Class 12th

The fringe width in Young's double slit experiment increases when

If two coherent waves are represented by y₁ = 4sinωt and y₂= 3sin(ωt+π/3)interfere at a point, the amplitude of resulting wave will be about

A plane electromagnetic wave EZ = 100 cos (6 * 10⁸ t + 4x) V/m, where x is in metre and t is in second. propagates in medium, what is refractive index of the medium?

A coil has resistance of 30 ohm and inductive reactance 20 ohm at 50 Hz frequency. If an ac source of 200 V, 100 Hz is connected across the coil, current in coil will be

According to Lenz's law of electromagnetic induction

The horizontal component of earth's magnetic field at a place is 4 * 10^–4 T and dip is 45°. A metal rod of length 20 cm is placed in north south direction and is moved at constant speed of 5 cm/s towards East. What is e.m.f. induced in the rod?

The resistance of a silicon junction diode, whose V - I characteristics is as shown in figure is (V_k = 0.7 V)

The relative permeability of iron is 5500. What is its magnetic susceptibility?

Three long wires, carrying current 10 A, 20 A and 30 A are placed parallel to each other as shown. Point P and Q are in midway of wires. What is ratio of magnetic field at P to the Q?

Two identical cells connected in series send 10 A  current through a 5 W resistor. When they are connected in parallel, they send 8 A current through same resistance. What is internal resistance of each cell?