Quiz on Frequency Divider with JK Flip-Flops

What is the main function of each JK flip-flop in this circuit?

• Multiply the input frequency

• Temporarily store data

• Divide the frequency by 2

• Produce analog signals

With 3 JK flip-flops connected in cascade, the total frequency is divided by:

• 8

• 16

• 32

• 4

If the input signal has 20 Hz, the frequency at the final output (Q of the last flip-flop) will be:

• 10 Hz

• 1.25 Hz

• 0.625 Hz

• 0.25 Hz

What happens when J = 1 and K = 1?

• The flip-flop maintains the state

• The flip-flop toggles the state

• The output is forced to 0

• The relay is activated directly

What is the purpose of the NPN transistor in the circuit?

• Oscillate the flip-flop signal

• Act as a switch to activate the relay

• Reduce the frequency

• Divide the voltage of the lamp

Why is a diode used in parallel with the relay coil?

• Charge capacitors

• Protect against reverse voltage spikes

• Prevent the relay from activating

• Increase the relay current

What is the logic voltage used in the JK flip-flops (74HC73)?

• 5V

• 12V

• 3.3V

• 24V

What does the CLR (Clear) pin do in the JK flip-flop?

• Toggles the state

• Holds the output fixed

• Resets the output Q

• Amplifies the output

What would be the behavior if only 2 flip-flops were used?

• Division by 8

• Division by 2

• Division by 4

• Division by 16

What is the function of the relay in this circuit?

• Measure frequency

• Turn on/off a 12V load with a 5V command

• Multiply current

• Store