# Class 12 Physics Moving Charges and Magnetism: NCERT Solutions for Question 28

This page focuses on the detailed Moving Charges and Magnetism question answers for Class 12 Physics Moving Charges and Magnetism, addressing the question: 'A galvanometer coil has a resistance of 15 Ω and the metre shows full scale deflection for a current of 4 mA. How will you convert the metre into an ammeter of range 0 to 6 A?'. The solution provides a thorough breakdown of the question, highlighting key concepts and approaches to arrive at the correct answer. This easy-to-understand explanation will help students develop better problem-solving skills, reinforcing their understanding of the chapter and aiding in exam preparation.
Question 28

## A galvanometer coil has a resistance of 15 Ω and the metre shows full scale deflection for a current of 4 mA. How will you convert the metre into an ammeter of range 0 to 6 A?

Resistance of the galvanometer coil, G = 15 Ω

Current for which the galvanometer shows full scale deflection,

= 4 mA = 4 × 10-3 A

Range of the ammeter is 0, which needs to be converted to 6 A.

Current, I = 6 A

A shunt resistor of resistance S is to be connected in parallel with the galvanometer to convert it into an ammeter. The value of S is given as:

Hence, a  10mΩ shunt resistor is to be connected in parallel with the galvanometer.