IB Physics SL B.5.4 Ohmic behaviour Question Bank
Practise IB Physics SL B.5.4 by stating Ohm’s law and deciding whether components are ohmic from current–voltage graphs.
- Syllabus
- First assessment 2025
- Course
- Physics SL
- Level
- SL
Practise IB Physics SL B.5.4 by stating Ohm’s law and deciding whether components are ohmic from current–voltage graphs.
Part 2 Electric current and resistance
The graph below shows how the current I in a tungsten filament lamp varies with potential difference V across the lamp.

Explain whether or not the filament obeys Ohm's law.
Ohm's law states that voltage is directly proportional to current or potential difference / resistance is a constant;
graph not linear / gradient not constant so Ohm's law not obeyed / calculation of V/I at two points showing that they are different;
Award [0] for bald statement of Ohm's law not obeyed.