# 25 Lecture

## 2-INPUT 4-BIT MULTIPLEXER

Asynchronous preset and clear inputs are signals used in digital circuits to set or reset the output state of a flip-flop or latch regardless of the clock input. When the preset input is activated, the output becomes set, while activating the cl

## Important Mcq's Midterm & Finalterm Prepration Past papers included

1. What are asynchronous preset and clear inputs? a. Inputs that are synchronized with the clock signal b. Inputs that are not synchronized with the clock signal c. Inputs that set the output to a random state d. Inputs that change the clock frequency Solution: b. Inputs that are not synchronized with the clock signal What is the purpose of asynchronous preset and clear inputs? a. To introduce timing issues in the circuit b. To set or reset the output of a flip-flop or latch regardless of the clock signal c. To change the clock frequency d. To generate random input signals Solution: b. To set or reset the output of a flip-flop or latch regardless of the clock signal Which input is used to set the output of a flip-flop or latch to 1? a. Clear b. Preset c. Clock d. Data Solution: b. Preset Which input is used to reset the output of a flip-flop or latch to 0? a. Clear b. Preset c. Clock d. Data Solution: a. Clear What happens when both the preset and clear inputs of a flip-flop are activated at the same time? a. The output becomes set b. The output becomes reset c. The output remains unchanged d. The flip-flop enters an unpredictable state Solution: d. The flip-flop enters an unpredictable state Which type of flip-flop has asynchronous preset and clear inputs? a. D flip-flop b. JK flip-flop c. T flip-flop d. SR flip-flop Solution: d. SR flip-flop How can hazards be avoided when using asynchronous inputs? a. By slowing down the clock signal b. By synchronizing the asynchronous inputs with the clock signal c. By increasing the voltage of the asynchronous inputs d. By removing the asynchronous inputs from the circuit Solution: b. By synchronizing the asynchronous inputs with the clock signal What is the function of a latch? a. To store data b. To generate clock signals c. To count pulses d. To generate random numbers Solution: a. To store data Which input of a latch is used to set the output to 1? a. Clear b. Preset c. Clock d. Enable Solution: b. Preset Which input of a latch is used to reset the output to 0? a. Clear b. Preset c. Clock d. Enable Solution: a. Clear