50278 + Interview Questions in Physics Page 59 InterviewSolution

2901.	Wedge is accelerated towards left shown in figure. θ=30∘ and all surface are smooth. The acceleration of block w.r.t wedge is (g=10m/s2)
Answer» Wedge is accelerated towards left shown in figure. $θ = 30^{\circ}$ and all surface are smooth. The acceleration of block w.r.t wedge is $(g = 10 m / s^{2})$

Discussion

2902.	Write the truth table for the circuits given in Fig. 14.48 consisting ofNOR gates only. Identify the logic operations (OR, AND, NOT) performedby the two circuits.
Answer» Write the truth table for the circuits given in Fig. 14.48 consisting ofNOR gates only. Identify the logic operations (OR, AND, NOT) performedby the two circuits.

Discussion

2903.	A swimmer can swim with velocity of 12 km/h in still water. Water flowing in a river has velocity 6 km/h. The direction with respect to the direction of flow of river water he should swim in order to reach the point on the other bank just opposite to his starting point is ∘. (Round off to the Nearest Integer) (Find the angle in degree)
Answer» A swimmer can swim with velocity of $12 km/h$ in still water. Water flowing in a river has velocity $6 km/h$ . The direction with respect to the direction of flow of river water he should swim in order to reach the point on the other bank just opposite to his starting point is $^{\circ}$ . (Round off to the Nearest Integer) (Find the angle in degree)

Discussion

2904.	A photon and an electron have equal energy E, then λphotonλelectron is proportional to
Answer» A photon and an electron have equal energy E, then $\frac{λ_{p h o t o n}}{λ_{e l e c t r o n}}$ is proportional to

Discussion

2905.	55.One mole of photon, each of frequency 2500S-1 ,would have approximately a total energy of 10erg, 1joule, 1ev, 1MeV
Answer» 55.One mole of photon, each of frequency 2500S-1 ,would have approximately a total energy of 10erg, 1joule, 1ev, 1MeV

Discussion

2906.	A capacitor 0.2μF is charged to 600V. After removing the battery, it is connected to 1μF capacitor in parallel. The voltage across 1μF will become
Answer» A capacitor $0.2 μ F$ is charged to $600 V .$ After removing the battery, it is connected to $1 μ F$ capacitor in parallel. The voltage across $1 μ F$ will become

Discussion

2907.	A resistor of resistance 2 Ω and an inductor of reactance 2 Ω are joined in series across an AC supply. The power factor is -
Answer» A resistor of resistance $2 Ω$ and an inductor of reactance $2 Ω$ are joined in series across an AC supply. The power factor is -

Discussion

2908.	A solution of urea (molar mass 56 g/mol) boils at 100.18°C at the atmospheric pressure. If Kf and Kb of water are 1.86 and 0.52 K kgmol−1 respectively, the above solution will freeze at
Answer» A solution of urea (molar mass 56 g/mol) boils at 100.18°C at the atmospheric pressure. If $K_{f}$ and $K_{b}$ of water are 1.86 and 0.52 K $k g m o l^{- 1}$ respectively, the above solution will freeze at

Discussion

2909.	Two men start from two points p and q. 8km apart and walk towards each other. They meet in 80 mins. If they walk in the same direction they meet in 2 hours. Find the speed of each man.
Answer» Two men start from two points p and q. 8km apart and walk towards each other. They meet in 80 mins. If they walk in the same direction they meet in 2 hours. Find the speed of each man.

Discussion

2910.	The side of a cube is measured by vernier caliper (10 divisions of vernier scale coincide with 9 divisions of main scale, where 1 division of main scale is 1 mm). The main scale reads 10 mm and the first division of the vernier scale coincides with the main scale. The maximum % error in measurement of volume of the cube will be
Answer» The side of a cube is measured by vernier caliper ( $10$ divisions of vernier scale coincide with $9$ divisions of main scale, where $1$ division of main scale is $1 mm$ ). The main scale reads $10 mm$ and the first division of the vernier scale coincides with the main scale. The maximum $%$ error in measurement of volume of the cube will be

Discussion

2911.	Sir I want to ask that on rubbing a glass with fur or rubbing ani two such materials, why is charge generated on it and why that charge only.
Answer» Sir I want to ask that on rubbing a glass with fur or rubbing ani two such materials, why is charge generated on it and why that charge only.

