Eduqas A-Level Electronics Digital systems overview quiz quiz

$1$

Undefined

$0$

It depends on the clock

$\overline{A} + \overline{B}$

$A \cdot B + \overline{A} \cdot \overline{B}$

$\overline{\overline{A} \cdot \overline{B}}$

$\overline{A} \cdot \overline{B}$

Any logic function can be built from only NANDs or only NORs

They are the fastest switching gates available in any logic family

They use the least power of all the standard logic gates

They always have exactly three separate inputs

Sum $= A \cdot B$, carry $= A \oplus B$

Sum $= A \oplus B$, carry $= A \cdot B$

Sum $= A + B$, carry $= A \cdot B$

Sum $= A \oplus B$, carry $= A + B$

Generating a stable clock signal for a sequential circuit

Storing a single bit of data between clock edges

Minimising a Boolean expression by grouping adjacent 1s

Counting the number of clock pulses received over time

$S = 0, R = 0$

$S = 1, R = 0$

$S = 0, R = 1$

$S = 1, R = 1$

Toggles

Holds its current output state unchanged on every clock edge

Sets the output Q to logic 1 and keeps it there

Resets the output Q to logic 0 regardless of the clock

$5$

$10$

$25$

$32$

It always needs more flip-flops than a synchronous counter to count to the same value

Cumulative propagation delay limits its speed and causes glitches

It can never count higher than 8 no matter how many stages are used

It has no clock input driving any of its stages

$69\ \text{Hz}$

$1.4\ \text{kHz}$

$686\ \text{Hz}$

$2.1\ \text{kHz}$

$1.1\ \text{s}$

$0.1\ \text{s}$

$1.0\ \text{s}$

$11\ \text{s}$

Invert all the bits only, leaving the result in one's complement

Invert all the bits, then add 1

Add 1 to the original number without inverting any bits

Swap the first and last bits and leave the rest unchanged