Page 2 - 10-phy-14 Current Electricity
P. 2
Materials Nichrome wire (of resistance not less than 10W), voltmeter (0 – 15 V), ammeter
Required (0 – 0.6 A), rheostat (50 ohm), power supply (0 – 12V, 1A), key, connecting wires and
sand paper.
1. Draw the circuit diagram as shown in Fig.14.1.1.
2.
Procedure Make connections according to the circuit diagram. Nichrome wire is
3. used as a conductor.
4. Before starting the experiment, bring the slider of the rheostat to its
middle.
DO YOU KNOW? 5. Turn the power supply ON. Slowly rotate its Why should the slider of the
knob till the voltmeter shows a reading of 6 rheostat be kept in the
Insulators are materials 6. volts. middle?
that resist the flow of
current. They protect us 7. Close the key. A current should flow through
from harmful effects and 8. the circuit as indicated by the ammeter.
prevent current leakage.
Insulators include rubber, Adjust the rheostat so that the current in the circuit remains within the
plastic, dry wood, cotton, range of ammeter.
paper, clay etc.
Note the readings of voltmeter (V) and ammeter (I).
Determine the resistance R of nichrome wire for each reading by using
the formula
R=V
L
9. Take four more readings by changing the resistance of the rheostat.
Observations No. of Obs. Voltmeter reading Ammeter reading Resistance of conductor
and Data V I
Processing 1 R=V
2 (V) (A) I
3
(W)
4
5
Mean resistance R = ------------------- W.
Graph
Draw a graph for V versus I.
31
Required (0 – 0.6 A), rheostat (50 ohm), power supply (0 – 12V, 1A), key, connecting wires and
sand paper.
1. Draw the circuit diagram as shown in Fig.14.1.1.
2.
Procedure Make connections according to the circuit diagram. Nichrome wire is
3. used as a conductor.
4. Before starting the experiment, bring the slider of the rheostat to its
middle.
DO YOU KNOW? 5. Turn the power supply ON. Slowly rotate its Why should the slider of the
knob till the voltmeter shows a reading of 6 rheostat be kept in the
Insulators are materials 6. volts. middle?
that resist the flow of
current. They protect us 7. Close the key. A current should flow through
from harmful effects and 8. the circuit as indicated by the ammeter.
prevent current leakage.
Insulators include rubber, Adjust the rheostat so that the current in the circuit remains within the
plastic, dry wood, cotton, range of ammeter.
paper, clay etc.
Note the readings of voltmeter (V) and ammeter (I).
Determine the resistance R of nichrome wire for each reading by using
the formula
R=V
L
9. Take four more readings by changing the resistance of the rheostat.
Observations No. of Obs. Voltmeter reading Ammeter reading Resistance of conductor
and Data V I
Processing 1 R=V
2 (V) (A) I
3
(W)
4
5
Mean resistance R = ------------------- W.
Graph
Draw a graph for V versus I.
31
