50278 + Interview Questions in Physics

1.	Two spheres carrying charges +6uc and+9uc separated by distance d experience a force of repulsion F.When a charge of -3uc is given to both the sphere and kept at the same distance as before the new force od repulsion is
Answer» Two spheres carrying charges +6uc and+9uc separated by distance d experience a force of repulsion F.When a charge of -3uc is given to both the sphere and kept at the same distance as before the new force od repulsion is

Discussion

2.	Two particles 'A' and 'B', move with constant velocities →v1 and →v2 respectively. At the initial moment, their position vectors are →r1 and →r2 respectively. The condition for particle 'A' and 'B' for their collision is
Answer» Two particles 'A' and 'B', move with constant velocities $_{1}$ and $_{2}$ respectively. At the initial moment, their position vectors are $_{1}$ and $_{2}$ respectively. The condition for particle 'A' and 'B' for their collision is

Discussion

3.	A uniform horizontal rod of length 0.40 m and mass 1.2 kg is supported by two identical wires as shown in figure(g=10 m/sec2), then the distance x (in cm) from left wire, where a mass of 4.8 kg should be placed on the rod, so that the same tuning fork may excite the wire on left into its fundamental vibrations and that on right into its first overtone is
Answer» A uniform horizontal rod of length 0.40 m and mass 1.2 kg is supported by two identical wires as shown in figure $(g = 10 m / s e c^{2})$ , then the distance x (in cm) from left wire, where a mass of 4.8 kg should be placed on the rod, so that the same tuning fork may excite the wire on left into its fundamental vibrations and that on right into its first overtone is

Discussion

4.	ABCD is a square where each side is a uniform wire of resistance 1Ω . A point E lies on CD such that if a uniform wire of resistance 1Ω is connected across AE and constant potential difference is applied across A and C then B and E are equipotential. Then, the ratio of lengths
Answer» ABCD is a square where each side is a uniform wire of resistance 1 $Ω$ . A point E lies on CD such that if a uniform wire of resistance 1 $Ω$ is connected across AE and constant potential difference is applied across A and C then B and E are equipotential. Then, the ratio of lengths

Discussion

5.	A 500 kg car takes a round turn of radius 50m with a speed of 36 km/hr. The centripetal force acting on the car will be
Answer» A 500 kg car takes a round turn of radius 50m with a speed of 36 km/hr. The centripetal force acting on the car will be

Discussion

6.	A light and smooth pulley is attached to the ceiling of a lift moving upward with acceleration a0=2 m/s2 as shown in the figure. Two blocks of equal masses (m=3 kg) are attached to the two ends of a massless string passing over the pulley. Find the tension in the string. (Take g=10 m/s2).
Answer» A light and smooth pulley is attached to the ceiling of a lift moving upward with acceleration $a_{0} = 2 {m/s}^{2}$ as shown in the figure. Two blocks of equal masses $(m = 3 kg)$ are attached to the two ends of a massless string passing over the pulley. Find the tension in the string. (Take $g = 10 {m/s}^{2}$ ).

Discussion

7.	A cubical block of wood of side a and density ρ floats in water of density 2ρ. The lower surface of the cube just touches the free end of a massless spring of force constant K fixed at the bottom of the vessel. The weight W put over the block so that it is completely immersed in water without wetting the weight is
Answer» A cubical block of wood of side $a$ and density $ρ$ floats in water of density $2 ρ$ . The lower surface of the cube just touches the free end of a massless spring of force constant $K$ fixed at the bottom of the vessel. The weight $W$ put over the block so that it is completely immersed in water without wetting the weight is

Discussion

8.	Find the equivalent capacitance across A and B in μf. (Write upto two digits after the decimal point.)
Answer» Find the equivalent capacitance across $A$ and $B$ in $μ f$ . (Write upto two digits after the decimal point.)

Discussion

9.	Air is pushed into a soap bubble of radius r to triple its radius. If the surface tension of the soap solution is S, then the work done in the process is
Answer» Air is pushed into a soap bubble of radius $r$ to triple its radius. If the surface tension of the soap solution is $S$ , then the work done in the process is

Discussion

10.	In the circuit shown figure switch S can be shifted to position A or Position B. Current through resistance is say i1 when switch is in position A and i2 when switch is in position B, then
Answer» In the circuit shown figure switch S can be shifted to position A or Position B. Current through resistance is say i₁ when switch is in position A and i₂ when switch is in position B, then

10.