Discussion

2912.	A helium nucleus makes a full rotation in a circle of radius 0.8 m in 2 s. The value of magnetic field at the centre of the circle is
Answer» A helium nucleus makes a full rotation in a circle of radius $0.8 m$ in $2 s$ . The value of magnetic field at the centre of the circle is

Discussion

2913.	a point source of light at the surface of a sphere causes a parallel beam of light to emerge from the opposite surface of the sphere .Find the refracrive indexof the sphere
Answer» a point source of light at the surface of a sphere causes a parallel beam of light to emerge from the opposite surface of the sphere .Find the refracrive indexof the sphere

Discussion

2914.	In the above problem if the lift moves up with an acceleration equal to the acceleration due to gravity, the reading on the spring balance will be
Answer» In the above problem if the lift moves up with an acceleration equal to the acceleration due to gravity, the reading on the spring balance will be

Discussion

2915.	A current sheet →J=10^uyA/m lies on the dielectric interface x = 0 between two dielectric media with εr1=1,μr1=1 in Region -1 (x < 0) and εr2=2,μr2=2 in Region-2 (x > 0). If the magneitc field in Region-1 at x = 0+ is →H1=3^ux+30^uyA/m, the magnetic field in Region-2 at x=0+ is
Answer» A current sheet $\to J = 10 {^u}_{y} A / m$ lies on the dielectric interface x = 0 between two dielectric media with $ε_{r_{1}} = 1, μ_{r_{1}} = 1$ in Region -1 (x < 0) and $ε_{r_{2}} = 2, μ_{r_{2}} = 2$ in Region-2 (x > 0). If the magneitc field in Region-1 at x = $0^{+}$ is ${\to H}_{1} = 3 {^u}_{x} + 30 {^u}_{y} A / m,$ the magnetic field in Region-2 at $x = 0^{+}$ is

2915.

A current sheet →J=10^uyA/m lies on the dielectric interface x = 0 between two dielectric media with εr1=1,μr1=1 in Region -1 (x < 0) and εr2=2,μr2=2 in Region-2 (x > 0). If the magneitc field in Region-1 at x = 0+ is →H1=3^ux+30^uyA/m, the magnetic field in Region-2 at x=0+ is

Answer»

A current sheet

$\to J = 10 {^u}_{y} A / m$ lies on the dielectric interface x = 0 between two dielectric media with

$ε_{r_{1}} = 1, μ_{r_{1}} = 1$ in Region -1 (x < 0) and $ε_{r_{2}} = 2, μ_{r_{2}} = 2$ in Region-2 (x > 0). If the magneitc field in Region-1 at x = $0^{+}$ is ${\to H}_{1} = 3 {^u}_{x} + 30 {^u}_{y} A / m,$ the magnetic field in Region-2 at $x = 0^{+}$ is

Discussion

2916.	If a gas is taken from A to C through B, then heat absorbed by the gas is 8 J. Heat absorbed by the gas in taking it directly from A to C is
Answer» If a gas is taken from $A$ to $C$ through $B$ , then heat absorbed by the gas is $8 J$ . Heat absorbed by the gas in taking it directly from $A$ to $C$ is

Discussion

2917.	44.Two charged conducting metallic conductors are kept at a separation r and Q1 and Q2 be the charges given. Then the potential energy of the system is?(r>>a)(r>>b)
Answer» 44.Two charged conducting metallic conductors are kept at a separation r and Q1 and Q2 be the charges given. Then the potential energy of the system is?(r>>a)(r>>b)

Discussion

2918.	A ball is dropped from height h on a horizontal floor. If it loses 60% of its energy on hitting the floor, find the height to which it will rise.
Answer» A ball is dropped from height $h$ on a horizontal floor. If it loses $60 %$ of its energy on hitting the floor, find the height to which it will rise.

