50278 + Interview Questions in Physics

1.	In figure shown, all surfaces are smooth. A force F=2mg is acting on block A. If R is contact force between A and B and a is acceleration of B, then
Answer» In figure shown, all surfaces are smooth. A force $F = 2 m g$ is acting on block $A$ . If $R$ is contact force between $A$ and $B$ and $a$ is acceleration of $B$ , then

Discussion

2.	A man standing on a road has to hold his umbrella at 60o with the vertical to keep the rain away. He throws the umbrella and starts running at 10√3 km/h. He finds that raindrops are hitting his head vertically. Find the speed of raindrops with respect to the ground.
Answer» A man standing on a road has to hold his umbrella at $60^{o}$ with the vertical to keep the rain away. He throws the umbrella and starts running at $10 \sqrt{3} k m / h$ . He finds that raindrops are hitting his head vertically. Find the speed of raindrops with respect to the ground.

Discussion

3.	One mole of diatomic gas at 300 K is compressed adiabatically to one-fourth of its volume. If γ=1.5, the work done on gas will be
Answer» One $mole$ of diatomic gas at $300 K$ is compressed adiabatically to one-fourth of its volume. If $γ = 1.5$ , the work done on gas will be

Discussion

4.	A particle of mass 2 kg is moving in a circular path of constant radius 1 m such that its centripetal acceleration ac is varying with time t as ac=100t2. The power delivered to the particle by the force acting on it in 5 sec is
Answer» A particle of mass $2 kg$ is moving in a circular path of constant radius $1 m$ such that its centripetal acceleration $a_{c}$ is varying with time $t$ as $a_{c} = 100 t^{2}$ . The power delivered to the particle by the force acting on it in $5 sec$ is

Discussion

5.	A boy throw a ball upwards with velocity v0 = 20 m/s . The wind imparts a horizontal acceleration of 4 m/s2 to the left. The angle θ at which the ball must be thrown so that the ball returns to the boy's hand is ( g = 10m/s2 )
Answer» A boy throw a ball upwards with velocity $v_{0}$ = 20 m/s . The wind imparts a horizontal acceleration of 4 m/ $s^{2}$ to the left. The angle $θ$ at which the ball must be thrown so that the ball returns to the boy's hand is ( g = 10m/ $s^{2}$ )

5.

A boy throw a ball upwards with velocity v0 = 20 m/s . The wind imparts a horizontal acceleration of 4 m/s2 to the left. The angle θ at which the ball must be thrown so that the ball returns to the boy's hand is ( g = 10m/s2 )

Answer»

A boy throw a ball upwards with velocity $v_{0}$ = 20 m/s . The wind imparts a horizontal acceleration of 4 m/ $s^{2}$ to the left.

The angle $θ$ at which the ball must be thrown so that the ball returns to the boy's hand is ( g = 10m/ $s^{2}$ )

Discussion

6.	The internal energy of a gas is given by U=1.5 pv. It expands from 100 cm3 to 200 cm3 against a constant pressure of 1.0×105 Pa. Calculate the heat absorbed by the gas in the process.
Answer» The internal energy of a gas is given by $U = 1.5 pv$ . It expands from 100 $c m^{3}$ to 200 $c m^{3}$ against a constant pressure of $1.0 \times 10^{5} Pa$ . Calculate the heat absorbed by the gas in the process.

Discussion

7.	A particle of mass m moving eastwards with a speed v collides with another particle of same mass moving northwards with same speed v. The two particles coalesces on collision. Then, the new particle of mass 2m will move with velocity:
Answer» A particle of mass $m$ moving eastwards with a speed $v$ collides with another particle of same mass moving northwards with same speed $v$ . The two particles coalesces on collision. Then, the new particle of mass $2 m$ will move with velocity:

Discussion

8.	A ball rolls off the edge of a horizontal table top 4m high. If it strikes the floor at a point 5 m horizontally away from the edge of the table, what was its speed at the instant it left the table. ___
Answer» A ball rolls off the edge of a horizontal table top 4m high. If it strikes the floor at a point 5 m horizontally away from the edge of the table, what was its speed at the instant it left the table. ___