In the circuit shown figure switch S can be shifted to position A or Position B. Current through resistance is say i1 when switch is in position A and i2 when switch is in position B, then

Answer»

In the circuit shown figure switch S can be shifted to position A or Position B. Current through resistance is say i₁ when switch is in position A and i₂ when switch is in position B, then

Discussion

11.	Water is flowing continuously from a tap having an internal diameter 8×10−3 m. The water velocity as it leaves the tap is 0.4 m/s. The diameter of the water stream at a distance 2×10−1 m below the tap is close to
Answer» Water is flowing continuously from a tap having an internal diameter $8 \times 10^{- 3} m$ . The water velocity as it leaves the tap is $0.4 m/s$ . The diameter of the water stream at a distance $2 \times 10^{- 1} m$ below the tap is close to

Discussion

12.	A mass m hangs with the help of a string wrapped around a pulley on a frictionless bearing. The pulley has mass m and radius R. Assuming the pulley to be a perfect uniform circular disc, the acceleration of the mass m, if the string does not slip on the pulley is
Answer» A mass $m$ hangs with the help of a string wrapped around a pulley on a frictionless bearing. The pulley has mass $m$ and radius $R$ . Assuming the pulley to be a perfect uniform circular disc, the acceleration of the mass $m$ , if the string does not slip on the pulley is

Discussion

13.	In the following circuit the equivalent resistance between A and B is
Answer» In the following circuit the equivalent resistance between A and B is

13.

In the following circuit the equivalent resistance between A and B is

Answer»

In the following circuit the equivalent resistance between A and B is

Discussion

14.	A particle is dropped along the axis from a height f2 on a concave mirror of focal length f as shown in the figure. The acceleration due to gravity is g . What is the maximum speed of the image.
Answer» A particle is dropped along the axis from a height $\frac{f}{2}$ on a concave mirror of focal length f as shown in the figure. The acceleration due to gravity is g . What is the maximum speed of the image.

14.

A particle is dropped along the axis from a height f2 on a concave mirror of focal length f as shown in the figure. The acceleration due to gravity is g . What is the maximum speed of the image.

Answer»

A particle is dropped along the axis from a height $\frac{f}{2}$ on a concave mirror of focal length f as shown in the figure. The acceleration due to gravity is g . What is the maximum speed of the image.

Discussion

15.	In an a.c. circuit, the instantaneous values of e.m.f. and current are E=200 sin (314 t) V and I=sin(314 t+π3) A. The average power consumed (in W) is
Answer» In an a.c. circuit, the instantaneous values of e.m.f. and current are $E = 200 s i n (314 t) V a n d I = s i n (314 t + \frac{π}{3}) A$ . The average power consumed (in $W$ ) is

Discussion

16.	The de-Broglie wavelength of an electron having 80eV of energy is nearly (leV=1.6×10−19J Mass of electron 9×10−31kg and Plank's constant 6.6×10−34Jsec)
Answer» The de-Broglie wavelength of an electron having 80eV of energy is nearly $(l e V = 1.6 \times 10^{- 19} J$ Mass of electron $9 \times 10^{- 31} k g$ and Plank's constant $6.6 \times 10^{- 34} J s e c)$

Discussion

17.	In the figure shown, find the tension T1 (in N) in the string. Assume the strings to be inextensible and pulley frictionless.
Answer» In the figure shown, find the tension $T_{1}$ (in $N$ ) in the string. Assume the strings to be inextensible and pulley frictionless.

Discussion

18.	Why is ammeter always connected in series, not in parallel?
Answer» Why is ammeter always connected in series, not in parallel?

Discussion

19.	Light from a source emitting two wavelengths λ1 and λ2 is allowed to fall on Young’s double slit apparatus after filtering one of the wavelengths. The position of interference maxima is noted. If the 4th maxima due to λ1 and the third maxima due to λ2 coincide while the other wavelength is filtered in respective cases, then λ2λ1=. (Answer upto 2 decimal digits)
Answer» Light from a source emitting two wavelengths $λ_{1}$ and $λ_{2}$ is allowed to fall on Young’s double slit apparatus after filtering one of the wavelengths. The position of interference maxima is noted. If the 4th maxima due to $λ_{1}$ and the third maxima due to $λ_{2}$ coincide while the other wavelength is filtered in respective cases, then $\frac{λ_{2}}{λ_{1}} =$ . (Answer upto 2 decimal digits)

