16.A coil of wire of radius R has 200 turns and a self-inductance of 108 mH. The self-inductance of a similar coil of 500 turns will be:

17.When the speed of the coil of generator is increased

18.One 10 V, 60 W bulb is to be connected to 100 V line. The required self-inductance of induction coil will be: (f = 50 Hz)

19.The time constant of C-R circuit is:

20.A 50 Hz AC current of crest value 1 A flows through the primary of a transformer. If the mutual inductance between the primary and secondary be 0.5 H, the crest voltage induced in the secondary is: