PHYSICS CONNECTION
Where does a battery’s power go?
The power supplied by a source is split between the external circuit and heating inside the source. Internal resistance makes the split depend on current.
εI = VI + I²r
Follow the reasoning
- Calculate the current using the external and internal resistances.
- Calculate power delivered to the load using terminal voltage.
- Compare it with the internal heating rate I²r.
OFFICIAL OCR QUESTIONS
Try it in a past paper 1
Open the question, then use its mark scheme to check your work.
Question 7
Connect a resistor network to internal resistance, drift speed, charge and dissipated energy.
A curated collection checked against the question papers and mark schemes; not a complete past-paper catalogue. Links open official OCR PDFs in a new tab.
ORIGINAL PHYSICSUK QUESTIONS
Put the ideas to work
More practice is on its way
No PhysicsUK question linked yet. New eligible questions appear here as the bank grows.
Specification outcomes (3)
- 4.3.2(c)(i) Use and apply E = I(R + r) and E = V + Ir for internal resistance.
- 4.2.5(a) Use and apply power equations P = IV, P = I²R, and P = V² / R.
- 4.2.5(b) Use energy transfer equation W = VIt.