Question

What is happening if energy input remains constant and voltage remains the same in a circuit, but the current decreases?
A. The resistance has increased.
B. The volts have decreased.
C. The power has increased.

Answer 1

im checking my textbook right now

Answer 2

i want to say it is A or C

Answer 3

i think its A

Answer 4

Use the various expressions for electrical power in terms of voltage \(V\), current \(I\) and resistance \(R\)

\[P=VI=I^2R=\frac{V^2}{R}\]

Power is constant, voltage is constant, current is decreasing, there's only one thing left that can change.

Answer 5

It sorta tells you in the question that 2 of the answers are wrong.

"Energy input is the same"

"voltage remains the same"

Answer 6

A because it is resistance has increased

Answer 7

can i get a badge plz :)

Answer 8

It has to be A... although I think there's something wrong with the question. Hang on a second.

Answer 9

thxx

Answer 10

thank you both

Answer 11

\(P = I^2R\) remains constant
\(V=IR\) remains constant
If \(I\) decreases by half \(I\to\frac12 I\)
then in order to conserve power, \(R \to 4R\) so \(P = (\frac12 I)^2\times4 R = I^2R\)
and in order to conserve voltage \(R \to 2R\) so \(V=\frac12 I\times2R = IR\)

Resistance cannot both double and quadruple. The question describes an impossible circuit.