Question

In the formula below, P represents the electric power of a light bulb measured in watts, V is the voltage, and I is the current in amperes. P = VI A 90-watt light bulb has a current of 6 amperes and a voltage of 15 volts. If the voltage of the 90-watt light bulb doubles, what will happen to the current?

A. The current will double.
B. The current will halve.
C. The current will remain the same.
D. The current will quadruple.

Answer 1

If the voltage of a 90-watt light bulb is doubled, the current will halve in order to maintain the same power level of 90 watts according to the formula P = VI.

Step-by-step explanation:

In the formula P = VI, where P stands for electric power in watts, V is the voltage, and I is the current in amperes, we see a direct relationship between these quantities. Given a 90-watt light bulb operating at a voltage of 15 volts and a current of 6 amperes, if we double the voltage, according to the power formula, the current would not need to double to maintain the same power level. Instead, the current would halve, because power (P) is held constant at 90 watts, and the doubled voltage (V) would balance the reduction in current (I) to maintain the equation P = VI. Therefore, if the voltage of the 90-watt light bulb doubles, the current will halve to maintain the same power output of 90 watts.