If three resistors of 15 Ω, 35 Ω and 50 Ω are connected in series to a 25-V battery, what is the current flowing in the circuit?

Question

Question

This question was previously asked in

RRB JE CBT 2 (Mechanical Engineering) ReExam Official Paper (Held On: 04 Jun, 2025)

Answer 1

The Correct answer is 0.25 A.

Key Points

When resistors are connected in series, their resistances add up. The total resistance in the circuit is calculated as:
Total Resistance, R = R₁ + R₂ + R₃, where R₁ = 15 Ω, R₂ = 35 Ω, R₃ = 50 Ω.
Substituting the values, R = 15 Ω + 35 Ω + 50 Ω = 100 Ω.
The current flowing in the circuit can be calculated using Ohm's Law, which states:
I = V / R, where I is the current, V is the voltage, and R is the total resistance.
Given that the voltage of the battery is 25 V, we substitute the values to find the current:
I = 25 V / 100 Ω = 0.25 A.
Thus, the current flowing in the circuit is 0.25 A, which is the correct answer.
This calculation is significant in understanding the behavior of resistors in series circuits and applying Ohm's Law effectively.

Additional Information

Ohm's Law
- Ohm's Law states that the current passing through a conductor between two points is directly proportional to the voltage across the two points, provided the temperature remains constant.
- Mathematically, it is expressed as V = IR, where V is the voltage, I is the current, and R is the resistance.
- It is one of the fundamental principles used in electrical and electronic circuits.
Series Circuits
- In a series circuit, the same current flows through all the components connected in the series.
- The total resistance is the sum of individual resistances, which increases as more resistors are added.
- Such circuits are used in applications where equal current flow through all components is required, like in string lights.