Discussion

2919.	Find the moment of inertia for a semicircular disc of mass m and radius r about an axis passing through its centre of mass and perpendicular to the plane of disc
Answer» Find the moment of inertia for a semicircular disc of mass m and radius r about an axis passing through its centre of mass and perpendicular to the plane of disc

Discussion

2920.	River of width d is flowing with velocity v0 as shown. A swimmer swims (with respect to water) perpendicular to the current with acceleration a=2t (where t is time) starting from rest from the origin O at t=0. The equation of trajectory of the path followed by the swimmer is
Answer» River of width $d$ is flowing with velocity $v_{0}$ as shown. A swimmer swims (with respect to water) perpendicular to the current with acceleration $a = 2 t$ (where $t$ is time) starting from rest from the origin $O$ at $t = 0$ . The equation of trajectory of the path followed by the swimmer is

Discussion

2921.	Electrical force between two charged spheres is 200 N.If we increase 10 % charge on one of the charged sphere and decrease 20 % charge in the other,then the electrical force between them for the same distance becomes
Answer» Electrical force between two charged spheres is $200 N$ .If we increase $10 %$ charge on one of the charged sphere and decrease $20 %$ charge in the other,then the electrical force between them for the same distance becomes

Discussion

2922.	If the area bounded by the curves y=\|cos−1(sinx)\|+∣∣∣π2−(cos−1cosx)∣∣∣,x- axis and π2<x<π is equal to π2k , then k is -
Answer» If the area bounded by the curves $y = \| {cos}^{- 1} (sin x) \| + ∣ ∣ ∣ \frac{π}{2} - ({cos}^{- 1} cos x) ∣ ∣ ∣, x$ - axis and $\frac{π}{2} < x < π$ is equal to $\frac{π^{2}}{k}$ , then $k$ is -

Discussion

2923.	A metallic sphere of radius r is charged so that potential at its surface is V. This charged sphere is enclosed by a concentric conducting shell of radius 2r. What is the potential of conducting shell when both are joined by a conducting wire
Answer» A metallic sphere of radius r is charged so that potential at its surface is V. This charged sphere is enclosed by a concentric conducting shell of radius 2r. What is the potential of conducting shell when both are joined by a conducting wire

Discussion

2924.	A metal bullet moving at 400 ms-1 strikes on a tree trunk and get embedded inside it. Assuming total kineticenergy is converted to heat and 50% of heat is absorbed by the bullet, the increase in its temperature willerkecttbe (specific heat capacity of metal 200 J kg K-1 and bullet not melts)
Answer» A metal bullet moving at 400 ms-1 strikes on a tree trunk and get embedded inside it. Assuming total kineticenergy is converted to heat and 50% of heat is absorbed by the bullet, the increase in its temperature willerkecttbe (specific heat capacity of metal 200 J kg K-1 and bullet not melts)

Discussion

2925.	In the circuit shown in figure, L=10H, R=5Ω,E=15V. The switch S is closed at t=0. At t=2s, the current in the circuit is:
Answer» In the circuit shown in figure, $L = 10 H, R = 5 Ω, E = 15 V$ . The switch S is closed at $t = 0$ . At $t = 2 s$ , the current in the circuit is:

Discussion

2926.	wo particles executing SHM of same amplitude of20 cm with same period along the same lineabout same equilibrium position. The maximumdistance between the two is 20 cm. Their phasedifference in radian is equal to
Answer» wo particles executing SHM of same amplitude of20 cm with same period along the same lineabout same equilibrium position. The maximumdistance between the two is 20 cm. Their phasedifference in radian is equal to

Discussion

2927.	The string of a simple pendulum is held horizontal at a height and then released. The tension in the string when the bob is at the lowest point is
Answer» The string of a simple pendulum is held horizontal at a height and then released. The tension in the string when the bob is at the lowest point is

Discussion

2928.	If ε0 and μ0 are respectively the permittivity and magnetic permeability of free space, ε and μ are the corresponding quantities in a medium. The refractive index of the medium is-
Answer» If $ε_{0} and μ_{0}$ are respectively the permittivity and magnetic permeability of free space, $ε$ and $μ$ are the corresponding quantities in a medium. The refractive index of the medium is-

Discussion

2929.	A particle of mass m is moving with speed 2v and collides with a mass 2m moving with speed v in the same direction. After collision, the first mass is stopped completely while the second one splits into two particles each of mass m, which move at angle 45∘ with respect to the original direction. The speed of each of the moving particle will be
Answer» A particle of mass $m$ is moving with speed $2 v$ and collides with a mass $2 m$ moving with speed $v$ in the same direction. After collision, the first mass is stopped completely while the second one splits into two particles each of mass $m$ , which move at angle $45^{\circ}$ with respect to the original direction. The speed of each of the moving particle will be

