JEE PYQ: Magnetism And Matter Question 21
Question 21 - 2019 (11 Jan 2019 Shift 2)
A galvanometer having a resistance of $20,\Omega$ and $30$ division on both sides has figure of merit $0.005$ ampere/division. The resistance that should be connected in series such that it can be used as a voltmeter upto $15$ volt, is:
(1) $100,\Omega$
(2) $120,\Omega$
(3) $80,\Omega$
(4) $125,\Omega$
Show Answer
Answer: (3) $80,\Omega$
Solution
$I_g = nk = 0.005 \times 30 = 0.15$ A, $15 = 0.15(20 + R)$, $R = 80,\Omega$
BETA
