An alternating electric field, of frequency $$v$$, is applied across the does (radius = R) of a cyclotron that is being used to accelerate protons (mass = m). The operating magnetic field (B) used in the cyclotron and the kinetic energy (K) of the proton beam, produced by it, are given by

Two similar coils of radius R are lying concentrically with their planes at right angles to each other. The currents flowing in them are $$I$$ and 2$$I$$, respectively. The resultant magnetic field induction at the centre will be

A milli voltmeter of 25 milli volt range is to be converted into an ammeter of 25 ampare range. The value (in ohm) of neccessary shunt will be

A square loop, carrying a teady current $$I$$, is placed in a horizontal plane near a long straight conductor carrying a steady current $$I$$₁ at a distance d from the conductor as shown in figure. The loop will experience