Discussion

20.	A Carnot engine with a perfect gas acting as the working substance is operated backwards and is employed to freeze water at 0∘C. The engine is driven by a 200 W electric motor. Find the amount of water frozen per minute. The outside temperature is 20∘C. Specific latent heat of fusion (in g/min) of ice=80 cal/g and 1 J=4.2 cal.
Answer» A Carnot engine with a perfect gas acting as the working substance is operated backwards and is employed to freeze water at $0^{\circ} C$ . The engine is driven by a $200 W$ electric motor. Find the amount of water frozen per minute. The outside temperature is $20^{\circ} C$ . Specific latent heat of fusion (in $g / m i n$ ) of $ice = 80 c a l / g a n d 1 J = 4.2 c a l$ .

Discussion

21.	From a square plate of side 8 m, a circular disc of radius 2 m is removed as shown in the figure. The mass density of the square plate is 1 kg/m2. Find the center of mass of the remaining portion.
Answer» From a square plate of side $8 m$ , a circular disc of radius $2 m$ is removed as shown in the figure. The mass density of the square plate is $1 {kg/m}^{2}$ . Find the center of mass of the remaining portion.

Discussion

22.	The fundamental subatomic particle neutron was discovered by
Answer» The fundamental subatomic particle neutron was discovered by

Discussion

23.	A cylindrical piston of mass M slides smoothly inside a long cylinder closed at one end, enclosing a certain mass of gas. The cylinder is kept with its axis horizontal. If the piston is disturbed from its equilibrium position, it oscillates simple harmonically. The period of oscillation will be
Answer» A cylindrical piston of mass M slides smoothly inside a long cylinder closed at one end, enclosing a certain mass of gas. The cylinder is kept with its axis horizontal. If the piston is disturbed from its equilibrium position, it oscillates simple harmonically. The period of oscillation will be

23.

A cylindrical piston of mass M slides smoothly inside a long cylinder closed at one end, enclosing a certain mass of gas. The cylinder is kept with its axis horizontal. If the piston is disturbed from its equilibrium position, it oscillates simple harmonically. The period of oscillation will be

Answer»

A cylindrical piston of mass M slides smoothly inside a long cylinder closed at one end, enclosing a certain mass of gas. The cylinder is kept with its axis horizontal. If the piston is disturbed from its equilibrium position, it oscillates simple harmonically. The period of oscillation will be

Discussion

24.	On a certain xy plane, coordinates of Batman's position is (1,2) m and coordinates of the position of Joker is (5,4) m. Find the position vector of Joker w.r.t. Batman.
Answer» On a certain $x y$ plane, coordinates of Batman's position is $(1, 2) m$ and coordinates of the position of Joker is $(5, 4) m$ . Find the position vector of Joker w.r.t. Batman.

Discussion

25.	An aeroplane is flying horizontally with a constant velocity of 600 km/hr at an elevation of 6 km above a target(on the earth's surface).At an appropriate time, the pilot releases a ball so that it strikes the target on earth. The ball will appear to be falling
Answer» An aeroplane is flying horizontally with a constant velocity of 600 km/hr at an elevation of 6 km above a target(on the earth's surface).At an appropriate time, the pilot releases a ball so that it strikes the target on earth. The ball will appear to be falling

25.

An aeroplane is flying horizontally with a constant velocity of 600 km/hr at an elevation of 6 km above a target(on the earth's surface).At an appropriate time, the pilot releases a ball so that it strikes the target on earth. The ball will appear to be falling

Answer»

An aeroplane is flying horizontally with a constant velocity of 600 km/hr at an elevation of 6 km above a target(on the earth's surface).At an appropriate time, the pilot releases a ball so that it strikes the target on earth. The ball will appear to be falling

Discussion

26.	R.M.S velocity of an ideal gas molecules is 300 m/s at 1 atm pressure. If pressure is increased to four times, then R.M.S velocity becomes
Answer» R.M.S velocity of an ideal gas molecules is $300 m/s$ at $1 atm$ pressure. If pressure is increased to four times, then R.M.S velocity becomes

Discussion

27.	Two waves are passing simultaneously through a string. The equation of the waves are given by, y1=A1sink(x−vt) and y2=A2sink(x−vt+x0) Where the wave number k=6.28 cm−1 and x0=1.50 cm The amplitudes are A1=5.0 mm and A2=4.0 mm. Find the phase difference between the waves and the amplitude of the resulting wave.
Answer» Two waves are passing simultaneously through a string. The equation of the waves are given by, $y_{1} = A_{1} sin k (x - v t)$ and $y_{2} = A_{2} sin k (x - v t + x_{0})$ Where the wave number $k = 6.28 {cm}^{- 1}$ and $x_{0} = 1.50 cm$ The amplitudes are $A_{1} = 5.0 mm$ and $A_{2} = 4.0 mm$ . Find the phase difference between the waves and the amplitude of the resulting wave.

