-
A 12 cm wire is given a shape of a right angled triangle ABC having sides 3 cm, 4 cm and 5 cm as shown in the figure. The resistance between two ends (AB, BC, CA) of the respective sides are measured one by one by a multi-meter. The resistances will be in the ratio of
-
- 3 : 4 : 5
- 9 : 16 : 25
- 27 : 32 : 35
- 21 : 24 : 25
Correct Option: C
Resistance is directly proportional to length
| 1 | = | 1 | = | 1 | = | (4 + 5) + 3 | |||
| RAB | 3 | 4 + 5 | (3)(4 + 5) |
| RAB = | = | |||
| 3 + (4 + 5) | 12 |
Similarly,
| RBC = | = | |||
| 4 + (3 + 5) | 12 |
| RAC = | = | |||
| 5 + (3 + 4) | 12 |
∴ RAB : RBC : RAC = 27 : 32 : 35
