Answer :
Final answer:
The phase for the high-pass transfer function at 89 Hz is 90° since the capacitor causes voltage and current to be 90° out of phase in a low-frequency RC circuit.
Explanation:
For the high-pass transfer function, the phase at a frequency of 89 Hz is close to 90°. This is because at low frequencies, the capacitor in a pure RC circuit causes the voltage and current to be 90° out of phase. Therefore, the correct answer is (a) 90°. In a high-pass filter, the phase shift is dependent on the frequency.
At low frequencies, the capacitor dominates the circuit, resulting in a 90° phase shift between the voltage and current. Therefore, the correct answer is a) 90°.