Discussion

9.	Let →a and →b are two vectors, such that \|→a\|=3 and \|→b\|=2. If →a−→b is unit vector, then the acute angle between →a and →b is ______
Answer» Let $\to a$ and $\to b$ are two vectors, such that $\| \to a \| = 3$ and $\| \to b \| = 2$ . If $\to a - \to b$ is unit vector, then the acute angle between $\to a$ and $\to b$ is ______

Discussion

10.	In a hydroelectric power station, 1000 kg of water is allowed to drop through a height of 100 m in 1 s. If the conservation of potential energy to electric energy is 60%, calculate the power output.
Answer» In a hydroelectric power station, 1000 kg of water is allowed to drop through a height of 100 m in 1 s. If the conservation of potential energy to electric energy is $60 %$ , calculate the power output.

Discussion

11.	A mass m = 2.0 kg is attached to a spring having a force constant k = 290 N/m as in the figure. The mass is displaced from its equilibrium position and released. Its frequency of oscillation (in Hz) is approximately:
Answer» A mass m = 2.0 kg is attached to a spring having a force constant k = 290 N/m as in the figure. The mass is displaced from its equilibrium position and released. Its frequency of oscillation (in Hz) is approximately:

Discussion

12.	A ball is thrown up from the earth by a person and then caught by him on its return. When the ball falls towards the earth, the ratio of kinetic energies gained by the ball (KB) and the earth (KE) is
Answer» A ball is thrown up from the earth by a person and then caught by him on its return. When the ball falls towards the earth, the ratio of kinetic energies gained by the ball $(K_{B})$ and the earth $(K_{E})$ is

Discussion

13.	A particle moves in a circle of radius 1 cm at a speed given by v=2t, where v is in cm/s and t is in seconds. Total acceleration of the particle at t=1 second is 2√n cm/s2 Find value of n.
Answer» A particle moves in a circle of radius $1 c m$ at a speed given by $v = 2 t$ , where $v$ is in $c m / s$ and $t$ is in seconds. Total acceleration of the particle at $t = 1$ second is $2 \sqrt{n} c m / s^{2}$ Find value of $n$ .

Discussion

14.	For a diatomic molecule, according to kinetic theory of gases
Answer» For a diatomic molecule, according to kinetic theory of gases

Discussion

15.	What is the percentage change in length of 1m iron rod if the temperature change by 100∘C (α=2×10−5/∘)C
Answer» What is the percentage change in length of 1m iron rod if the temperature change by $100^{\circ}$ C ( $α = 2 \times 10^{- 5} /^{\circ}$ )C

Discussion

16.	With what speed should a body be thrown upwards so that the distances traversed in 5th second and 6th second are equal?
Answer» With what speed should a body be thrown upwards so that the distances traversed in $5^{t h}$ second and $6^{t h}$ second are equal?

Discussion

17.	A body hangs from a spring balance supported from the roof of the elevator, the balance reads 50 N when the elevator has an upward acceleration of 2.5 m/s2. What is the true weight of the body? (Take g = 10 m/s2)
Answer» A body hangs from a spring balance supported from the roof of the elevator, the balance reads $50 N$ when the elevator has an upward acceleration of $2.5 {m/s}^{2}$ . What is the true weight of the body? $($ Take $g$ = $10 {m/s}^{2})$

Discussion

18.	An isosceles triangle is cut out of a square sheet with given dimensions as shown in figure. Find the distance of centre of mass of system from the x axis. Consider the material to be of uniform density.
Answer» An isosceles triangle is cut out of a square sheet with given dimensions as shown in figure. Find the distance of centre of mass of system from the $x$ axis. Consider the material to be of uniform density.

