BMST - Basic Math and Science Electrical Circuits and Ohm's Law Questions and Answers 4 — Questions and Answers
Question 1: What is the total power dissipated by a 4 Ω resistor carrying 3 A of current?
- 12 W
- 36 W (Correct answer)
- 48 W
- 6 W
Correct answer: 36 W
P = I²R = 3² × 4 = 9 × 4 = 36 W.
Question 2: Which of the following best describes an open circuit?
- A circuit with no resistance
- A complete path for current to flow
- A broken path that stops current flow (Correct answer)
- A circuit with infinite current
Correct answer: A broken path that stops current flow
An open circuit has a break in the path, preventing any current from flowing.
Question 3: In a parallel circuit, if one branch burns out, what happens to the other branches?
- They all stop working
- They continue to operate normally (Correct answer)
- They draw less current
- The voltage drops to zero
Correct answer: They continue to operate normally
In a parallel circuit, each branch has its own path, so other branches are unaffected by one branch failing.
Question 4: Three 6 Ω resistors are connected in series. What is the total resistance?
- 2 Ω
- 6 Ω
- 12 Ω
- 18 Ω (Correct answer)
Correct answer: 18 Ω
Series total resistance = 6 + 6 + 6 = 18 Ω.
Question 5: What does a short circuit occur when?
- Resistance is very high
- Current has a near-zero resistance path (Correct answer)
- Voltage is extremely low
- The circuit is broken
Correct answer: Current has a near-zero resistance path
A short circuit occurs when current finds an unintended low-resistance path, causing dangerously high current flow.
Question 6: According to Ohm's Law, if resistance doubles while voltage stays constant, what happens to current?
- Current doubles
- Current stays the same
- Current is halved (Correct answer)
- Current quadruples
Correct answer: Current is halved
Since I = V/R, doubling R while V is constant cuts I in half.
Question 7: A wire carries 2 A of current for 30 seconds. How much charge passes through it?
- 15 C
- 32 C
- 60 C (Correct answer)
- 90 C
Correct answer: 60 C
Charge Q = I × t = 2 × 30 = 60 coulombs.
BMST - Basic Math and Science Electrical Circuits and Ohm's Law Questions and Answers 4
What is the total power dissipated by a 4 Ω resistor carrying 3 A of current?