Page 14 - 10-phy-14 Current Electricity

As the galvanometer shows half deflection, so IG = I
2

Therefore,

1 = I ´ RS
2 RS + RG

or 2RS = RS + RG

or RG = RS

Materials Galvanometer, dry cell, high resistance box (0-10kΩ), low resistance box (0-500Ω),
Required 2 one-way keys and connecting wires.

DO YOU KNOW? IG RG IG I
I
An ordinary galvanometer G Is
has a coil and a Is 1KW
permanent magnet. 2mA RS
When the current passes LRB
through the coil, a K2
magnetic field is
generated which interacts R V
with the magnetic field of HRB +-
the magnet as a result of
which the coil rotates. A K1
digital meter has no coil Fig. 14.4.2
and no magnet. It does
not work upon the Assemble the circuit as shown in Fig. 14.4.2. Keep the key K1 open
magnetic effect of and K2 closed.
current. It is based on the
working of a digital circuit Take a high resistance R from the resistance box
known as Analog to Digital (HRB).
Converter (ADC).

1.

Procedure 2.

3. Close the key K1 and open the key K2. Why a high resistance is
4. taken out from the
Adjust the resistance R, so that the resistance box before
galvanometer shows a high even number closing the key K1?
deflection . Now the whole current I is passing
through the galvanometer.

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