Physics Test - ...

A proton of energy 200 MeV enters the magnetic field of 5 T. If direction of field is from south to north and motion is upward, then how much force will be acting on it?

An α particle and a proton travel with same velocity in a magnetic field perpendicular to the direction of their velocities, then what is the ratio of the radii of their circular path?

A wire of length 5m and radius 1mm has a resistance of 1 ohm. What length of wire of the same material at same temperature and of radius 2mm will also have a resistance of 1 ohm?

A very long straight wire carries a current I. When a charge +Q at point P has velocity  at the instant as shown in fig., then what is the force on the charge?

A cube of side 'b' has a charge 'q' at each of its vertices. What will be electric field due to this charge distribution at the centre of this cube?

What is the maximum kinetic energy of the positive ion in the cyclotron?

4 wires each of length 2 meter are bent into 4 loops P, Q, R and S and then suspended into uniform magnetic field. Same current is passed in each loop. Which of the following statement is correct?

Masses of 3 wires of same metal are in the ratio 1:2:3 and their lengths are in the ratio 3:2:1. What will be the ratio of electrical resistances?

2 wires are made up of two different materials whose specific resistance are in the ratio 2:3, length 3:4 and area 4:5. Find the ratio of their resistances.

An electron having charge 'e' and mass 'm' is moving in a uniform electric field E. What will be its acceleration?