Discussion

28.	Two particles A and B having oposite charges 2.0×10−6C and −2.0×10−6C, are placed at a separation of 1.0 cm. (a) Write down te electric diple moment of this pair. (b) calculate the electric field at a Point on the axis of the dipole 1.0 m away from the centre. (c) Calculat the electric field at a point on the perpendicular bisector of the dipole and 1.0 m away from the centre.
Answer» Two particles A and B having oposite charges $2.0 \times 10^{- 6} C$ and $- 2.0 \times 10^{- 6} C,$ are placed at a separation of 1.0 cm. (a) Write down te electric diple moment of this pair. (b) calculate the electric field at a Point on the axis of the dipole 1.0 m away from the centre. (c) Calculat the electric field at a point on the perpendicular bisector of the dipole and 1.0 m away from the centre.

Discussion

29.	In the figure shown, the coefficient of static friction between C and ground is 0.5, coefficient of static friction between A and B is 0.25, coefficient of static friction between B and C is zero. The minimum value of force F (in Newton), to cause sliding between A and B is (Masses of A,B and C are respectively 2 kg,4 kg and 5 kg).
Answer» In the figure shown, the coefficient of static friction between $C$ and ground is $0.5$ , coefficient of static friction between $A$ and $B$ is $0.25$ , coefficient of static friction between $B$ and $C$ is zero. The minimum value of force $F$ (in Newton), to cause sliding between $A$ and $B$ is (Masses of $A, B$ and $C$ are respectively $2 k g, 4 k g$ and $5 k g$ ).

Discussion

30.	An inductor - coil of inductance 20 mH having resistance 10Ω is joined to an ideal battery of emf 5.0 V. Find the rate of change of the induced emf at t = 0, (b) t = 10 ms and (c) t = 1.0 s.
Answer» An inductor - coil of inductance 20 mH having resistance $10 Ω$ is joined to an ideal battery of emf 5.0 V. Find the rate of change of the induced emf at t = 0, (b) t = 10 ms and (c) t = 1.0 s.

Discussion

31.	A variable force acts on a 1 kg particle such that acceleration as a function of time is given by a=2t. The particle is starting from rest. Find the work done by the force on particle in first 3 seconds.
Answer» A variable force acts on a $1 kg$ particle such that acceleration as a function of time is given by $a = 2 t$ . The particle is starting from rest. Find the work done by the force on particle in first $3$ seconds.

Discussion

32.	Find the time period of small oscillations of the following systems. (a) A metre stick suspended through the 20 cm mark. (b) A ring of mass m and radius r suspended through a point on its periphery. (c) A uniform square plate of edge a suspended through a corner. (d) A uniform disc of mass m and radius r suspended through a point r2 away from the centre.
Answer» Find the time period of small oscillations of the following systems. (a) A metre stick suspended through the 20 cm mark. (b) A ring of mass m and radius r suspended through a point on its periphery. (c) A uniform square plate of edge a suspended through a corner. (d) A uniform disc of mass m and radius r suspended through a point $\frac{r}{2}$ away from the centre.

Discussion

33.	A force (3^i+4^j) N acts on a body and displaces it by (3^i+4^j) meters. The work done by the force is (Given that formula for work done is W=→F.→s)
Answer» A force $(3^i + 4^j) N$ acts on a body and displaces it by $(3^i + 4^j)$ meters. The work done by the force is (Given that formula for work done is $W = \to F . \to s)$

Discussion

34.	Which one of the following curves represents the variation of impedance (Z) with frequency f in series LCR circuit
Answer» Which one of the following curves represents the variation of impedance (Z) with frequency f in series LCR circuit

34.

