Series & Parallel Resistors — Homi Bhabha Class 9 Physics MCQs with Solutions
Free Homi Bhabha Class 9 Physics Series & Parallel Resistors MCQs with step-by-step solutions (8 questions). Part of Electricity & Magnetism. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Series & Parallel Resistors · medium · numerical
Three resistors of 2 Ω, 3 Ω and 5 Ω are joined in series. Their combined resistance is:
A. 10 Ω ✓ Correct
B. 1 Ω
C. 0.97 Ω
D. 30 Ω
Solution: In series, resistances add: $2 + 3 + 5 = 10$ Ω.
Q2 — Series & Parallel Resistors · hard · numerical
Two 6 Ω resistors are connected in parallel. Their equivalent resistance is:
A. 6 Ω
B. 12 Ω
C. 36 Ω
D. 3 Ω ✓ Correct
Solution: For two equal parallel resistors, $R = \dfrac{6}{2} = 3$ Ω.
Q3 — Series & Parallel Resistors · hard · numerical
A 2 Ω and a 3 Ω resistor are connected in parallel. The equivalent resistance is:
A. 1.2 Ω ✓ Correct
B. 2.5 Ω
C. 5 Ω
D. 6 Ω
Solution: $\dfrac{1}{R} = \dfrac{1}{2} + \dfrac{1}{3} = \dfrac{5}{6} \Rightarrow R = \dfrac{6}{5} = 1.2$ Ω.
Q4 — Series & Parallel Resistors · medium · theory
In a series circuit, the quantity that is the same through every component is the:
A. potential difference
B. resistance
C. current ✓ Correct
D. power
Solution: In series the same current flows through all components, while the voltage divides among them.
Q5 — Series & Parallel Resistors · hard · numerical
Three 2 Ω resistors are connected in series across a 12 V battery. The current in the circuit is:
A. 18 A
B. 6 A
C. 2 A ✓ Correct
D. 0.5 A
Solution: Total resistance $= 2 + 2 + 2 = 6$ Ω; current $= \dfrac{12}{6} = 2$ A.
Q6 — Series & Parallel Resistors · easy · theory
When resistors are connected in series, which quantity is the same through each resistor?
A. the voltage across each resistor
B. the current ✓ Correct
C. the resistance
D. the power dissipated
Solution: In a series circuit there is only one path, so the same current flows through every resistor; the voltage divides among them.
Q7 — Series & Parallel Resistors · medium · numerical
Two resistors of 6 ohm and 3 ohm are connected in parallel. What is their combined resistance?
A. 18 ohm
B. 4.5 ohm
C. 9 ohm
D. 2 ohm ✓ Correct
Solution: 1/R = 1/6 + 1/3 = 1/6 + 2/6 = 3/6 = 1/2, so R = 2 ohm. A parallel combination is always less than the smallest resistor.
Q8 — Series & Parallel Resistors · hard · numerical
Three equal resistors of 12 ohm each are used. Two are connected in parallel, and that combination is in series with the third. What is the total resistance?
A. 30 ohm
B. 18 ohm ✓ Correct
C. 4 ohm
D. 36 ohm
Solution: Two 12 ohm resistors in parallel give 12/2 = 6 ohm. In series with the third 12 ohm resistor: 6 + 12 = 18 ohm.