A Series Circuit Consists of a 100-V DC Power Source

Multiple Choice

A series circuit consists of a 100-V DC power source, a 100-Ω resistor, and a variable resistor of resistance R, which varies from 0 to 100 Ω. The current in the circuit is ​ ​

A) directly proportional to R.
B) inversely proportional to R.
C) directly proportional to (100 Ω + R) .
D) inversely proportional to (100 Ω + R) .
E) neither directly nor inversely proportional to R or to (100 Ω + R) .