A body of mass 2 kg is thrown up vertically with K.E of 490 joules If the acceleration due to gravity is 9.8 m/s2 the height at which the K.E of the body becomes half its original value is give by:
A photocell with a constant p.d of V volt across it illuminated by a point source from a distance of 25 cm. When the source is moved to a distance of 1 m, the electrons emitted by the photocell
In an AC circuit a resistance of R ohm i connected in series with an inductance L if phase angle between voltage and current be 45o the value of inductive reactance will be
The primary winding of transformer has 500 turns whereas its secondary has 5000 turns The primary is connected to an a.c supply of 20 V, 50 Hz The secondary will have an output of
