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. One solid sphere A and another hollow sphere B are of same mass and same outer radii.
2. What is the energy of He⁺ electron in first orbit?
3. The potential difference that must be applied to stop the fastest photoelectrons
4. A 5 watt source emits monochromatic light of wavelength 5000Å. When placed
5. The coefficient of mutual inductance of two coils is 6 mH. If the current flowing

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