Concept featured in film:Electrical circuits, shorts, electrical safety hazards

VHS: 33:50-35:38

Play Flickclip Here (Quicktime)

Summary of clip: In this memorable scene, Clark is trying to turn on his festive exterior illuminations. After several attempts, Clark is unable to turn the Christmas lights on and is unable to find the problem. Clark's mom walks in the garage to turn the light on and the house lights up. Clark's wife (and his unsuspecting neighbors) get to see the house lit up in all it's glory. Then, Clark's mom turns the switch off. Finally, Clark realizes the problem and turns the switch back on which keeps the house aglow.

Connection of flickclip to the concept: This clipcan be used to talk about circuits, short circuits, electrical wiring in the home, switches, and electrical hazards in the home.

Suggestions to Teachers:

1. Suggested questions for students when viewing the clip:

a. If just one of the 25,000 bulbs burnt out, what would have happened? Why? Are the lights connected in series or parallel?

b. What are the safety hazards shown on this film clip? Why are they hazardous? How might Clark address those safety issues?

2. Application:

Have the students research how much power (in watts) a 100-bulb strand of holiday lights use. Use that number to figure out how much power 25,000 bulbs use. Have the students research the price of electricity as measured in kilowatts/hr. What would the Griswolds have to pay to light their house for an hour? Assume that the Griswolds light their house each evening from 7 pm until 10 pm for two weeks. What will that cost them? The teacher may want to play the portion of the clip that shows the Griswolds' meter spinning rapidly as well as the town's electric company switching to auxillary nuclear power!