Discussion

19.	Voltmeters V1 and V2 are connected in series across a d.c. line. V1 reads 80 V and has a per volt resistance of 200Ω, V2 has a total resistance of 32 kΩ. The line voltage is
Answer» Voltmeters $V_{1}$ and $V_{2}$ are connected in series across a d.c. line. $V_{1}$ reads 80 V and has a per volt resistance of $200 Ω$ , $V_{2}$ has a total resistance of $32 k Ω$ . The line voltage is

Discussion

20.	An electric line of force in the xy plane is given by equation x2+y2=1. A particle with unit positive charge, initially at rest at the point x = 1, y = 0 in the xy plane
Answer» An electric line of force in the xy plane is given by equation $x^{2} + y^{2} = 1$ . A particle with unit positive charge, initially at rest at the point x = 1, y = 0 in the xy plane

Discussion

21.	The earth takes 24 h to rotate once about its axis. How much time does the sun take to shift by 1º when viewed from the earth?
Answer» The earth takes 24 h to rotate once about its axis. How much time does the sun take to shift by 1º when viewed from the earth?

Discussion

22.	The angle turned by a body undergoing circular motion depends on time as θ=θ0+θ1t+2θ2t2. Then the angular acceleration of the body is
Answer» The angle turned by a body undergoing circular motion depends on time as $θ = θ_{0} + θ_{1} t + 2 θ_{2} t^{2}$ . Then the angular acceleration of the body is

Discussion

23.	A particle is thrown up with velocity 20 m/s. Find the time when velocity is 10 m/s. [Take g=10 m/s2]
Answer» A particle is thrown up with velocity $20 m/s$ . Find the time when velocity is $10 m/s$ . [Take $g = 10 {m/s}^{2}$ ]

Discussion

24.	Two vectors acting in the opposite directions have a resultant of 10 units. If they act at right angles to each other, then the resultant is 50 units. Calculate the magnitude of two vectors.
Answer» Two vectors acting in the opposite directions have a resultant of 10 units. If they act at right angles to each other, then the resultant is 50 units. Calculate the magnitude of two vectors.

Discussion

25.	a parachutist flying in an aerolane jumps whanit is at a height 3km above the ground.he opens his parachute when he is above ground .describe his motion
Answer» a parachutist flying in an aerolane jumps whanit is at a height 3km above the ground.he opens his parachute when he is above ground .describe his motion

Discussion

26.	Two circular discs of moment of inertia 0.4 kg-m2 and 0.6 kg-m2 are rotating about their own axis (vertical axis passing through geometric centre) at the rate of 200 rpm and 50 rpm both in clockwise direction. If both are gently brought in contact to rotate about same axis, the angular speed of the combination is
Answer» Two circular discs of moment of inertia $0.4 {kg-m}^{2}$ and $0.6 {kg-m}^{2}$ are rotating about their own axis (vertical axis passing through geometric centre) at the rate of $200 rpm$ and $50 rpm$ both in clockwise direction. If both are gently brought in contact to rotate about same axis, the angular speed of the combination is

Discussion

27.	In the figure shown, a source of sound of frequency 510 Hz moves with constant velocity vs=20m/s in the direction shown. The wind is blowing at a constant velocity vw=20m/s towards an observer who is at rest at point B. Find the frequency (in Hz) detected by the observer corresponding to the sound emitted by the source at initial position A. (speed of sound relative to air = 330 m/s)
Answer» In the figure shown, a source of sound of frequency $510$ Hz moves with constant velocity $v_{s} = 20 m/s$ in the direction shown. The wind is blowing at a constant velocity $v_{w} = 20 m/s$ towards an observer who is at rest at point B. Find the frequency (in Hz) detected by the observer corresponding to the sound emitted by the source at initial position A. (speed of sound relative to air = $330$ m/s)

Discussion

28.	A capacitor of capacitance 8.0 μF is connected to a battery of emf 6.0 V through a resistance of 24 Ω. Find the current in the circuit (a) just after the connections are made and (b) one time constant after the connections are made.
Answer» A capacitor of capacitance 8.0 $μ F$ is connected to a battery of emf 6.0 V through a resistance of 24 $Ω$ . Find the current in the circuit (a) just after the connections are made and (b) one time constant after the connections are made.

