Labs from Chicago, Fall 1993 :
Electrical Energy Quiz.

Dr. Rich Kron, Dr. Heidi Newberg, and Luisa Rebull
Labs written for the CARA Space Explorers, Fall 1993

This is meant to be handed out to the students.

constant you might need :
C of water = 1 calorie/(° C gram)
[1 calorie = 4.2 Joules = 42,000,000 (4 x 10^7) ergs]
formulas you might need :
Elec.Energy = (Elec.Power) x t
Elec.Power = V^2/R
Thermal Energy = m C (T(2) - T(1))

1. (2 pts.) A 200-Watt light bulb is on for 30 hours. How much electrical energy is consumed? Express your answer in units of kilowatt-hours. (A kilowatt is 1000 watts.)

2. (3 pts.) A resistor is dropped in a thermos of water. The resistor is 1 ohm, and a voltage of 4 V is applied for 20 minutes (1200 seconds). How much energy is dissipated in the resistor (Units!)?

Important Disclaimers and Caveats

Go back to the Chicago Fall 1993 Energy home page.