electrical resistance

Question 1

how does current vary with voltage in wires, resistors, metal filament lamps and diodes
How can this be experimented

Answer 1

if you increase the resistance the current will decrease
resisters metal filament lamps and diodes all create resistance so will decrease the current
It can be experimented using an ammeter and measuring the current with and without these components or w differnt voltage levels

Question 2

what can lamps and leds indicate

Answer 2

the presence of a current in a circuit