Electricity | Activities in Text Book with Solution
Activity 12.1
Set up a circuit as shown in Fig. 12.2, consisting of a nichrome wire XY of length, say 0.5 m,
an ammeter, a voltmeter and four cells of 1.5 V each. (Nichrome is an alloy of nickel, chromium,
manganese, and iron metals.)
an ammeter, a voltmeter and four cells of 1.5 V each. (Nichrome is an alloy of nickel, chromium,
manganese, and iron metals.)
 |
| Fig. 12.2 |
First use only one cell as the source in the circuit. Note the reading in the ammeter I, for the current and reading of the voltmeter V for the potential difference across the nichrome wire XY in the circuit. Tabulate them in the Table given.
Next connect two cells in the circuit and note the respective readings of the ammeter and voltmeter for the values of current through the nichrome wire and potential difference across the nichrome wire.
Repeat the above steps using three cells and then four cells in the circuit separately.
Calculate the ratio of V to I for each pair of potential difference V and current I.
|
Number of
cells used |
Current
through the nichrome wire, I (ampere) |
Potential
difference |
V/I |
|
1 |
|||
|
2 |
|||
|
3 |
|||
|
4 |
✅ Answer:
|
Number of
cells used |
Current
through the nichrome wire, I (ampere) |
Potential
difference |
V/I |
|
1 |
0.5 |
1.5 |
3 |
|
2 |
1.0 |
3.0 |
3 |
|
3 |
1.5 |
4.5 |
3 |
|
4 |
2.0 |
6.0 |
3 |
In each case, V/I
value is approximately the same.
V–I graph is a straight line. Thus, V/I is a constant ratio.
