A proton,a electron and an α particle accelerated through the same potential difference enter a region of uniform magnetic field,moving at right angles to the magnetic field B.The ratio of their kinetic energies is:
A train is moving away from a station at 25 m/s-1and sounding a whistle of frequency 1000 Hz. What will be the apparent frequency as heard by an observer on the platform? (speed of sound 340 m/s-1)
As circular coil has 250 turns and a mean diameter of 20 cm. If carries a current of 5A. What is the strength of the magnetic field at a point on its axis at a distance of 5m from the centre of the coil ?
Two point charge +3μC and +8μC repel each other with a force of 40 N if a charge of -5μC us added to each of them then the force between them will become
A lift is moving downwards at a very high constant speed. A passenger present inside the lift standing on a weighing machine would notice that his weight