Which one of the following curves represents the variation of impedance (Z) with frequency f in series LCR circuit

Answer»

Which one of the following curves represents the variation of impedance (Z) with frequency f in series LCR circuit

Discussion

35.	An electric dipole consisting of two opposite charges of magnitude 2×10−6C each, separated by a distance of 3 cm is placed in an electric field of 2×105N/C. The maximum torque on the dipole will be
Answer» An electric dipole consisting of two opposite charges of magnitude $2 \times 10^{- 6} C$ each, separated by a distance of 3 cm is placed in an electric field of $2 \times 10^{5} N / C$ . The maximum torque on the dipole will be

Discussion

36.	The wavelength of the waves arriving at P from two coherent sources S1 and S2 is 4 m, while intensity of each wave is I0. The resultant intensity at P is 2I0. Find the minimum value of S2P in metres.
Answer» The wavelength of the waves arriving at $P$ from two coherent sources $S_{1}$ and $S_{2}$ is $4 m$ , while intensity of each wave is $I_{0}$ . The resultant intensity at P is $2 I_{0}$ . Find the minimum value of $S_{2} P$ in metres.

Discussion

37.	Does photon has mass ?
Answer» Does photon has mass ?

Discussion

38.	A body has an initial velocity of 25 m/s in the negative x-direction. The following figure represents it's a - t graph. Find its displacement at t = 15s.
Answer» A body has an initial velocity of 25 m/s in the negative x-direction. The following figure represents it's a - t graph. Find its displacement at t = 15s.

38.

A body has an initial velocity of 25 m/s in the negative x-direction. The following figure represents it's a - t graph. Find its displacement at t = 15s.

Answer»

A body has an initial velocity of 25 m/s in the negative x-direction. The following figure represents it's a - t graph. Find its displacement at t = 15s.

Discussion

39.	An observer moves towards a stationary source of sound of frequency n. The apparent frequency heard by him is 2n. If the velocity of sound in air is 332 m/sec, then the velocity of the observer is
Answer» An observer moves towards a stationary source of sound of frequency n. The apparent frequency heard by him is 2n. If the velocity of sound in air is 332 m/sec, then the velocity of the observer is

Discussion

40.	A stone is projected from the ground with velocity 50 ms−1 and angle of 30∘ with horizontal. It crosses a wall after 3 s. How far the stone will fall beyond the wall? (Take g=10 ms−2)
Answer» A stone is projected from the ground with velocity $50 m s^{- 1}$ and angle of $30^{\circ}$ with horizontal. It crosses a wall after $3 s$ . How far the stone will fall beyond the wall? (Take $g = 10 m s^{- 2})$

Discussion

41.	Two particles of equal masses moving the same speed collide perfectly in-elastically. After the collision the combined mass moves with half of the speed of the individual masses. The angle between the initial momenta of individual particle is
Answer» Two particles of equal masses moving the same speed collide perfectly in-elastically. After the collision the combined mass moves with half of the speed of the individual masses. The angle between the initial momenta of individual particle is

Discussion

42.	The acceleration due to gravity at a height 2 km above the earth surface is same as that of acceleration due to gravity at depth ′d′ below the surface of earth. Then d is equal to
Answer» The acceleration due to gravity at a height $2 km$ above the earth surface is same as that of acceleration due to gravity at depth $^{'} d^{'}$ below the surface of earth. Then d is equal to

Discussion

43.	A stone is hung in air from a wire which is stretched over a sonometer. The bridges of the sonometer are Lcm apart when the wire is in unison with a tuning fork of frequency n. When the stone is completely immersed in water, the length between the bridges is lcm for re-establishing unison, the specific gravity of the material of the stone is
Answer» A stone is hung in air from a wire which is stretched over a sonometer. The bridges of the sonometer are Lcm apart when the wire is in unison with a tuning fork of frequency n. When the stone is completely immersed in water, the length between the bridges is lcm for re-establishing unison, the specific gravity of the material of the stone is

Discussion

44.	The least area of a circle circumscribing any right angled triangle of area 9π is
Answer» The least area of a circle circumscribing any right angled triangle of area $\frac{9}{π}$ is

Discussion

45.	A boat, which has a speed of 5 km/h in still water, crosses a river of width 1 km along the shortest path possible in 15 minutes. Then the velocity of the river in km/h is
Answer» A boat, which has a speed of 5 km/h in still water, crosses a river of width 1 km along the shortest path possible in 15 minutes. Then the velocity of the river in km/h is

