Question
Two resistors have a combined resistance of 34Ω when connected in series. The same resistors have a combined resistance of 7.4Ω when connected in parallel.
What is the resistance of one of the resistors?
(A) 15Ω
(B) 17Ω
(C) 23Ω
(D) 27Ω
▶️Answer/Explanation
Ans: A
Question
Kirchhoff’s first law states that the sum of the currents entering a junction in a circuit is equal to the sum of the currents leaving it.
The law is based on the conservation of a physical quantity.
What is this physical quantity?
(A) charge
(B) energy
(C) mass
(D) momentum
▶️Answer/Explanation
Ans: A
Question
Three identical cells each have electromotive force (e.m.f.) E and negligible internal resistance.
The cells are connected to three identical resistors, each of resistance R, as shown.
What is the potential difference across one of the resistors?
(A) $0$
(B) $\frac{E}{3}$
(C) $\frac{2E}{3}$
D $E$
▶️Answer/Explanation
Ans: B
Question
Kirchhoff’s first law is a consequence of the conservation of which quantity?
(A) charge
(B) energy
(C) momentum
(D) potential difference
▶️Answer/Explanation
Ans: A