Physics Test - ...

An ideal choke takes a current of 10 A when connected to an ac supply of 125 V and 50 Hz. A pure resistor under the same conditions takes a current of 12.5 A. If the two are connected to an ac supply of 100 V and 40 Hz, then the current in series combination of above resistor and inductor is:

An infinite dielectric sheet having charge density o has a hole of radius \(\mathrm{R}\) in it. An electron is released on the axis of the hole at a distance \(\sqrt{3} R\) from the center. Find the speed with which it crosses the center of the hole.

Two bodies with moment of inertia I₁ and I₂(I₁>I₂) have equal angular momentum. If the KE of rotation is E₁ and E₂ , then :

Two straight conducting rails form a right angle where their ends are joined. A conducting bar in contract with the rails starts at the vertex at t = 0 and moves with constant velocity v along them as shown. A magnetic field B is directed into page. The induced emf in the circuit at any time 't' is proportional to:

In YDSE, the source S is not symmetrically placed from the slits S₁ and S₂ (in figure).

If the separation between slits and screen is D (d < < D), then

Electric potential in a region varies as V=(1500x² kVolt/m²). Total electric charge lying inside the cube of side 10 cm shown in figure is (ϵ0=8.9×10⁻¹²C²/Nm²) :

An aeroplane flying horizontally at a height of 980 m with velocity 100 m/s drops a food packet. A person on the ground is 100(√2−1) m ahead horizontally from the dropping point. At what velocity approximately should he move so that he can catch the food packet.

A current of 4A produces a deflection of 30^∘ in the galvanometer. The figure of merit is:

Block A of mass 2m is hanging from a vertical mass-less spring of spring constant ′k′ and is at rest. A block B of mass m strikes the given block of mass 2m with velocity ′u′ and sticks to it as shown. The magnitude of the acceleration of blocks just after collision is :

A uniform cylinder of mass M and radius R is placed on a rough horizontal board, which in turn is placed on a smooth surface. The coefficient of friction between the board and the cylinder is μ. If the board starts accelerating with constant acceleration a, as shown in the figure, then:

In a dark room with ambient temperature T₀, a black body is kept at a temperature T. Keeping the temperature of the black body constant (at T), Sun rays are allowed to fall on the black body through a hole in the roof of the dark room. Assuming that there is no change in the ambient temperature of the room, which of the following statements is correct?

A sphere of radius R is having charge Q uniformly distributed over it. The energy density of the electric field in the air, at a distance r (r > R) is given by (in J/m3) :

A uniform rod of mass M and length L is placed in a horizontal plane with one end hinged about the vertical axis. A horizontal force F=Mg/2 is applied at a distance F=5L/6 from the hinged end. The angular acceleration of the rod will be:

A block of mass M is pulled by a uniform chain of mass M tied to it by applying a force F at the other end of the chain. The tension at a point distant quarter of the length of the chain from free end will be:

An aeroplane flying at constant speed 105 m/s towards East, makes a gradual turn following a circular path to fly South. The turn takes 15 seconds to complete. The magnitude of the centripetal acceleration during the turn is