Discussion

29.	A ball is dropped on a floor from a height of 2.0 m. After the collision it rises up to height of 1.5 m. Assume that 40 % of the mechanical energy lost goes as thermal energy into the ball. Calculate the rise in the temperature of the ball in the collision. Heat capacity of the ball is 800 J K−1
Answer» A ball is dropped on a floor from a height of 2.0 m. After the collision it rises up to height of 1.5 m. Assume that 40 % of the mechanical energy lost goes as thermal energy into the ball. Calculate the rise in the temperature of the ball in the collision. Heat capacity of the ball is 800 J $K^{- 1}$

Discussion

30.	A glass flask is filled up to a mark with 50 cc of mercury at 18o C. If the flask and contents are heated to 38o C, how much mercury will be above the mark? ( for glass is 9×10−6/o C and coefficient of real expansion of mercury is 180×10−6/o C)
Answer» A glass flask is filled up to a mark with 50 cc of mercury at $18^{o} C$ . If the flask and contents are heated to $38^{o} C$ , how much mercury will be above the mark? ( for glass is $9 \times 10^{- 6} /^{o} C$ and coefficient of real expansion of mercury is $180 \times 10^{- 6} /^{o} C$ )

Discussion

31.	The figure shows a network of currents. The magnitude of current is shown here. The current i will be
Answer» The figure shows a network of currents. The magnitude of current is shown here. The current i will be

Discussion

32.	The average speed of an ideal gas molecule at 27 ∘C is 0.30 m/s. The average speed at 927 ∘C will be:-
Answer» The average speed of an ideal gas molecule at $27^{\circ} C$ is $0.30 m/s$ . The average speed at $927^{\circ} C$ will be:-

Discussion

33.	A shall at rest at the origin explodes into three fragments of masses 1 kg, 2 kg and m kg. The 1 kg and 2 kg pieces fly off with speeds of 12ms−1 along the x-axis and 8 ms−1 along the y-axis respectively. If the m kg piece flies off with a speed of 40 ms−1 , the total mass of the shell must be
Answer» A shall at rest at the origin explodes into three fragments of masses 1 kg, 2 kg and m kg. The 1 kg and 2 kg pieces fly off with speeds of $12 m s^{- 1}$ along the x-axis and 8 $m s^{- 1}$ along the y-axis respectively. If the m kg piece flies off with a speed of 40 $m s^{- 1}$ , the total mass of the shell must be

Discussion

34.	If germanium is doped with arsenic, what kind of semiconductor will be formed?
Answer» If germanium is doped with arsenic, what kind of semiconductor will be formed?

Discussion

35.	The bob of a simple pendulum has a mass m and it is executing simple harmonic motion of amplitude A and period T. it collides with a body of mass m0 placed at the equilibrium position which sticks to the bob. The time period of the oscillation of the combined masses will be
Answer» The bob of a simple pendulum has a mass m and it is executing simple harmonic motion of amplitude A and period T. it collides with a body of mass $m_{0}$ placed at the equilibrium position which sticks to the bob. The time period of the oscillation of the combined masses will be

35.

The bob of a simple pendulum has a mass m and it is executing simple harmonic motion of amplitude A and period T. it collides with a body of mass m0 placed at the equilibrium position which sticks to the bob. The time period of the oscillation of the combined masses will be

Answer»

The bob of a simple pendulum has a mass m and it is executing simple harmonic motion of amplitude A and period T. it collides with a body of mass $m_{0}$ placed at the equilibrium position which sticks to the bob. The time period of the oscillation of the combined masses will be

Discussion

36.	An electron in an atom Undergoes transition in such a way that its kinetic energy changes from x to x4, the change in potential energy will be
Answer» An electron in an atom Undergoes transition in such a way that its kinetic energy changes from x to $\frac{x}{4}$ , the change in potential energy will be

Discussion

37.	A gas cylinder has walls that can bear a maximum pressure of 1.0×106 Pa. It contains a gas at 8.0×105 Pa and 300 K. The cylinder is steadily heated. Neglecting any change in the volume, calculate the temperature at which the cylinder will break~
Answer» A gas cylinder has walls that can bear a maximum pressure of $1.0 \times 10^{6}$ Pa. It contains a gas at $8.0 \times 10^{5}$ Pa and 300 K. The cylinder is steadily heated. Neglecting any change in the volume, calculate the temperature at which the cylinder will break~

Discussion

38.	An inductor L=1100π, a capacitor C=1500π F and a resistance, R = 3Ω is connected in series with an AC voltage source as shown in the figure. The voltage of the AC source is given as V = 10 cos(100πt) volt. The potential difference between A and B is
Answer» An inductor $L = \frac{1}{100 π}$ , a capacitor $C = \frac{1}{500 π}$ F and a resistance, R = $3 Ω$ is connected in series with an AC voltage source as shown in the figure. The voltage of the AC source is given as V = 10 cos(100 $π$ t) volt. The potential difference between A and B is

38.

