In a parallel LC circuit, if the input signal frequency is increased above resonant frequency then ___________

The correct answer is: A. XL increases and XC decreases.

In a parallel LC circuit, the inductive reactance (XL) is inversely proportional to the frequency, while the capacitive reactance (XC) is directly proportional to the frequency. Therefore, if the input signal frequency is increased above resonant frequency, the inductive reactance will increase and the capacitive reactance will decrease.

Here is a more detailed explanation of each option:

• Option A: XL increases and XC decreases. This is the correct answer, as explained above.
• Option B: XL decreases and XC increases. This is incorrect, as the inductive reactance will increase when the frequency is increased.
• Option C: Both XL and XC increase. This is incorrect, as the inductive reactance will increase and the capacitive reactance will decrease when the frequency is increased.
• Option D: Both XL and XC decrease. This is incorrect, as the inductive reactance will increase and the capacitive reactance will decrease when the frequency is increased.