Page 60 - Physics - XII

Precautions

1. The electrical connections should be neat, clean, and tight.
2. The positive pole of battery and positive terminal of voltmeter must be connected with zero mark
(A end) of the potentiometer.
3. The jockey should be gently pressed over the potentiometer wire.

4. The reading of ammeter should remain constant throughout the experiment.

ACTIVITY - 6

Aim
To draw the diagram of a given open circuit comprising at least a battery, resistor/rheostat, key, ammeter
and voltmeter. Mark the components that are not connected in proper order and correct the circuit and also
the circuit diagram.

Apparatus and Materials Required
A battery eliminator or a battery, a rheostat, a resistor, a one-way key, an ammeter, a voltmeter, connecting
wires, and sand paper

Principle/Theory

An electrical circuit is working only if all the components of electric circuit are connected in proper order,
all the components and devices are in proper working condition, and the circuit is closed. An open circuit
means a break in some part of a circuit. This happens due to open key or broken wire or loose connection
or burnt out components. Some examples of open circuits are shown in Fig. 6.1(a) and (b).

V E K
– + + –
Rheostat
R +
A V
– + –

R
Rheostat

– +
E K + –
A
(a) (b)
Fig. 6.1: Open circuits

Procedure
1. Draw a circuit diagram in your practical notebook as given by your teacher or any of the circuits
given in Fig. 6.1.
2. Check which components are connected in proper order and which are not.
3. Make the corrections in the circuit diagram. Now, draw the corrected circuit diagram.

4. Now, connect all the components according to the corrected diagram.
5. After fi nal connection of the components, check whether the corrected circuit is functioning or not.

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