Series vs Parallel - Comparison - UNSOLVED PRACTICE SET
Chapter: Electricity | Topic: Series vs Parallel Comparison
SERIES VS PARALLEL - COMPARISON - UNSOLVED PRACTICE SET
Topic: Series vs Parallel Comparison
Multiple Choice Questions
Q1. In which circuit arrangement does the equivalent resistance INCREASE when more resistors are added?
- Parallel only
- Both series and parallel
- Series only
- Neither - resistance stays the same
Q2. Domestic wiring is done in parallel because:
- Parallel is cheaper
- Each appliance gets full supply voltage and can be controlled independently
- Parallel reduces total current
- Series circuits are more dangerous
Q3. In which arrangement is the current the same through all components?
- Parallel
- Neither
- Both
- Series
Q4. In which arrangement is the voltage the same across all components?
- Series
- Parallel
- Neither
- Both
Q5. Two resistors of 10 Ω and 40 Ω are available. To get an equivalent resistance of 8 Ω, they should be connected in:
- Series
- Parallel
- Either - same result
- Cannot be achieved with these values
Q6. If one component fails (open circuit) in a series string, and one component fails in a parallel branch:
- Both arrangements go completely dark
- Series circuit loses all other components; parallel circuit — other branches continue
- Parallel circuit loses all; series circuit — other components continue
- Neither is affected
Short Answer Questions
Q7. Compare series and parallel circuits in terms of:
(a) current,
(b) voltage, and
(c) equivalent resistance. Present as a mini comparison table.
Q8. Two resistors of 6 Ω and 12 Ω are connected
(a) in series and
(b) in parallel across 12 V.
Find the equivalent resistance for each arrangement.
Q9. Why is the equivalent resistance in parallel always less than any individual resistance? Why is the equivalent resistance in series always greater?
Q10. A student connects three identical bulbs — first in series, then in parallel — across the same battery. In which arrangement do the bulbs glow brighter? Explain using resistance and current.
Q11. String lights (Diwali lights) were historically in series; modern ones are in parallel. Give two specific advantages of modern parallel Diwali lights over old series ones.
Q12. In a combined circuit, a 6 Ω and a 3 Ω resistor are in parallel, and this combination is in series with a 4 Ω resistor. Find the total resistance.
Long Answer Questions
Q13. Present a detailed comparison of series and parallel circuits under the following headings:
(a) definition and circuit diagram description,
(b) equivalent resistance formula and whether it increases or decreases when more resistors are added,
(c) current distribution,
(d) voltage distribution,
(e) effect of one component failing, and (f) two practical applications of each type in Indian households.
Q14. A student has a 12 V battery, three resistors (4 Ω, 6 Ω, 12 Ω) and wants to find the circuit arrangement that delivers:
Case 1: the lowest possible total current.
Case 2: the highest possible total current.
(a) For Case 1, which arrangement is used? Calculate the current.
(b) For Case 2, which arrangement is used? Calculate the current.
(c) Calculate power delivered by the battery in each case.
(d) Which arrangement is more 'efficient' for delivering power to all resistors simultaneously?
(e) Describe one real-life Indian context where you would deliberately choose each case.
Q15. A complex circuit has the following arrangement across a 24 V supply: R₁ = 4 Ω in series with a parallel combination of R₂ = 6 Ω and R₃ = 12 Ω.
(a) Find the equivalent resistance of the parallel part.
(b) Find the total resistance of the circuit.
(c) Find the total current from the battery.
(d) Find the voltage across the parallel combination.
(e) Find the current through R₂ and R₃.
(f) Verify that I₂ + I₃ = total current.
Numerical / Application-Based Problems
Q16. A class 10 student measures: Series 4 Ω + 6 Ω gives total R = 10 Ω; Parallel 4 Ω ‖ 6 Ω gives total R = 2.4 Ω. Both connected to 12 V.
(a) Calculate current for each.
(b) Calculate total power for each.
(c) Calculate voltage across each resistor in series.
(d) Calculate current through each resistor in parallel.
(e) Confirm that the parallel arrangement draws more current from the battery.
Q17. Five identical 10 Ω resistors are available. Show how to connect them (describe the arrangement) to achieve: (a) 50 Ω, (b) 2 Ω, (c) 10 Ω (using all five in a mixed arrangement.
hint: some in series, some in parallel). Show calculations for each.
Q18. An Indian village has three street lamps (each 100 Ω) connected to a 220 V supply by a wire of total resistance 5 Ω (the feeder line).
(a) Calculate the equivalent resistance of the three lamps in parallel.
(b) Add the feeder line resistance to find total circuit resistance.
(c) Calculate the total current.
(d) Calculate the voltage drop across the feeder line.
(e) Calculate the actual voltage each lamp receives. Why are the lamps dimmer than expected at 220 V?