Physics Circle home Student Login

Home›Chapters›Current Electricity PYQs›Kirchhoff's Laws & Measuring Instruments›Question 46

JEE Main 2024 (1 Feb, Shift 2) · Kirchhoff's Laws & Measuring Instruments

Kirchhoff's Laws & Measuring Instruments question from JEE Main 2024 (1 Feb, Shift 2)

Q46JEE Main 2024 · 1 FEB · SHIFT 2Easy

Kirchhoff's Laws & Measuring Instruments

In an ammeter, 5%5\% of the main current passes through the galvanometer. If resistance of the galvanometer is GG, the resistance of ammeter will be:

Show answer and solution

Answer: (c)

  1. Ig=0.05I=I20I_g = 0.05I = \frac{I}{20}, so S=IgGI−Ig=G19S = \frac{I_g G}{I - I_g} = \frac{G}{19}.
  2. RA=SGS+G=G/19⋅GG/19+G=G20R_A = \frac{SG}{S + G} = \frac{G/19 \cdot G}{G/19 + G} = \frac{G}{20}
  3. So the answer is (c) G20\frac{G}{20}.
Report a mistake

More questions on Kirchhoff's Laws & Measuring Instruments