18. The most accurate instrument for comparing the e.m.f of two cells is the..
19. Which of the following devices may be used to convert Ac to
DC(a) A reheostat (b) A diode (c) An alternator (d) A resistor.
20. In a hollow conductor, the charge is discharge on the end part of the outer surface of the conductor because of..... (a) force
1 answer
of repulsion between like charges (b) force of attraction between unlike charges (c) induction (d) polarization.
1 answer