An inductor L=1100π, a capacitor C=1500π F and a resistance, R = 3Ω is connected in series with an AC voltage source as shown in the figure. The voltage of the AC source is given as V = 10 cos(100πt) volt. The potential difference between A and B is

Answer»

An inductor $L = \frac{1}{100 π}$ , a capacitor $C = \frac{1}{500 π}$ F and a resistance, R = $3 Ω$ is connected in series with an AC voltage source as shown in the figure. The voltage of the AC source is given as V = 10 cos(100 $π$ t) volt. The potential difference between A and B is

Discussion

39.	A man is planning to go out with his friends in a car of mass 1500 kg via roadway. The road contains a hump of radius of curvature 30 m. Each of the friends including the man weighs an average of 80 kg. A force more than 5000 N will damage the car seriously. If he plans to go at a maximum speed of 15 m/s, what is the maximum number of people that can ride in the car?
Answer» A man is planning to go out with his friends in a car of mass $1500 kg$ via roadway. The road contains a hump of radius of curvature $30 m$ . Each of the friends including the man weighs an average of $80 kg$ . A force more than $5000 N$ will damage the car seriously. If he plans to go at a maximum speed of $15 m/s$ , what is the maximum number of people that can ride in the car?

Discussion

40.	Two positive charges of equal magnitude q are placed as shown in the figure. A negative charge of magnitude Q is placed at the centre of line joining them. The value of Q for the whole system to be in equilibrium.
Answer» Two positive charges of equal magnitude q are placed as shown in the figure. A negative charge of magnitude Q is placed at the centre of line joining them. The value of Q for the whole system to be in equilibrium.

40.

Two positive charges of equal magnitude q are placed as shown in the figure. A negative charge of magnitude Q is placed at the centre of line joining them. The value of Q for the whole system to be in equilibrium.

Answer»

Two positive charges of equal magnitude q are placed as shown in the figure. A negative charge of magnitude Q is placed at the centre of line joining them. The value of Q for the whole system to be in equilibrium.

Discussion

41.	Block A of mass m is performing SHM of amplitude a. Another block B of mass m is gently placed on A when it passes through mean position and B sticks to A. Find the amplitude of new S.H.M.
Answer» Block A of mass m is performing SHM of amplitude a. Another block B of mass m is gently placed on A when it passes through mean position and B sticks to A. Find the amplitude of new S.H.M.

Discussion

42.	An elongation of 0.4% in a wire of cross section area 10−6 m2 causes a restoring force of 80 N. Then, the young's modulus of wire is___(N/m2).
Answer» An elongation of 0.4% in a wire of cross section area $10^{- 6} m^{2}$ causes a restoring force of 80 N. Then, the young's modulus of wire is___ $(N / m^{2})$ .

Discussion

43.	Magnitude of acceleration of the two blocks is : (Radius of pulley is 1 m)
Answer» Magnitude of acceleration of the two blocks is : (Radius of pulley is $1 m$ )

Discussion

44.	The momentum p of a particle changes with time according to the relation: dpdt=(10+2t) N. If the momentum is zero at t=0 s. What will the momentum in Ns 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 in $N s$ at $t = 10 s$

Discussion

45.	A block of mass 2kg hangs on 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 on 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

45.

