JEE PYQ: Magnetism And Matter Question 13
Question 13 - 2019 (12 Apr 2019 Shift 1)
A galvanometer of resistance $100,\Omega$ has $50$ divisions on its scale and has sensitivity of $20,\mu$A/division. It is to be converted to a voltmeter with three ranges, of $0-2$V, $0-10$ V and $0-20$ V. The appropriate circuit to do so is:
(1) $R_1 = 2000,\Omega$, $R_2 = 8000,\Omega$, $R_3 = 10000,\Omega$
(2) $R_1 = 1900,\Omega$, $R_2 = 9900,\Omega$, $R_3 = 19900,\Omega$
(3) $R_1 = 1900,\Omega$, $R_2 = 8000,\Omega$, $R_3 = 10000,\Omega$
(4) $R_1 = 19900,\Omega$, $R_2 = 9900,\Omega$, $R_3 = 1900,\Omega$
Show Answer
Answer: (3) $R_1 = 1900,\Omega$, $R_2 = 8000,\Omega$, $R_3 = 10000,\Omega$
Solution
$i_g = 20 \times 50 = 1000,\mu A = 1$ mA. Using $V = i_g(G + R)$: $R_1 = 1900,\Omega$, $R_2 = 8000,\Omega$.
BETA
