Edexcel A-Level Product Design Systems and mechanisms overview quiz quiz

A light-emitting diode (LED) indicator

A light dependent resistor (LDR)

A piezo buzzer

A geared DC motor

$140$ ohms

$200$ ohms

$350$ ohms

$450$ ohms

It decreases

It stays constant

It becomes zero

It increases

AND

OR

NOT

NOR

3

6

8

9

It can never be reprogrammed once it has been soldered onto the board

Its behaviour is changed by editing software rather than rewiring

It always needs many more discrete components than fixed logic

It can only ever handle a single input signal

First class

Third class

It is not a lever

Second class

Rotary into reciprocating or oscillating

Steady linear sliding motion directly into rotary

Reciprocating motion back into continuous rotary

Oscillating motion into linear sliding only

$1:3$

$3:1$

$1:60$

$20:1$

$8000$ rpm

$2000$ rpm

$500$ rpm

$250$ rpm

It increases speed too

It increases efficiency above 100 per cent

It changes the direction of current

It reduces output speed

The belt can slip and stretch, so the ratio is not exact

It cannot transmit rotary motion between two parallel shafts

It always gives a positive, slip-free drive with an exact ratio

It cannot change the output speed relative to the input