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

If an electron and a proton having same momentum enter perpendicular to a magnetic field, then

The power factor of $$AC$$ circuit having resistance $$(R)$$ and inductance $$(L)$$ connected in series and an angular velocity $$\omega $$ is

In a transformer, number of turns in the primary coil are $$140$$ and that in the secondary coil are $$280.$$ If current in primary coil is $$4A,$$ then that in the secondary coil is