Question

Jack measured 1 amp as the total current in a certain circuit when he applied 20 volts to the circuit. When he applied 60 volts, he got a measurement of 3 amps. Write a linear equation describing the relation between voltage and current, and calculate the total current when 50 volts are applied to the circuit.

Answer 1

The linear equation is V - IR =0

The total current is 2.5 amps

Explanation:

According to ohms law, the voltage (V) applied is directly proportional to current (I)

Therefore, V = IR

V - IR = 0 (R is resistance)

When V = 20, I = 1

The 1st equation is 20 - R = 0

When V = 60, I = 3

The 2nd equation is 60 - 3R = 0

From the 1st equation, R = 20

Substiting R = 20, V = 50 into the linear relation V - IR = 0

50 - 20I = 0

50 = 20I

I = 50/20 = 2.5 amps