Discussion

46.	A network of resistances is constructed with R1 and R2 as shown in the figure. The potential at the points 1, 2, 3 … n are V1,V2,V3,…Vn respectively, each having a potential k times smaller than the previous one. The ratio R1R2 is
Answer» A network of resistances is constructed with $R_{1}$ and $R_{2}$ as shown in the figure. The potential at the points 1, 2, 3 … n are $V_{1}, V_{2}, V_{3}, \dots V_{n}$ respectively, each having a potential k times smaller than the previous one. The ratio $\frac{R_{1}}{R_{2}}$ is

Discussion

47.	An electric field of 5,000,000Vm is applied across a region filled with air at atmospheric pressure. What will happen? (Dielectric strength of air is 3,000,000Vm
Answer» An electric field of $5, 000, 000 \frac{V}{m}$ is applied across a region filled with air at atmospheric pressure. What will happen? (Dielectric strength of air is $3, 000, 000 \frac{V}{m}$

Discussion

48.	A car goes on a horizontal circular road of radius R, the speed increasing at a constant rate dvdt=a. The friction coefficient between the road and the tyre is μ. Find the speed at which the car will skid.
Answer» A car goes on a horizontal circular road of radius R, the speed increasing at a constant rate $\frac{d v}{d t} = a .$ The friction coefficient between the road and the tyre is $μ .$ Find the speed at which the car will skid.

Discussion

49.	A fixed mass ‘m’ of a gas is subjected to transformation of states from K to L to M to N and back to K shown in figure. The pair of isochoric processes among the transformation of states is
Answer» A fixed mass ‘m’ of a gas is subjected to transformation of states from K to L to M to N and back to K shown in figure. The pair of isochoric processes among the transformation of states is

49.

A fixed mass ‘m’ of a gas is subjected to transformation of states from K to L to M to N and back to K shown in figure. The pair of isochoric processes among the transformation of states is

Answer»

A fixed mass ‘m’ of a gas is subjected to transformation of states from K to L to M to N and back to K shown in figure.

The pair of isochoric processes among the transformation of states is

Discussion

50.	A vessel contains a mixture of 1 mole of oxygen and two moles of nitrogen at 300 K. The ratio of the rotational kinetic energy per O2 molecule to that per N2 molecule is
Answer» A vessel contains a mixture of 1 mole of oxygen and two moles of nitrogen at $300 K$ . The ratio of the rotational kinetic energy per $O_{2}$ molecule to that per $N_{2}$ molecule is

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Two spheres carrying charges +6uc and+9uc separated by distance d experience a force of repulsion F.When a charge of -3uc is given to both the sphere and kept at the same distance as before the new force od repulsion is

Two particles 'A' and 'B', move with constant velocities →v1 and →v2 respectively. At the initial moment, their position vectors are →r1 and →r2 respectively. The condition for particle 'A' and 'B' for their collision is

ABCD is a square where each side is a uniform wire of resistance 1Ω . A point E lies on CD such that if a uniform wire of resistance 1Ω is connected across AE and constant potential difference is applied across A and C then B and E are equipotential. Then, the ratio of lengths

A 500 kg car takes a round turn of radius 50m with a speed of 36 km/hr. The centripetal force acting on the car will be

A light and smooth pulley is attached to the ceiling of a lift moving upward with acceleration a0=2 m/s2 as shown in the figure. Two blocks of equal masses (m=3 kg) are attached to the two ends of a massless string passing over the pulley. Find the tension in the string. (Take g=10 m/s2).

Find the equivalent capacitance across A and B in μf. (Write upto two digits after the decimal point.)

Air is pushed into a soap bubble of radius r to triple its radius. If the surface tension of the soap solution is S, then the work done in the process is

In the circuit shown figure switch S can be shifted to position A or Position B. Current through resistance is say i1 when switch is in position A and i2 when switch is in position B, then

Water is flowing continuously from a tap having an internal diameter 8×10−3 m. The water velocity as it leaves the tap is 0.4 m/s. The diameter of the water stream at a distance 2×10−1 m below the tap is close to

A mass m hangs with the help of a string wrapped around a pulley on a frictionless bearing. The pulley has mass m and radius R. Assuming the pulley to be a perfect uniform circular disc, the acceleration of the mass m, if the string does not slip on the pulley is

In the following circuit the equivalent resistance between A and B is

A particle is dropped along the axis from a height f2 on a concave mirror of focal length f as shown in the figure. The acceleration due to gravity is g . What is the maximum speed of the image.

