Question

The function performed by the following arrangement of J-K flip-flop is

(Assume initially all flip-flops are cleared)

• A. MOD-1 counter
• B. MOD-2 counter
• C. MOD-3 counter
• D. Shift register

Answer 1

The correct option is C MOD-3 counter

From the given diagram,

$J_1=\overline{Q_1}{Q}_2$
$K_1=\overline{Q_2}$
$J_2=K_2=\overline{Q_1}$

Also given, $Q_1=0;Q_2=0$ initially

Clk	$Q_1$	$Q_2$	$J_1$	$K_1$	$J_2$	$K_2$
0	0	0	0	1	1	1
1	0	1	1	0	1	1
2	1	0	0	1	0	0
3	0	0	0	1	1	1

$\therefore$ It is MOD-3 counter.