Question 1

Kirchhoff's Current Law states that the sum of the currents into a junction must equal the sum of the currents out of that junction.

Accepted Answer

A) True 
 B)False

Question 2

If four 100 W lamps are connected in parallel across a 120 V source, what is the total current?

Accepted Answer

A) 833 mA 
B) 33.3 A 
C) 8.33 A 
D) 3.33 A

Question 3

If three equal resistors are connected in parallel across 12 V, each resistor drops 4 V.

Accepted Answer

A) True 
 B)False

Question 4

In a parallel circuit, total power PT is calculated as:

Accepted Answer

A) P1 × P2 × P3 × etc. 
B) 1/P1 + 1/P2 + 1/P3 + etc. 
C) P1 ÷ P2 ÷ P3 ÷ etc. 
D) P1 + P2 + P3 + etc.

Question 5

If a 470 Ω resistor, 680 Ω resistor and 830 Ω resistor are connected in parallel, the total resistance equals .

Accepted Answer

A) 1150 Ω 
B) 1510 Ω 
C) 1980 Ω 
D) 208 Ω

Question 6

Each branch in a four -branch parallel circuit carries 10 mA. If one of the branches opens, then the current in each of the other three branches equals .

Accepted Answer

A) 30 mA 
B) 10 mA 
C) 0 A 
D) 13.33 mA

Exam 5: Parallel Circuits