how many bits are required to sample an incoming signal 4000 times per second using 64 different amplitude level

6 bits

Explanation:

The quality of digitized signal can be improved by reducing quantizing error. This is done by increasing the number of amplitude levels, thereby minimizing the difference between the levels and hence producing a smoother signal.

Also, Sampling frequently (also known as oversampling) can help in improving signal quality.

To get the number of bits, we use:

2ⁿ = amplitude level

where n is the number of bits.

Given an amplitude level of 64, hence:

2ⁿ = 64

2ⁿ = 2⁶

n = 6 bits

v=ir = 3x15 =45 v