beginning of content:
SAT Subject Test
A single resistor is connected to a battery as shown above. The current is
and the power dissipated as heat is
. The circuit is changed by doubling the emf
of the battery while
is kept constant.
After the change, the current is
Select an Answer
Correct Answer:
No
Correct Answer:
No
Correct Answer:
No
Correct Answer:
Yes
Correct Answer:
No
View Correct Answer
The correct answer is . In this series circuit with just one resistor, the emf across the battery is equal to the voltage
across the resistor, so if the emf is doubled so is
. The current
in the resistor is given by Ohm’s law,
, so if
is doubled while the resistance
remains constant, then
is also doubled.
Question Difficulty:
medium