Current Electricity Charging Discharging Of Capacitors Question 596

Question: A new flashlight cell of e.m.f. 1.5 volts gives a current of 15 amps, when connected directly to an ammeter of resistance $ 0.04,\Omega $ . The internal resistance of cell is

[MP PET 1994]

Options:

A) $ 0.04,\Omega $

B) $ 0.06,\Omega $

C) $ 0.10,\Omega $

D) $ 10,\Omega $

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Answer:

Correct Answer: B

Solution:

Let the internal resistance of cell be r, then $ i=\frac{E}{R+r} $

Therefore $ 15=\frac{1.5}{0.04+r} $

Therefore $ r=0.06\Omega $