A block of mass 2kg hangs on 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 on 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

46.	Find the second derivative of the following function: y=e9x+15
Answer» Find the second derivative of the following function: $y = e^{9 x + 15}$

Discussion

47.	What is the value of k as used in Coulomb's law?
Answer» What is the value of k as used in Coulomb's law?

Discussion

48.	The ratio of distances covered by a freely falling body (starting from rest) during the 1st,2nd,3rd second of its motion is: [Take g=10 m/s2]
Answer» The ratio of distances covered by a freely falling body (starting from rest) during the $1^{st}, 2^{nd}, 3^{rd}$ second of its motion is: [Take $g = 10 {m/s}^{2}$ ]

Discussion

49.	When an L–R combination is connected in series with 12V – 50 Hz supply, a current of 0.5A flows through the combination. The current differs in phase from applied voltage by π3 rad. Then resistance is
Answer» When an L–R combination is connected in series with 12V – 50 Hz supply, a current of 0.5A flows through the combination. The current differs in phase from applied voltage by $\frac{π}{3}$ rad. Then resistance is

Discussion

50.	A string 1.5 m long is made of steel of density 8400 kg/m3 and Y=9×1011 N/m2, wire is maintained at tension which produces strain of 2.1×10−2 in string, the fundamental frequency of transverse of string is _____. (String is clamped at both ends)
Answer» A string $1.5 m$ long is made of steel of density $8400 k g / m^{3}$ and $Y = 9 \times 10^{11} N / m^{2}$ , wire is maintained at tension which produces strain of $2.1 \times 10^{- 2}$ in string, the fundamental frequency of transverse of string is _____. (String is clamped at both ends)

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

In figure shown, all surfaces are smooth. A force F=2mg is acting on block A. If R is contact force between A and B and a is acceleration of B, then

A man standing on a road has to hold his umbrella at 60o with the vertical to keep the rain away. He throws the umbrella and starts running at 10√3 km/h. He finds that raindrops are hitting his head vertically. Find the speed of raindrops with respect to the ground.

One mole of diatomic gas at 300 K is compressed adiabatically to one-fourth of its volume. If γ=1.5, the work done on gas will be

A particle of mass 2 kg is moving in a circular path of constant radius 1 m such that its centripetal acceleration ac is varying with time t as ac=100t2. The power delivered to the particle by the force acting on it in 5 sec is

A boy throw a ball upwards with velocity v0 = 20 m/s . The wind imparts a horizontal acceleration of 4 m/s2 to the left. The angle θ at which the ball must be thrown so that the ball returns to the boy's hand is ( g = 10m/s2 )

The internal energy of a gas is given by U=1.5 pv. It expands from 100 cm3 to 200 cm3 against a constant pressure of 1.0×105 Pa. Calculate the heat absorbed by the gas in the process.

A particle of mass m moving eastwards with a speed v collides with another particle of same mass moving northwards with same speed v. The two particles coalesces on collision. Then, the new particle of mass 2m will move with velocity:

A ball rolls off the edge of a horizontal table top 4m high. If it strikes the floor at a point 5 m horizontally away from the edge of the table, what was its speed at the instant it left the table. ___

Let →a and →b are two vectors, such that |→a|=3 and |→b|=2. If →a−→b is unit vector, then the acute angle between →a and →b is ______

In a hydroelectric power station, 1000 kg of water is allowed to drop through a height of 100 m in 1 s. If the conservation of potential energy to electric energy is 60%, calculate the power output.

A mass m = 2.0 kg is attached to a spring having a force constant k = 290 N/m as in the figure. The mass is displaced from its equilibrium position and released. Its frequency of oscillation (in Hz) is approximately:

A ball is thrown up from the earth by a person and then caught by him on its return. When the ball falls towards the earth, the ratio of kinetic energies gained by the ball (KB) and the earth (KE) is

A particle moves in a circle of radius 1 cm at a speed given by v=2t, where v is in cm/s and t is in seconds. Total acceleration of the particle at t=1 second is 2√n cm/s2 Find value of n.

For a diatomic molecule, according to kinetic theory of gases

What is the percentage change in length of 1m iron rod if the temperature change by 100∘C (α=2×10−5/∘)C

With what speed should a body be thrown upwards so that the distances traversed in 5th second and 6th second are equal?

A body hangs from a spring balance supported from the roof of the elevator, the balance reads 50 N when the elevator has an upward acceleration of 2.5 m/s2. What is the true weight of the body? (Take g = 10 m/s2)

An isosceles triangle is cut out of a square sheet with given dimensions as shown in figure. Find the distance of centre of mass of system from the x axis. Consider the material to be of uniform density.

