A galvanometer has a coil of resistance 100 ohm and gives a full scale deflection for 30 mA current. If it is to work as a voltmeter of 30 volt range, the resistance required to be added will be

A galvanometer havings a coil resistance of 60 $$\Omega $$ shows full scale deflection when a current of 1.0 amp passes through it. It can be converted into an ammeter to read currents upto 5.0 amp by

The magnetic force acting on a charged particle of charge $$-$$2 $$\mu $$C in a magnetic frield of 2 T acting in y direction, when the particle velocity is $$\left( {2\widehat i + 3\widehat j} \right) \times {10^6}\,m{s^{ - 1}}$$

Under the influence of a uniform magnetic field, a charged particle moves with constant speed v in a circle of radius R. The time period of rotation of the particle