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SAT Subject Test

The set of lettered choices below refers to multiple questions. Select the one lettered choice that best answers each question. A choice may be used once, more than once, or not at all in each set.

Which graph represents the total heat produced by a resistor carrying a steady current as a function of time from time ?

### Select an Answer

Correct Answer:

Yes

Correct Answer:

No

Correct Answer:

No

Correct Answer:

No

Correct Answer:

No

### View Correct Answer

The correct answer is a steadily increasing amount. The rate of heat dissipation by a resistor is equal to the power it expends. The power is related to the current and the resistance by the equation , so if the current is constant the power is constant. The total heat developed is then the power multiplied by the total time :

.

The graph is thus a steadily increasing function of time.

Question Difficulty:

easy