Electricity Exam Questions

Question 1

State and explain whether a filament lamp is an ohmic or non-ohmic conductor up to its working power.

Answer 1

filament lamp is a non-ohmic conductor as current is not (directly) proportional to voltage

resistance is not constant

Question 2

State what happens to the resistance of the filament lamp as the current increases.
[1 ]

Answer 2

resistance (of filament lamp) increases

Question 3

Filament lamps P and Q are connected in parallel. R is in series to the circuit.

When filament lamp in q melts why does p get brighter and r get dimmer?

Answer 3

either
circuit/total resistance increases
(hence) current decreases and pd/voltage across R decreases

OR
resistance of PQ combination increases
(hence) greater share of pd/voltage across lamp P