JEE Main Test 1...

In a ∆PQR, if 3 sin P + 4 cos Q = 6 and 4 sin Q + 3 cos P = 1, then ∠R is equal to

A pendulum bob carries a negative charge – q. A positive charge +q is held at the point of support. Then, the time period of the bob is

A whistle of frequency 540 Hz rotates in a horizontal circle of radius 2 mat an angular speed of15 rads ^-1. The highest frequency heard by a listener at rest with respect to the centre of circle
(velocity of sound in air = 330 ms ^-1)

A sheet of aluminium foil of negligible thickness is introduced between the plates of a capacitor. The capacitance of the capacitor

A certain current on passing through a galvanometer produces a deflection of 100 divisions. When a shunt of one ohm is connected, the deflection reduces to 1 division. The galvanometer resistance is

A step-down transformer is used on a 1000 V line to deliver 20 A at 120 V at the secondary coil. If the efficiency of the transformer is 80%, the current drawn from the line is

Quantity that remains unchanged in a transformer is

A horizontal straight wire 20 m long extending from East to West is falling with a speed of 5.0 ms^-1 , at right angles to the horizontal component of the earth's magnetic field 0.030 ×10^-4 Wbm^-2 . The instantaneous value of the emf induced in the wire will be

An electromagnetic wave is propagating along x-axis. At x = 1cm and t =10 s, its electric vector |E| = 6 V/m, then the magnitude of its magnetic vector is

A plane EM wave travels in free space along X-axis. At a particular point in space, the electric field along Y-axis is 9.3 Vm ^-1. The magnetic induction is