Question

The values of geometric centre frequency and lower cut-off frequency of an amplifier are 800 Hz and 100 Hz respectively. The upper cut-off frequency is:

A. 6.4 kHz
B. 12.8 kHz
C. 3.2 kHz
D. 10 kHz

Answer 1

To determine the upper cut-off frequency when the centre frequency is 800 Hz and the lower cut-off frequency is 100 Hz, we use the formula: Upper cut-off frequency = (Centre frequency)^2 / Lower cut-off frequency, leading to an answer of 6.4 kHz.

Step-by-step explanation:

The question asks about determining the upper cut-off frequency of an amplifier given the geometric centre frequency and the lower cut-off frequency. In this case, the geometric centre frequency is 800 Hz and the lower cut-off frequency is 100 Hz. The geometric centre frequency, also known as the geometric mean, is the square root of the product of the lower and upper cut-off frequencies. Therefore, to find the upper cut-off frequency, we can use the formula:

Upper cut-off frequency (fh) = (Centre frequency)2 / Lower cut-off frequency

Substituting the given values:

fh = (800 Hz)2 / 100 Hz = 640000 Hz / 100 Hz = 6400 Hz

So the upper cut-off frequency is 6400 Hz, which corresponds to option A: 6.4 kHz.