1A torch bulb connected to two dry cells and a switch is left on for a while and then switched off. It is found to be warm. Why?
2After noting the power ratings of appliances used in your school, which appliance converts the most energy into other forms per second when working fully?
3Rohan finds 900 W written on the rice cooker in his kitchen. If the household potential difference is 220 V, find the current the rice cooker needs.
4What is the heating effect of electric current? Give two examples.
5Why is nichrome used to make the heating element of a heater?
6How does a filament bulb give light?
7What can happen to household wiring when the potential difference rises suddenly?
8Derive the formula \( P = IV \).
9An iron takes 5 A at 220 V. What is its power, and how much energy does it convert in one second?
10How much energy does a 60 W bulb convert in 10 seconds?