A circuit has a voltage drop of 60.0 V across an 80.0 Ω resistor that carries a current of [tex]$0.750 \AA$[/tex]. What is the power used by the resistor?
A. 4800.0 W
B. 45.0 W
C. 60.0 W
D. 2.00 W
Answer (1)
The problem provides the voltage drop and current through a resistor.
Power is calculated using the formula P = V \ttext x I .
Substituting the given values, P = 60.0 \ttext V \ttext x 0.750 \ttext A = 45.0 \ttext W .
The power used by the resistor is 45.0 W .
Explanation
Problem Analysis We are given the voltage drop across a resistor and the current flowing through it. We need to find the power used by the resistor.
Formula Introduction The power P used by a resistor can be calculated using the formula: P = V × I where V is the voltage drop across the resistor and I is the current flowing through it.
Calculation We are given that the voltage drop V = 60.0 \ttext V and the current I = 0.750 \ttext A . Substituting these values into the formula, we get: P = 60.0 \ttext V × 0.750 \ttext A P = 45.0 \ttext W
Final Answer Therefore, the power used by the resistor is 45.0 W.
Examples
Understanding power consumption in circuits is crucial for designing efficient electronic devices. For example, when designing a smartphone, engineers need to minimize power usage to extend battery life. By calculating the power used by each component, they can optimize the circuit design to reduce overall energy consumption, ensuring the phone lasts longer on a single charge. This involves using resistors and other components that efficiently manage voltage and current to minimize power loss.
