Question

need a detailed answer..Find the READING in Voltmeter if current flowing is 4A. Those who don't know it, STAY AWAY....​

Answer 1

We use ohm's law to solve this problem. Since the incoming current is 4A, we say I=4A. The voltmeter reads a voltage drop of 20V across the resistor. This means that if we apply ohm's law on the resistor, we can say that V=I*R. Therefore, 20=4*R. This gives us that value of R to be 5 ohms.

This was the theoretical ideal case. Now, with non ideal meters, in the real world temperature increases and so the resistance also increases.