# Shared Flashcard Set

## Details

physics 121
final exam
10
Physics
12/13/2009

Term
 Current is a measure of
Definition
 the amount of charge that moves past a pount per unit time   i=dQ/dt
Term
 The current is "0" in a conductor when no potiential difference is applied becasue
Definition
 for every electron with a given velocity there is another with a velocity of equal magnitude and opp direction
Term
 if the potiential difference across a resistor is doubled   ΔV=iR
Definition
 then only the current is doubled
Term
 a current of .05 ampere exsist in a 60-ohm lamp. the applied potiential difference is:
Definition
 ΔV=ir=.5 X 60=30V
Term
 Four 20Ω resistors are connected in parallel and the combination is connected to a 20-V emf device. the current in the device is:
Definition
 i=E/Req    20/5=4A
Term
 A battery with an emf of 12V and an internal resistance of 1 Ω is used to charge a battery with an emf of 10V and an internal resistance of 1Ω. The current in the circuit is:
Definition
 1A
Term
 A 120-V power line is proected by a 15-A fuse. what is the maximum number of 120V, 500W light bulbs than can be operated at full brightness from this line?
Definition
 3
Term
 A 2Ω resistor and a 4Ω resistor are connected in parallel at a 6V battery. The rate of energy dissipated by the 2Ω resistor is:
Definition
 P=v^2/R      18W
Supporting users have an ad free experience!