(Easy) true or false: 2 resistors connected in parallel?

Question

A circuit consists of 2 resistors, R1 and R2, connected in parallel across a battery. Which statement is FALSE:

A) Greater power is produced in the smaller resistor
B) If you place another resistor in series w/ R1 and R2 you will increase the overall resistance of the circuit.
C) If you place another resistor in parallel with R1 and R2 you will decrease the overall resistance of the circuit
D) If the battery is ideal, and you disconnect R2's branch entirely from the circuit, the power dissipated in R1 will NOT change.
E) If the battery is non-ideal and you disconnect R2's entire branch from the circuit, the voltage difference across R1 will decrease.

*I was guessing E if false.

Answer 1

E is false because the internal resitance is in series with R1. The decrease in current will cause a decrease in the voltage drop across the internal resistance, thus increasing the batteries terminal voltage.

A and D are obvious from Power = V * V / R

Answer 2

letter C is the false statement, proof: adding a parallel (or series) of resistors in the systems will again add up the overall resistance of the circuit. Formula for parallel resistance circuits ( R = R1 + R2 + R3 . . . + RN) ; for series ( 1/R = 1/R1 + 1/R2 + 1/R3 . . . + 1/RN)



So everything adds up, how do you say that the overall resistance decreases?

Answer 3

E. For a non-ideal battery you have to take the internal resistance of the battery into account.

Answer 4

reatt got his formulas bass-ackwards...adding a resistor will decrease the overall.

Answer 5

E is the only false statement.

Answer 6

I would guess E also but it was a long time ago when I took that class