Question

The electrical current, in amperes, in a circuit varies directly as the voltage. When 5 volts are applied, the current is 15 amperes. What is the current when 18 volts are applied?

Answer 1

Using Ohm's law, the current when 18 volts are applied is found to be 54 amperes, calculated by multiplying the proportionality constant (3 A/V) by the new voltage (18 V).

Step-by-step explanation:

The current in a circuit varies directly as the voltage, according to Ohm's law, which states that the current I in amperes in a circuit is directly proportional to the voltage V applied to it.

Since we know that 5 volts produce 15 amperes, we can find the proportionality constant by dividing the current by the voltage (15 A / 5 V = 3 A/V).

This constant is the conductance, and it allows us to calculate the current for any other voltage.

To find the current when 18 volts are applied, we can use the proportionality constant we found (3 A/V). We multiply this constant by the new voltage: current = (3 A/V) x (18 V) = 54 amperes.