NTA Abhyas JEE Main2020PhysicsCurrent ElectricityPractice
The maximum and the minimum equivalent resistance obtained by combining n identical resistors of resistance R , are R max and R min respectively. The ratio R max R min is equal to
Options
- An
- Bn 2
- Cn 2 - 1
- Dn 3
Correct answer
B. n 2
Step-by-step solution
To get maximum equivalent resistance all resistance must be connected in series ∴ R e q m a x = R + R + R + … n R . = n R To get minimum equivalent resistance all resistances must be connected in parallel. ∴ 1 R e q m i n = 1 R + 1 R + 1 R + … 1 n , 1 R e q m i n   = n R ⇒ R e q m i n = R n ∴ R e q m a x R e q m i n = n R R / n = n 2