In an a.c. circuit, the instantaneous values of e.m.f. and current are E=200 sin (314 t) V and I=sin(314 t+π3) A. The average power consumed (in W) is

The de-Broglie wavelength of an electron having 80eV of energy is nearly (leV=1.6×10−19J Mass of electron 9×10−31kg and Plank's constant 6.6×10−34Jsec)

In the figure shown, find the tension T1 (in N) in the string. Assume the strings to be inextensible and pulley frictionless.

Why is ammeter always connected in series, not in parallel?

From a square plate of side 8 m, a circular disc of radius 2 m is removed as shown in the figure. The mass density of the square plate is 1 kg/m2. Find the center of mass of the remaining portion.

The fundamental subatomic particle neutron was discovered by

A cylindrical piston of mass M slides smoothly inside a long cylinder closed at one end, enclosing a certain mass of gas. The cylinder is kept with its axis horizontal. If the piston is disturbed from its equilibrium position, it oscillates simple harmonically. The period of oscillation will be

On a certain xy plane, coordinates of Batman's position is (1,2) m and coordinates of the position of Joker is (5,4) m. Find the position vector of Joker w.r.t. Batman.

An aeroplane is flying horizontally with a constant velocity of 600 km/hr at an elevation of 6 km above a target(on the earth's surface).At an appropriate time, the pilot releases a ball so that it strikes the target on earth. The ball will appear to be falling

R.M.S velocity of an ideal gas molecules is 300 m/s at 1 atm pressure. If pressure is increased to four times, then R.M.S velocity becomes

An inductor - coil of inductance 20 mH having resistance 10Ω is joined to an ideal battery of emf 5.0 V. Find the rate of change of the induced emf at t = 0, (b) t = 10 ms and (c) t = 1.0 s.

A variable force acts on a 1 kg particle such that acceleration as a function of time is given by a=2t. The particle is starting from rest. Find the work done by the force on particle in first 3 seconds.

A force (3^i+4^j) N acts on a body and displaces it by (3^i+4^j) meters. The work done by the force is (Given that formula for work done is W=→F.→s)

Which one of the following curves represents the variation of impedance (Z) with frequency f in series LCR circuit

An electric dipole consisting of two opposite charges of magnitude 2×10−6C each, separated by a distance of 3 cm is placed in an electric field of 2×105N/C. The maximum torque on the dipole will be

The wavelength of the waves arriving at P from two coherent sources S1 and S2 is 4 m, while intensity of each wave is I0. The resultant intensity at P is 2I0. Find the minimum value of S2P in metres.

Does photon has mass ?

A body has an initial velocity of 25 m/s in the negative x-direction. The following figure represents it's a - t graph. Find its displacement at t = 15s.

An observer moves towards a stationary source of sound of frequency n. The apparent frequency heard by him is 2n. If the velocity of sound in air is 332 m/sec, then the velocity of the observer is

A stone is projected from the ground with velocity 50 ms−1 and angle of 30∘ with horizontal. It crosses a wall after 3 s. How far the stone will fall beyond the wall? (Take g=10 ms−2)

Two particles of equal masses moving the same speed collide perfectly in-elastically. After the collision the combined mass moves with half of the speed of the individual masses. The angle between the initial momenta of individual particle is

The acceleration due to gravity at a height 2 km above the earth surface is same as that of acceleration due to gravity at depth ′d′ below the surface of earth. Then d is equal to

The least area of a circle circumscribing any right angled triangle of area 9π is

A boat, which has a speed of 5 km/h in still water, crosses a river of width 1 km along the shortest path possible in 15 minutes. Then the velocity of the river in km/h is

A network of resistances is constructed with R1 and R2 as shown in the figure. The potential at the points 1, 2, 3 … n are V1,V2,V3,…Vn respectively, each having a potential k times smaller than the previous one. The ratio R1R2 is

An electric field of 5,000,000Vm is applied across a region filled with air at atmospheric pressure. What will happen? (Dielectric strength of air is 3,000,000Vm

A car goes on a horizontal circular road of radius R, the speed increasing at a constant rate dvdt=a. The friction coefficient between the road and the tyre is μ. Find the speed at which the car will skid.

A fixed mass ‘m’ of a gas is subjected to transformation of states from K to L to M to N and back to K shown in figure. The pair of isochoric processes among the transformation of states is

A vessel contains a mixture of 1 mole of oxygen and two moles of nitrogen at 300 K. The ratio of the rotational kinetic energy per O2 molecule to that per N2 molecule is