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. A point performs simple harmonic oscillation of period T and the equation of motion
2. Calculate the charge on equivalent capacitance of the conbination shown in figure
3. A coin placed on a rotating turn table just slips,if it is placed at a distance
4. The dual nature of light is exhibited by
5. Light from the constellation Virgo is observed to increase in wavelength by 0.4%

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