Question

A relay of resistance 6 Ω operates with a minimum current of 0.030 A. It is...

A relay of resistance 6 Ω operates with a minimum current of 0.030 A. It is required that the relay operate when the current in the line attains 0.240 A. What resistance should be used to shunt the relay?

Homework Answers

Answer #1

Relay of resistance 6 ohm operates with a current of 0.03 A.

Hence, voltage across the relay is

Now to increase the current to 0.24 A let us add a shunt of resistance R in parallel to the relay.

As the shunt is connected in parallel equivalent resistance is

So, current in the circuit is,

This is the resistance that must be used.

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