



Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
This lab manual provides a detailed guide on determining the resistance of a galvanometer using the half-deflection method and calculating its figure of merit. It includes a clear circuit diagram, step-by-step instructions, a sample data table, and calculations for both resistance and figure of merit. The manual also highlights precautions and potential sources of error, making it a valuable resource for students learning about electrical circuits and measurement techniques.
Typology: Summaries
1 / 6
This page cannot be seen from the preview
Don't miss anything!
DEMONSTRATOR/ LAB INCHARGE, LHTA
To determine Resistance of a Galvanometer by Half-Deflection Method and To find its Figure of Merit.
➢ Weston type Galvanometer ➢ A Battery (Battery Eliminator) ➢ High Resistance Box (0- 10000 Ohm’s) ➢ Low Resistance Box (0-200 Ohm’s) ➢ Two One-Way Keys ➢ A Voltmeter (0-3 V) ➢ Connecting Wires ➢ A piece of Sand Paper THEORY ➢ The Resistance of the given Galvanometer as found by half deflection method is given by G=(R×S)/(R-S) ➢ Where R is the resistance connected in series with the Galvanometer and S is the Shunt resistance. ➢ The Figure of Merit, k=E/[(R+G) θ ] ➢ Where E is the e.m.f. of the Cell and θ is the deflection produced with resistance R. ➢ The maximum current that can pass through the Galvanometer, Ig=nk ➢ Where n is the total no of division on the Galvanometer scale on either side of zero
N (θ) Divisions
(S) Ohm’s
(θ / 2) Divisions
Mean Resistance G = (106.8+106.4+106.2+105.8+105.6)/ = 530.8 / 5 = 106.1 Ohm’s
EMF of the Battery = 3.4 V Resistance of Galvanometer (G) = 106.1 Ohm’s n = 30 HIGH RESISTANCE (R) Ohm’s
( θ ) K=E/[(R+G)θ] A Div -^1 6100 30 1. 82 × 10-^5 7700 24 1.8 1 × 10-^5 10500 18 1. 78 × 10-^5 13500 14 1. 78 × 10-^5 19000 10 1. 78 × 10-^5 CALCULATION Resistance of the Galvanometer (G) = 106.1 Ohm’s Mean Figure Of Merit k= { (1.82+1.81+1.78+1.78+1.78) × 10