Shift the switch to 3V position
15.- LED and lamp connected in series
Turn the switch 15 on, the LED 17 will light up but not the lamp. It is
because the LED only needs a small quantity of current and the lamp
needs higher than LED and the circuit only handle small quantity of
current.
16.- Unidirectional conductivity of a LED
Reverse the LED, turn the switch 15 on, both LED and lamp will not light
up. It is because the Led is unidirectional in conductivity, it only allows
the current fl ow from positive to negative pole, but not reversed.
ENGLISH-16