Discussion

2930.	During a heavy rain,hailstones of average size 1.0 cm in diameter fall with an average speed of 20 m/s.Suppose 2000 hailstones strike every square meter of a 10m×10m roof perpendicularly in one second and assume that the hailstones do not rebound.Calculate the average force exerted by the falling hailstones on the roof.Density of a hailstone is 900 kgm3.
Answer» During a heavy rain,hailstones of average size 1.0 cm in diameter fall with an average speed of 20 m/s.Suppose 2000 hailstones strike every square meter of a $10 m \times 10 m$ roof perpendicularly in one second and assume that the hailstones do not rebound.Calculate the average force exerted by the falling hailstones on the roof.Density of a hailstone is 900 $\frac{k g}{m^{3}}$ .

Discussion

2931.	A mass m moves in a circle on a smooth horizontal plane with velocity v0 at a radius R0. The mass is attached to a string which passes through a smooth hole in the plane as shown. The tension in the string is increased gradually and finally m moves in a circle of radius R02. The final value of the kinetic energy is :
Answer» A mass m moves in a circle on a smooth horizontal plane with velocity v₀ at a radius R₀. The mass is attached to a string which passes through a smooth hole in the plane as shown. The tension in the string is increased gradually and finally m moves in a circle of radius $\frac{R_{0}}{2}$ . The final value of the kinetic energy is :

2931.

A mass m moves in a circle on a smooth horizontal plane with velocity v0 at a radius R0. The mass is attached to a string which passes through a smooth hole in the plane as shown. The tension in the string is increased gradually and finally m moves in a circle of radius R02. The final value of the kinetic energy is :

Answer»

A mass m moves in a circle on a smooth horizontal plane with velocity v₀ at a radius R₀. The mass is attached to a string which passes through a smooth hole in the plane as shown.

The tension in the string is increased gradually and finally m moves in a circle of radius $\frac{R_{0}}{2}$ . The final value of the kinetic energy is :

Discussion

2932.	A motorbike is being chased by a car. The motorbike moves with the speed of 10 m/s and has acceleration of 5 m/s2. Whereas, the car has speed of 20 m/s and accelerates with 3 m/s2. If the initial separation between motorbike and car is 60 m, find the distance by which car will miss the motorbike.
Answer» A motorbike is being chased by a car. The motorbike moves with the speed of $10 m / s$ and has acceleration of $5 m / s^{2}$ . Whereas, the car has speed of $20 m / s$ and accelerates with $3 m / s^{2}$ . If the initial separation between motorbike and car is $60 m$ , find the distance by which car will miss the motorbike.

Discussion

2933.	A wheel rotation with uniform angular acceleration covers 50 revolutions in the first five seconds after the start. Find the angular acceleration and the angular velocity at the end of five seconds.
Answer» A wheel rotation with uniform angular acceleration covers 50 revolutions in the first five seconds after the start. Find the angular acceleration and the angular velocity at the end of five seconds.

Discussion

2934.	A series RLC circuit has inductance of 0.12 H, capacitance of 480 nF and resistance of 23 Ω is connected to a 230 V AC supply whose frequency can be varied. What is the source frequency for which current amplitude is maximum? Also, find the maximum value of current.
Answer» A series $R L C$ circuit has inductance of $0.12 H$ , capacitance of $480 nF$ and resistance of $23 Ω$ is connected to a $230 V$ AC supply whose frequency can be varied. What is the source frequency for which current amplitude is maximum? Also, find the maximum value of current.

