Question

With a 200 kHz clock frequency, eight bits can be serially entered into a shift register in ________

(a) 4 μs

(b) 40 μs

(c) 400 μs

(d) 40 ms

The question was asked in a national level competition.

I would like to ask this question from Shift Registers in portion Registers of Digital Circuits

Answer 1

Right answer is (b) 40 μs

To elaborate: f = 200 KHZ; T = (1/200) m sec = (1/0.2) micro-sec = 5 micro-sec;

In serial transmission, data enters one bit at a time. After 8 clock cycles only 8 bit will be loaded = 8 * 5 = 40 micro-sec.