JEE MainPhysicsCurrent Electricity
A battery of 24 V is connected in a series circuit containing a fixed resistor of 1 k and N identical resistors, each of resistance 50 . If the potential difference across a combination of 5 such identical resistors is 4 V , the value of N is:
Options
- A30
- B4
- C10
- D5
Correct answer
C. 10
Step-by-step solution
Let the total number of 50 resistors be N . The equivalent resistance of the entire series circuit is: R_ eq = 1000 + 50N The current flowing through the circuit is: I = 24 1000 + 50N The resistance of the 5 identical resistors is: R₅ = 5 50 = 250 The potential difference across these 5 resistors is given as 4 V . Using Ohm's law: V₅ = I R₅ 4 = ( 24 1000 + 50N ) 250 Solving for N : 4 = 6000 1000 + 50N 1000 + 50N = 1500 50N = 500 N = 10 Answer: 10