3-ELE-07
Contents
Outcomes
- Pupils can ...
- Pupils can ...
Specification References
2.6 recall and use the relationship, power = current x voltage, P=IV and apply the relationship to the selection of appropriate fuses
Starter
Reminder from previous lesson that Power = IV. A couple of calculations done in there rough books to get students using the equation again and to check any who are struggling with this. Light bulbs have power ratings eg 100W, 40W. What does this mean?
Question: Does a 100W bulb always give out power of 100W?
Main Body of Lesson
- Power output of a bulb
Intro to practical: Use an ammeter and voltmeter to measure I and V of a bulb while changing V. Will need to show a clear circuit diagram to help them set up. (Could use variable supply power supply with set voltages 2V to 12V instead of a voltmeter. No need then for voltmeter or variable resistor.)
Record values of V and I and note the brightness of the bulb each time. Leave a column to calculate Power = IV each time.
Plot V against I.
What have students noticed about power of the bulb?
Plenary
Homework
Additional Information
Resources Required
Textbook References
Website References
Skills Addressed
Observation and recording of results. Graph plotting.