In an alternating current circuit consisting of elements in series, the current increases on increasing the frequency of supply. Which of the following elements are likely to constitute the circuit ?

Options

A. Only resistor.
B. Resistor and an inductor.
C. Resistor and a capacitor.
D. Only a capacitor.

Answer

C, D

Explanation

The current increases on increasing the frequency of supply. Hence, the reactance of the circuit must be decreases as increasing frequency.
For a capacitive circuit,
`X_C=1/(2pivC)`
When the frequency increases `X_C` decreases and
For a R-C circuit,
`Z=sqrt(R^2+(1/(omegaC))^2)=sqrt(R^2+(1/(2pivC))^2)`
when frequency increases X decreases.
Because, circuit only with resistance if the resistance does not changes and frequency changes current does not changes. Moreover,circuit with inductor as the frequency increases its reactance increases and hence current decreases but not increases.