BMST - Basic Math and Science Electrical Circuits and Ohm's Law Questions and Answers 3 — Questions and Answers
Question 1: A circuit has a voltage of 24 V and a resistance of 8 Ω. What is the current flowing through the circuit?
- 2 A
- 3 A (Correct answer)
- 4 A
- 6 A
Correct answer: 3 A
Using Ohm's Law, I = V/R = 24/8 = 3 A.
Question 2: Two resistors of 10 Ω and 20 Ω are connected in parallel. What is the equivalent resistance?
- 30 Ω
- 15 Ω
- 6.67 Ω (Correct answer)
- 5 Ω
Correct answer: 6.67 Ω
For parallel resistors, 1/R = 1/10 + 1/20 = 3/20, so R = 20/3 ≈ 6.67 Ω.
Question 3: What happens to the total resistance when you add more resistors in series?
- It decreases
- It stays the same
- It increases (Correct answer)
- It becomes zero
Correct answer: It increases
In a series circuit, total resistance is the sum of all resistors, so adding more increases it.
Question 4: A light bulb has a resistance of 240 Ω and operates on 120 V. What power does it consume?
- 30 W
- 60 W (Correct answer)
- 90 W
- 120 W
Correct answer: 60 W
P = V²/R = 120²/240 = 14400/240 = 60 W.
Question 5: In a series circuit with a 12 V battery and two resistors of 3 Ω and 9 Ω, what is the voltage drop across the 9 Ω resistor?
- 3 V
- 6 V
- 9 V (Correct answer)
- 12 V
Correct answer: 9 V
Total R = 12 Ω, I = 1 A; voltage across 9 Ω = 1 × 9 = 9 V.
Question 6: Which unit is used to measure electrical resistance?
- Ampere
- Volt
- Ohm (Correct answer)
- Watt
Correct answer: Ohm
Electrical resistance is measured in Ohms (Ω), named after Georg Simon Ohm.
Question 7: A toaster draws 5 A from a 110 V outlet. What is its resistance?
- 22 Ω (Correct answer)
- 44 Ω
- 55 Ω
- 550 Ω
Correct answer: 22 Ω
R = V/I = 110/5 = 22 Ω.
BMST - Basic Math and Science Electrical Circuits and Ohm's Law Questions and Answers 3
A circuit has a voltage of 24 V and a resistance of 8 Ω.
What is the current flowing through the circuit?