Electrical Engineering - Energy and Power

Exercise : Energy and Power - General Questions
16.
For 12 V and 40 mA, the power is
480 mW
0.480 W
480,000 µW
all of the above
Answer: Option
Explanation:
No answer description is available. Let's discuss.

17.
A 220 resistor dissipates 3 W. The voltage is
73.3 V
2.5 V
25.7 V
257 V
Answer: Option
Explanation:
No answer description is available. Let's discuss.

18.
A 3.3 k resistor dissipates 0.25 W. The current is
8.7 mA
87 mA
8.7 µA
8.7 A
Answer: Option
Explanation:

W = I2R

I = square root(W/R)

= square root( 0.25/(3.3x1000) )

= 0.0087038828

= 8.7 mA


19.
A half-watt is equal to how many milliwatts?
5,000 mW
5 mW
500 mW
50 mW
Answer: Option
Explanation:
No answer description is available. Let's discuss.

20.
Three hundred joules of energy are consumed in 15 s. The power is
2,000 W
2 W
20 W
200 W
Answer: Option
Explanation:
No answer description is available. Let's discuss.