Physics Past Questions and Answers

The relationship between the directions of magnetic field, the current-carrying wire in the field is easily remembered using

The current in the primary coil of a transformer is 2.5A. If the coil has 50 turns and the secondary250 turns, calculate the current in the secondary coil. Neglect energy losses in the transformer

In a photocell, light energy is converted to

Two identical waves traveling in the same direction are superimposed. What should be the phase difference between the waves for maximum destructive interference to occur?

When a resistor of resistance R is connected across a cell, the terminal p.d of the cell is reduced to three quarters of its e.m.f. The internal resistance of the cell is expressed as