we turn on a power supply and provide 175.12 joules of thermal energy for 13.20

Question

we turn on a power supply and provide 175.12 joules of thermal energy for 13.20 seconds at 18.95 volts to a carbon resistor initially a 22.3 C. calculate the work done by the power supply, the current and resistance of the resistor. (assume that the temperature of the resistor remains costant during these 13.20 secondons, even though it would burn if we actually did this. the resistor will be immersed in liquid nitrogen during experiment so this will not happen.) show formula for each calculation

W=?

I=?

R=?

Explanation / Answer

Work done is same as the thermal energy supplied by the power supply.
W = 175.12 J

Power = Voltage x Current
Power = W/time = 175.12 / 13.2 = 13.27 W
Voltage = 18.95 V
Current = Power/Voltage = 13.27 / 18.95 = 0.7 A

Using Ohm's law, V = IR
R = V/I = 18.95 / 0.7 = 27.1 Ohm.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.