If in the circuit, power dissipation is $$150W,$$ then $$R$$ is

Tube $$A$$ has bolt ends open while tube $$B$$ has one end closed, otherwise they are identical. The ratio of fundamental frequency of tube $$A$$ and $$B$$ is

If an ammeter is to be used in place of a voltmeter, then we must connect with the ammeter a

The time period of a charged particle undergoing a circular motion in a uniform magnetic field is independent of its