Discussion

2935.	28. Two charged insulating spheres of radiusR' are kept at a distance 'd' (d> 2R). Onehas a charge + q and the other-q. The forcebetween them will be:221 q(B):0 d2(D) None of these4πε 29.Two charged conducting spheres of radius"R' are kept at a distance 'd(d > 2R). One has a charge + q and theother +q. The force between them will be:2(B) Ao 2(D) None of these4τε o d4πε 02
Answer» 28. Two charged insulating spheres of radiusR' are kept at a distance 'd' (d> 2R). Onehas a charge + q and the other-q. The forcebetween them will be:221 q(B):0 d2(D) None of these4πε 29.Two charged conducting spheres of radius"R' are kept at a distance 'd(d > 2R). One has a charge + q and theother +q. The force between them will be:2(B) Ao 2(D) None of these4τε o d4πε 02

Discussion

2936.	Coefficient of linear expansion of brass and steel rods are α1and α2 . Length of brass and steel rods are l1 and l2 respectively. If l2–l1 is maintained same at all temperatures, then find the ratio of α1 to α2.
Answer» Coefficient of linear expansion of brass and steel rods are $α_{1}$ and $α_{2}$ . Length of brass and steel rods are $l_{1}$ and $l_{2}$ respectively. If $l_{2} - l_{1}$ is maintained same at all temperatures, then find the ratio of $α_{1}$ to $α_{2}$ .

Discussion

2937.	A paticle falls from a height h upon a fixed horizontal plane and rebouns.If e is the coefficient of restitution, the total distance travelled before rebounding has stopped is ?
Answer» A paticle falls from a height h upon a fixed horizontal plane and rebouns.If e is the coefficient of restitution, the total distance travelled before rebounding has stopped is ?

Discussion

2938.	The half-life of 40K is 1.30 ×109 y. A sample of 1.00 g of pure KCI gives 160 counts s−1. Calculate the relative abundance of 40K (fraction of 40K present) in natural potassium.
Answer» The half-life of $^{40}$ K is 1.30 $\times 10^{9}$ y. A sample of 1.00 g of pure KCI gives 160 counts $s^{- 1}$ . Calculate the relative abundance of $^{40}$ K (fraction of $^{40}$ K present) in natural potassium.

Discussion

2939.	What is fulrane
Answer» What is fulrane

Discussion

2940.	A particle is moving along x−axis. Its x−coordinate versus time graph is shown. Its v−t graph will be:
Answer» A particle is moving along $x -$ axis. Its $x -$ coordinate versus time graph is shown. Its $v - t$ graph will be:

Discussion

2941.	{ A small object of mass }m, at the end of a light cord, is held horizontally at a distance }r from a fixed support as }} shown. The object is then released. What is the tension in the cord when the object is at the lowest point of its } shing?
Answer» { A small object of mass }m, at the end of a light cord, is held horizontally at a distance }r from a fixed support as }} shown. The object is then released. What is the tension in the cord when the object is at the lowest point of its } shing?

Discussion

2942.	Three light bulbs (60 W,120 V) are connected across a 120 V power source. If the resistance of each bulb does not change with current, then find out total power delivered to the three bulbs.
Answer» Three light bulbs $(60 W, 120 V)$ are connected across a $120 V$ power source. If the resistance of each bulb does not change with current, then find out total power delivered to the three bulbs.

Discussion

2943.	If several capacitors are connected both in series and parallel combination . How to identify series connection and parallel connection in a complex circuit?
Answer» If several capacitors are connected both in series and parallel combination . How to identify series connection and parallel connection in a complex circuit?

Discussion

2944.	A particle is projected vertically up with velocity v=4gR/3 from earth surface. The velocity of particle at height equal to half of maximum height reach by it
Answer» A particle is projected vertically up with velocity v=4gR/3 from earth surface. The velocity of particle at height equal to half of maximum height reach by it

Discussion

2945.	X²-x+1 alpha ki power 2009and beta powe,is,2009 solve this
Answer» X²-x+1 alpha ki power 2009and beta powe,is,2009 solve this

Discussion

2946.	A charge Q is placed at each of the two opposite corners of a square. A charge q is placed at each of the other two corners. If the resultant force on each charge q is zero, then
Answer» A charge $Q$ is placed at each of the two opposite corners of a square. A charge $q$ is placed at each of the other two corners. If the resultant force on each charge $q$ is zero, then

Discussion

2947.	Calculate screening constant sigma 3d electron of zn atom
Answer» Calculate screening constant sigma 3d electron of zn atom

Discussion

2948.	Wavelength of a 1 keV photon is 1.24×10−9m. What is the frequency of 1 MeV photon
Answer» Wavelength of a 1 keV photon is $1.24 \times 10^{- 9} m$ . What is the frequency of 1 MeV photon

