The heating element in a battery-powered packaging sealer is made from two sections of nichrome strip connected in series. The supply maintains a potential difference of 15 V across the complete element.
| section of strip | resistance |
|---|---|
| narrow section | 18 Ω |
| wide section | 7.0 Ω |
Calculate the current delivered by the supply while the sealer is operating.
Calculate how much energy the narrow section transfers to its thermal store each second.
Explain which section of the strip takes more energy from each coulomb of charge that passes through it.
The sealer operates continuously for 4.0 minutes. Calculate the energy delivered to the complete heating element during this time.
105 exam-style questions on Edexcel GCSE Physics 10.3 Electrical energy and power, covering 10.3.1 The heating effect of an electric current, 10.3.2 Reducing energy transfer in wires, 10.3.3 Advantages and disadvantages of the heating effect, 10.3.4 Energy transferred by an electrical circuit, 10.3.5 Electrical power, and 10.3.6 Energy transfers in domestic devices. Each one has a worked solution and a mark scheme showing where the marks go.