A circuit with a resistance of 6 Omega has a fuse that melts at 8 A. Can a voltage of 21 V be applied to the circuit without blowing the fuse?

Jan 9, 2016

It works without melting.

Explanation:

To solve it, we apply the resistance formula:
$\text{Resistance" = "Voltage"/"Current}$
If "Current >= 8, the circuit wont work.

So, we check the limit of the voltage, when Current is 8, and if the voltage is higher than 21, the circuit will work:
$6 = \text{Voltage"_("limit")/8 => "Voltage} = 6 \cdot 8 = 48 V$

So, 21 < 48. It works without melting.