DieselShip's Online Content Library

Q7. A relay coil is connected across 10 V d.c. supply and starts to operate after 0.55 ms when the instantaneous current is 100 mA. The relay coil has a time constant of 5 ms.

Calculate EACH of the following:

(a) The final relay current;

(b) The resistance and inductance of the relay coil;

(c) In order to increase the operating, time a resistance of 40 Ω is connected in series with the relay coil. Calculate the new operating time assuming that the relay starts to operate when the instantaneous current is 100 mA.