Question

The maximum allowed rms current in a circuit before its circuit breaker trips is 12.5 A . If a maximum emf of 180 V is connected to a device whose resistance is 8.4 ohms, will the circuit breaker trip and interrupt the flow of electricity

Answer 1

The circuit will break .

Step-by-step explanation:

The potential difference of 180 V is applied across resistance = 8.4 ohm

Thus the maximum current flowing I₀ =
`(V)/(R)` =
`(180)/(8.4)` = 21.4 A

The rms value of the current is =
`(I_0)/(√(2) )` = I₀ x 0.7 = 15 A

This value of current is greater than the 12.5 A . Thus the circuit will break .