A circuit with a resistance of 7 Omega has a fuse melts at 6 A. Can a voltage of 21 V be applied to the circuit without blowing the fuse?

Feb 15, 2016

Yes

Explanation:

This is an application of Ohm's Law, which states that the voltage $V = I \cdot R$ where $I$ is the current and $R$ is the resistance.

$21 = I \cdot 7$ to calculate what current the stated voltage will produce.

$I = \frac{21}{7} = 3 A$

$3 A < 6 A$

There fore the fuse will not blow.