Discussion

2949.	water pump driven by petrol raises water at a rate of 0.5m min-1 from a depth of 30 m. If the pump is 70%efficient, what power is developed by the engine? [Take g 9.8 ms-2]
Answer» water pump driven by petrol raises water at a rate of 0.5m min-1 from a depth of 30 m. If the pump is 70%efficient, what power is developed by the engine? [Take g 9.8 ms-2]

Discussion

2950.	A wire carrying current I has the shape as shown in the figure.Linear parts of the wire are very long and parallel to X-axis while semi-circular portion of radius R is lying in Y−Z plane. Magnetic field at point O is
Answer» A wire carrying current $I$ has the shape as shown in the figure. Linear parts of the wire are very long and parallel to $X$ -axis while semi-circular portion of radius $R$ is lying in $Y - Z$ plane. Magnetic field at point $O$ is

Discussion

Explore topic-wise InterviewSolutions in .

Wedge is accelerated towards left shown in figure. θ=30∘ and all surface are smooth. The acceleration of block w.r.t wedge is (g=10m/s2)

Write the truth table for the circuits given in Fig. 14.48 consisting ofNOR gates only. Identify the logic operations (OR, AND, NOT) performedby the two circuits.

A photon and an electron have equal energy E, then λphotonλelectron is proportional to

55.One mole of photon, each of frequency 2500S-1 ,would have approximately a total energy of 10erg, 1joule, 1ev, 1MeV

A capacitor 0.2μF is charged to 600V. After removing the battery, it is connected to 1μF capacitor in parallel. The voltage across 1μF will become

A resistor of resistance 2 Ω and an inductor of reactance 2 Ω are joined in series across an AC supply. The power factor is -

A solution of urea (molar mass 56 g/mol) boils at 100.18°C at the atmospheric pressure. If Kf and Kb of water are 1.86 and 0.52 K kgmol−1 respectively, the above solution will freeze at

Two men start from two points p and q. 8km apart and walk towards each other. They meet in 80 mins. If they walk in the same direction they meet in 2 hours. Find the speed of each man.

Sir I want to ask that on rubbing a glass with fur or rubbing ani two such materials, why is charge generated on it and why that charge only.

A helium nucleus makes a full rotation in a circle of radius 0.8 m in 2 s. The value of magnetic field at the centre of the circle is

a point source of light at the surface of a sphere causes a parallel beam of light to emerge from the opposite surface of the sphere .Find the refracrive indexof the sphere

In the above problem if the lift moves up with an acceleration equal to the acceleration due to gravity, the reading on the spring balance will be

A current sheet →J=10^uyA/m lies on the dielectric interface x = 0 between two dielectric media with εr1=1,μr1=1 in Region -1 (x &lt; 0) and εr2=2,μr2=2 in Region-2 (x &gt; 0). If the magneitc field in Region-1 at x = 0+ is →H1=3^ux+30^uyA/m, the magnetic field in Region-2 at x=0+ is

If a gas is taken from A to C through B, then heat absorbed by the gas is 8 J. Heat absorbed by the gas in taking it directly from A to C is

44.Two charged conducting metallic conductors are kept at a separation r and Q1 and Q2 be the charges given. Then the potential energy of the system is?(r>>a)(r>>b)

A ball is dropped from height h on a horizontal floor. If it loses 60% of its energy on hitting the floor, find the height to which it will rise.

Find the moment of inertia for a semicircular disc of mass m and radius r about an axis passing through its centre of mass and perpendicular to the plane of disc

River of width d is flowing with velocity v0 as shown. A swimmer swims (with respect to water) perpendicular to the current with acceleration a=2t (where t is time) starting from rest from the origin O at t=0. The equation of trajectory of the path followed by the swimmer is

Electrical force between two charged spheres is 200 N.If we increase 10 % charge on one of the charged sphere and decrease 20 % charge in the other,then the electrical force between them for the same distance becomes

If the area bounded by the curves y=|cos−1(sinx)|+∣∣∣π2−(cos−1cosx)∣∣∣,x- axis and π2&lt;x&lt;π is equal to π2k , then k is -

