Question

An ideal choke takes a current of `8A` when connected to an a.c. source of `100` volt and `50Hz`. A pure resistor under the same conditions takes a current of `10A`. If two are connected in series to an `a.c.` supply of `100V` and `40Hz`, then the current in the series combination of above resistor and inductor is
A. `10A`
B. `8A`
C. `5sqrt(2)`amp
D. `10sqrt(2)`amp

Answer 1

`X_(L)=(100)/(8)`, `R=(100)/(10)=10Omega`
`Lxx100pi=(100)/(8)` or `L=(1)/(8pi)H`
`Z=sqrt(((1)/(8pi)xx2pixx40)^(2)+10^(2))=10sqrt(2)`
`I=(E)/(Z)=(100)/(10sqrt(2))=5sqrt(2)A`