By using only two resistance coils-singly, in series, or in parallel one should be able to obtain resistances of 3, 4, 12 and 16 ohms. The separate resistances of the coil are

Options

A. 3 and 4
B. 4 and 12
C. 12 and 16
D. 16 and 3

Answer

b

Explanation

When resistances `4Omega` and `12 Omega` are connected in series `= 4 + 12 = 16 Omega`
When these resistance are connected in parallel.
`(1)/(R_(p))=(1)/(4)+(1)/(12)impliesR_(p)=(4xx12)/(4+12)=(4xx12)/(16)=3Omega`