A metallic sphere of radius r is charged so that potential at its surface is V. This charged sphere is enclosed by a concentric conducting shell of radius 2r. What is the potential of conducting shell when both are joined by a conducting wire

A metal bullet moving at 400 ms-1 strikes on a tree trunk and get embedded inside it. Assuming total kineticenergy is converted to heat and 50% of heat is absorbed by the bullet, the increase in its temperature willerkecttbe (specific heat capacity of metal 200 J kg K-1 and bullet not melts)

In the circuit shown in figure, L=10H, R=5Ω,E=15V. The switch S is closed at t=0. At t=2s, the current in the circuit is:

wo particles executing SHM of same amplitude of20 cm with same period along the same lineabout same equilibrium position. The maximumdistance between the two is 20 cm. Their phasedifference in radian is equal to

The string of a simple pendulum is held horizontal at a height and then released. The tension in the string when the bob is at the lowest point is

If ε0 and μ0 are respectively the permittivity and magnetic permeability of free space, ε and μ are the corresponding quantities in a medium. The refractive index of the medium is-

A motorbike is being chased by a car. The motorbike moves with the speed of 10 m/s and has acceleration of 5 m/s2. Whereas, the car has speed of 20 m/s and accelerates with 3 m/s2. If the initial separation between motorbike and car is 60 m, find the distance by which car will miss the motorbike.

A wheel rotation with uniform angular acceleration covers 50 revolutions in the first five seconds after the start. Find the angular acceleration and the angular velocity at the end of five seconds.

A series RLC circuit has inductance of 0.12 H, capacitance of 480 nF and resistance of 23 Ω is connected to a 230 V AC supply whose frequency can be varied. What is the source frequency for which current amplitude is maximum? Also, find the maximum value of current.

Coefficient of linear expansion of brass and steel rods are α1and α2 . Length of brass and steel rods are l1 and l2 respectively. If l2–l1 is maintained same at all temperatures, then find the ratio of α1 to α2.

A paticle falls from a height h upon a fixed horizontal plane and rebouns.If e is the coefficient of restitution, the total distance travelled before rebounding has stopped is ?

The half-life of 40K is 1.30 ×109 y. A sample of 1.00 g of pure KCI gives 160 counts s−1. Calculate the relative abundance of 40K (fraction of 40K present) in natural potassium.

What is fulrane

A particle is moving along x−axis. Its x−coordinate versus time graph is shown. Its v−t graph will be:

{ A small object of mass }m, at the end of a light cord, is held horizontally at a distance }r from a fixed support as }} shown. The object is then released. What is the tension in the cord when the object is at the lowest point of its } shing?

Three light bulbs (60 W,120 V) are connected across a 120 V power source. If the resistance of each bulb does not change with current, then find out total power delivered to the three bulbs.

If several capacitors are connected both in series and parallel combination . How to identify series connection and parallel connection in a complex circuit?

A particle is projected vertically up with velocity v=4gR/3 from earth surface. The velocity of particle at height equal to half of maximum height reach by it

X²-x+1 alpha ki power 2009and beta powe,is,2009 solve this

A charge Q is placed at each of the two opposite corners of a square. A charge q is placed at each of the other two corners. If the resultant force on each charge q is zero, then

Calculate screening constant sigma 3d electron of zn atom

Wavelength of a 1 keV photon is 1.24×10−9m. What is the frequency of 1 MeV photon

water pump driven by petrol raises water at a rate of 0.5m min-1 from a depth of 30 m. If the pump is 70%efficient, what power is developed by the engine? [Take g 9.8 ms-2]

A wire carrying current I has the shape as shown in the figure.Linear parts of the wire are very long and parallel to X-axis while semi-circular portion of radius R is lying in Y−Z plane. Magnetic field at point O is

A current sheet →J=10^uyA/m lies on the dielectric interface x = 0 between two dielectric media with εr1=1,μr1=1 in Region -1 (x < 0) and εr2=2,μr2=2 in Region-2 (x > 0). If the magneitc field in Region-1 at x = 0+ is →H1=3^ux+30^uyA/m, the magnetic field in Region-2 at x=0+ is

If the area bounded by the curves y=|cos−1(sinx)|+∣∣∣π2−(cos−1cosx)∣∣∣,x- axis and π2<x<π is equal to π2k , then k is -