Page 15 - 10-phy-14 Current Electricity

Procedure 5. Close the key K2. The deflection will become
Observations zero.
and Data
Processing 6. Adjust the shunt resistance RS so that the
deflection in the galvanometer is exactly the Why does the deflection
half. become zero on closing

7. Repeat the experiment by changing the the key K2
resistance R for another even value of
deflection. In this way take three more readings and record them.

No. High Deflection Shunt Deflection Resistance of
q Resistance Galvanometer
of Resistance q
Obs. (Div) RS 2 RG = RS
R
(W) (W)
(W)
1

2

3

Mean value of RG = …………. W

Conclusions

Post Lab. 1. Determine the resistance of the galvanometer by adjusting shunt
Activities resistance so that the deflection q is reduced to q .

3

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2. Resistance of the galvanometer is due to a coil fixed inside it. Why do not
we directly measure its resistance like an ordinary resistor?
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BRAIN TEASER
1. What will happen to the reading of an ordinary galvanometer if a

strong magnet is brought near it?
2. Can you measure the resistance of a voltmeter by half deflection

method?

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