Physical Science 1119 Test
_____ is the science of current electricity.
Electrodynamics
______ is the science of static electricity.
Electrostatics
______ and ______ cannot be produced by electricity unless there is some resistance present.
Heat...light
What current does the parallel circuit in (47) draw?
I=E/R
What current flows in the circuit if it is connected to a 30v battery and contains a resistor of 20?
I=E/R
What is the resistance of a lamp that is connected to 120 volt circuit and draws 1.5 A of current?
I=E/R
What is the voltage of the power source if a motor with a resistance of 20 draws a current of 1.5 A?
I=E/R
What watt light bulb uses .625 A of current when connected to a 120v circuit?
P=EI
_____ electricity is stationary electricity.
Static
conductor
allows free passage of electricity
current flow
ampere
armature
an electromagnet in a motor
The ______, _____, and ______ are the three components of a dry cell.
anode...cathode...electrolyte
resistance
anything that restricts current flow
In order for current to flow, a circuit must be ______.
closed
The law of conservation of electric charge states that the total electrostatic charge in the universe is _____.
constant
electrostatic force
coulomb
Connecting additional series cells increases the _____ and the _____.
current....emf
Current produced by an electrochemical cell is _____ current; house current is ____ current.
direct...alternating
Ohm's law states that electric current is _____ proportional to emf and _____ proportional to resistance.
directly....inversely
insulator
does not conduct electricity easily
Zinc, which easily _____ electrons, and copper, which readily _____ them, form an electrochemical cell when placed together.
donates.... accepts
The continuous movement of _____ causes electric current.
electrons
Connecting additional parallel loads in a circuit produces no change in the _____ decreases the ____, and increases the _____.
emf...resistance...current
capacitance
farad
emf
force that causes current flow
Because the charge is insulated by the ______, a Leyden jar can retain a charge for a long period of time.
glass
resistor
increases the resistance of circuit
cathode
negative pole of an electrochemical cell
Because electrons have a _____ charge, a deficit of electrons produces a ______ charge.
negative... positive
The law of electrostatic attraction and repulsion states that: a) any charge attracts a ____ object b) objects with like charges ______ each other c) objects with unlike charges _____ each other
neutral....repel...attract
semiconductor
normally an insulator, but may become a conductor
resistance
ohm
In a _____ circuit, the total resistance is always lower than the lowest resistance.
parallel
In a ______ circuit, the current may follow one of several paths.
parallel
anode
positive pole of an electrochemical cell
electrochemical cell
produces electric current by chemical interaction
Connecting an additional load increases the resistance in a ______ circuit.
series
In a _____ circuit, the current follow a single path.
series
A _____ transformer increases amperage and decreases voltage.
step-down
A _____ transformer increases voltage and decreases amperage.
step-up
superconductor
today functions only at very low temperatures
battery
two or more connected electrochemical cells
emf
volt
electric power
watt
A parallel circuit contains four 1.5v batteries and three resistances of 5.0, 2.5, and 4.0. what is the total emf?
1.5 v
What is the total resistance of the circuit in (47)?
1/Rt=1/R1 + 1/R2 + 1/R3
_____ current is current that changes direction.
Alternating
_______ electricity is electricity in motion
Current
_____ current is current that flows only in one direction.
Direct
