A current of 2A flows through a 2Ω resistor when connected across a battery

⇦

⇨

A current of 2A flows through a 2Ω resistor when connected across a battery. The same battery supplies a current of 0.5A when connected across a 9Ω resistor. The internal resistance of the battery is

Options

(a) 0.5Ω
(b) 1/3Ω
(c) 1/4Ω
(d) 1Ω

Correct Answer:

1/3Ω

Explanation:

Let the internal resistance of the battery be r. Then the current flowing through the circuit is given by
i = E / R + r
In first case, 2 = E / 2 + r …(i)
In second case, 0.5 = E / 9 + r … (ii)
From (i) & (ii), 4 + 2r = 4.5 + 0.5r
1.5r = 0.5
r = 1/3Ω

Related Questions:

1. For principal quantum number n=3, the possible values of orbital quantum number
2. An electric dipole is placed at an angle 30°with an electric field intensity 2×10⁵N/C.
3. X-rays when incident on a metal
4. Photons with energy 5eV are incident on a cathode C in a photoelectric cell.
5. The difference in the variation of resistance with temperature in a metal

Topics: Current Electricity (136)
Subject: Physics (2479)

---

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

---

Share this page with your friends