If `400 Omega` of resistance is made by adding four `100 Omega` resistance of tolerance `5%`, then the tolerance of the combinations

Options

A. 0.05
B. 0.1
C. 0.15
D. 0.2

Answer

A

Explanation

`100 Omega` resistance with tolerance of 5% can be written as `R= 100 Omega +- 5 Omega`
In series combinatin resistances are directly added and we should be aware of the fact that errors are always added. Hence we can write resultant of series combinatin of four as follows:
`R_(S) = 400 Omega +- 20 Omega`
Percentage error or tolerance can be written as:
`(20)/(400) xx 100 = 5%` Thus, option (a) is correct