forms a real image of intensity I. Now the central part of the aperture of diameter (d2) is blocked by an opaque paper. The focal length and image intensity would change to

A wire 4 m long and 0.3 mm diameter is stretched by a force of 100N. If the extension in the wire is 0.3 mm, calculate the potential energy stored in the wire.

The angular velocity is given by

A ball of mass 500 g is initially at rest at the bottom most point of a smooth vertical circular track of radius 10 m. For looping a loop, the minimum kinetic energy the ball should have at the bottommost point on the track is

A spring is stretched by 0.20 m, when a mass of 0.50 kg is suspended. When a mass of 0.25 kg is suspended, then its period of oscillation will be ( g = 10 m/s2 )

Two tuning forks when sounded together produced 4 beats/sec. The frequency of one fork is 256. The number of beats heard increases when the fork of frequency 256 is loaded with wax. The frequency of the other fork is [CPMT 1976; MP PMT 1993]

An electric motor creates a tension of 4500 newton in a hoisting cable and reels it in at the rate of 2 m/sec. What is the power of electric motor

A capacitor of capacitance 10 μF is connected to a battery of emf 2 V. It is found that it takes 50 ms for the charge on the capacitor to become 12.6 μC. Find the resistance of the circuit.

A load of 10 kg is suspended by a metal wire 3 m long and hvaing a cross- sectional area 4mm2. Find (a) the stress (b) the strain and (c) the elongation. Young modulus of the metal is 2.0 ×1011Nm−2.

On a large tray of mass M, an ice cube of mass m, edge L is kept. If the ice melts completely, how will the centre of mass of the system be affected? Assume gravity is present.

Seven homo genous bricks , each of length L , are arranged as shown below. Each brick is displaced with respect to the one in contact by L10. Find X coordinate of the centre of mass relative to the origin shown

If (x+1)2(x3+x)=Ax+(Bx+c)x2+1 , the sin−1 A+tan−1 B+sec−1 C=

Statement I: An isolated neutron can spontaneously convert itself into a proton, while an isolated proton can't spontaneously convert itself into a neutron. Statement II: Any process, in which the mass of the products is higher than the mass of the reactants, is not favorable.

A frictionless wire AB is fixed on a sphere of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is

In which of the following systems will the radius of the first orbit be minimum

Three charges -q1, + q2 and -q3 are placed as shown in the figure. The x-component of the force on -q1 is proportional to

Which of the following velocity time graphs shows a realistic situation for a body in motion?

A block of mass 2kg hangs from the rim of a wheel of radius 0.5m. On releasing from rest the block falls through 5m height in 2s.The moment of inertia of the wheel will be

A thick uniform rubber rope of density 1.5gcm−3 and Young’s modulus 5×106Nm−7 has a length of 8m. When hung from the ceiling of a room, the increase in length of the rope due to its own weight will be

If power developed across 6Ω resistor is equal to the power developed across 24Ω resistor. The value of R is

Five identical rods are joined as shown in figure. Point A and C are maintained at temperature 120∘ C and 20∘ C respectively. The temperature of junction B will be

In a series CR circuit shown in figure, the applied voltage is 10 V and the voltage across capacitor is found to be 8V. Then the voltage across R, and the phase difference between current and the applied voltage will respectively be

By sucking through a straw, a student can reduce the pressure in his lungs to 750 mm of Hg (density = 13.6g/cm3). Using the straw, he can drink water from a glass upto a maximum depth of

An incompressible liquid flows through a horizontal tube as shown in figure, then the velocity V of the fluid as given in the figure is

The heat generated in circuit q=I2 Rt where I is current, R is resistance and t is time. If the percentage error in measuring I, R and t are 2%, 1 respectively, then the maximum error in measuring heat will be

The position of a particle moving along x-axis varies with time t as x=4t−t2+1. If the time interval(s) during which the particle is moving along positive x-direction is 0&lt;t&lt;u. The value of u (in s) is

A 20 cm long string, having a mass of 1.0 g, is fixed at both ends. The tension in the string is 0.5 N. The string is set into vibrations using an external oscillator of frequency 100 Hz. What is the seperation (in cm) between the successive nodes on the string.

In the diagram, resistance between any two junctions is R. Equivalent resistance across terminals A and B is

A thin disc of radius b=2a has concentric hole of radius ‘a’ in it (see figure). It carries uniform surface charge ‘σ’ on it. If the electric field on its axis at height ‘h’ (h<<a) from its centre is given as ‘Ch’, then value of ‘C’ is:

Two similar springs P and Q have spring constants KP and KQ, such that KP>KQ. They are stretched, first by the same amount (case a), then by the same force (case b). The work done by the springs WPand WQ are related as, in case (a) and case (b), respectively :

The position of a particle moving along x-axis varies with time t as x=4t−t2+1. If the time interval(s) during which the particle is moving along positive x-direction is 0<t<u. The value of u (in s) is