Katie wants to buy the right headlamp bulb as a spare for her motorcycle. If the circuit in the motorcycle runs off a standard 12 V battery, and one of the headlights is switched on, current flowing through the headlight is measured at 3.75 A. What is the power usage of the headlamp? Report the answer to two significant digits.

Answer 1

To find the power usage of the headlamp, you can use the formula for electrical power:

\[ P = V \times I \]

where:

• \( P \) is the power in watts (W),
• \( V \) is the voltage in volts (V), and
• \( I \) is the current in amperes (A).

Given that:

• \( V = 12 , \text{V} \)
• \( I = 3.75 , \text{A} \)

Substituting these values into the formula:

\[ P = 12 , \text{V} \times 3.75 , \text{A} = 45 , \text{W} \]

The power usage of the headlamp is 45 W. Reporting this to two significant digits, the final answer is:

\[ \text{Power usage} = 45 , \text{W} \]