Voltmeters V1 and V2 are connected in series across a d.c. line. V1 reads 80 V and has a per volt resistance of 200Ω, V2 has a total resistance of 32 kΩ. The line voltage is

An electric line of force in the xy plane is given by equation x2+y2=1. A particle with unit positive charge, initially at rest at the point x = 1, y = 0 in the xy plane

The earth takes 24 h to rotate once about its axis. How much time does the sun take to shift by 1º when viewed from the earth?

The angle turned by a body undergoing circular motion depends on time as θ=θ0+θ1t+2θ2t2. Then the angular acceleration of the body is

A particle is thrown up with velocity 20 m/s. Find the time when velocity is 10 m/s. [Take g=10 m/s2]

Two vectors acting in the opposite directions have a resultant of 10 units. If they act at right angles to each other, then the resultant is 50 units. Calculate the magnitude of two vectors.

a parachutist flying in an aerolane jumps whanit is at a height 3km above the ground.he opens his parachute when he is above ground .describe his motion

A capacitor of capacitance 8.0 μF is connected to a battery of emf 6.0 V through a resistance of 24 Ω. Find the current in the circuit (a) just after the connections are made and (b) one time constant after the connections are made.

A ball is dropped on a floor from a height of 2.0 m. After the collision it rises up to height of 1.5 m. Assume that 40 % of the mechanical energy lost goes as thermal energy into the ball. Calculate the rise in the temperature of the ball in the collision. Heat capacity of the ball is 800 J K−1

A glass flask is filled up to a mark with 50 cc of mercury at 18o C. If the flask and contents are heated to 38o C, how much mercury will be above the mark? ( for glass is 9×10−6/o C and coefficient of real expansion of mercury is 180×10−6/o C)

The figure shows a network of currents. The magnitude of current is shown here. The current i will be

The average speed of an ideal gas molecule at 27 ∘C is 0.30 m/s. The average speed at 927 ∘C will be:-

If germanium is doped with arsenic, what kind of semiconductor will be formed?

The bob of a simple pendulum has a mass m and it is executing simple harmonic motion of amplitude A and period T. it collides with a body of mass m0 placed at the equilibrium position which sticks to the bob. The time period of the oscillation of the combined masses will be

An electron in an atom Undergoes transition in such a way that its kinetic energy changes from x to x4, the change in potential energy will be

A gas cylinder has walls that can bear a maximum pressure of 1.0×106 Pa. It contains a gas at 8.0×105 Pa and 300 K. The cylinder is steadily heated. Neglecting any change in the volume, calculate the temperature at which the cylinder will break~

An inductor L=1100π, a capacitor C=1500π F and a resistance, R = 3Ω is connected in series with an AC voltage source as shown in the figure. The voltage of the AC source is given as V = 10 cos(100πt) volt. The potential difference between A and B is

Two positive charges of equal magnitude q are placed as shown in the figure. A negative charge of magnitude Q is placed at the centre of line joining them. The value of Q for the whole system to be in equilibrium.

Block A of mass m is performing SHM of amplitude a. Another block B of mass m is gently placed on A when it passes through mean position and B sticks to A. Find the amplitude of new S.H.M.

An elongation of 0.4% in a wire of cross section area 10−6 m2 causes a restoring force of 80 N. Then, the young's modulus of wire is___(N/m2).

Magnitude of acceleration of the two blocks is : (Radius of pulley is 1 m)

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

A block of mass 2kg hangs on 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

Find the second derivative of the following function: y=e9x+15

What is the value of k as used in Coulomb's law?

The ratio of distances covered by a freely falling body (starting from rest) during the 1st,2nd,3rd second of its motion is: [Take g=10 m/s2]

When an L–R combination is connected in series with 12V – 50 Hz supply, a current of 0.5A flows through the combination. The current differs in phase from applied voltage by π3 rad. Then resistance is

A string 1.5 m long is made of steel of density 8400 kg/m3 and Y=9×1011 N/m2, wire is maintained at tension which produces strain of 2.1×10−2 in string, the fundamental frequency of transverse of string is _____. (String is clamped at both ends)