MCQ practice · SSC Physics Board questions · Chapter 11: Current Electricity
How many 100 Ω resistors must be joined in parallel to get the resistance equal to that of two 5 Ω resistors joined in series?
Think it through first, then pick an option.
- a 5
- b 10
- c 20
- d 50
Answer and explanation
Correct answer: b 10
Two 5 Ω in series give 10 Ω; n resistors of 100 Ω in parallel give 100 ÷ n = 10, so n = 10.
Why the other options are wrong
- a 5: With 5 the value would be 100 ÷ 5 = 20 Ω; 10 Ω is needed, so 10 resistors.
- c 20: With 20 the value would be 100 ÷ 20 = 5 Ω; 10 Ω is needed, so 10 resistors.
- d 50: With 50 the value would be 100 ÷ 50 = 2 Ω; 10 Ω is needed, so 10 resistors.
Your account is open, so all 30,000+ MCQs from every chapter are yours. Start practising SSC Physics →
Want to keep going?
A free account carries you on to the next questions and opens 30,000+ MCQs from every chapter. Join before launch and Chirkut bundles are 60% off.
The ones you missed, worth one more look