Static Electricity
Circuits!
Circuits again
Variables
Electromagnetism
100
If an atom loses electrons, it becomes ...
Positively charged
100
How many paths through which charge can flow would be shown in a circuit diagram of a series circuit?
One path
100
Electrical resistance is measured in ...
ohms
100
When resistors are put in series next to each other, the equivalent resistance ...
Increases (In series, RT = R1 + R2 ...)
100
Electric field lines should be drawn from __ to __.
North to South
200
What is the SI unit of electric charge?
coulomb (C)
200
How many paths through which charge can flow would be shown in a circuit diagram of a parallel circuit?
At least 2
200
Electric current is the flow of
electrons
200
What is Ohm's Law? When can you use it?
V = IR
Can be used when 2 values are known (ex: if R and V are known, you can solve for I)
200
Iron filings are placed near a coil of copper wire. Which of the following will most likely cause the iron filings to move?
A. heating the copper wire until it emits light
B. making smaller turns in the copper wire coil
C. sending an electric current through the copper wire
D. increasing the number of turns in the copper wire coil
C. sending an electric current through the copper wire
300
Two particles with the same positive charge are 100 cm apart. What happens to the electric force between the two particles when the charge on each particle doubles?
A. The electric force becomes attractive.
B. The magnitude of the electric force decreases.
C. The attractive electric force becomes two times as strong.
D. The repulsive electric force becomes four times as strong.
D. The repulsive electric force becomes four times as strong.
300
What is the equivalent resistance in this circuit?
What is the current traveling through this circuit?
What is the voltage drop across R2?
450 ohm
0.02 amperes
6 volts
300
Describe the circuit elements included in this diagram. Is this an open or closed circuit?
battery, lightbulb, switch
open circuit
300
When resistors are added in parallel, the equivalent resistance in the circuit ...
decreases
300
Which of the following describes how a generator operates?
A. It creates a large resistance to oppose the flow of electricity.
B. It rotates a coil of wire through a magnetic field to produce a current.
C. It uses side-by-side coils of wire to transform a voltage to a safe level.
D. It transmits a signal to a circuit breaker to protect its components.
B. It rotates a coil of wire through a magnetic field to produce a current.
400
What is the primary difference between insulators and conductors?
A. Electrons are present in insulators but not in conductors.
B. Electrons are present in conductors but not in insulators.
C. Electrons are free to move in insulators but not in conductors.
D. Electrons are free to move in conductors but not in insulators.
D. Electrons are free to move in conductors but not in insulators.
400
What is the voltage across the terminals of a 35 Ohm resistor that has 0.088 A of current flowing through it?
3.08 volts
400
What is the current in the circuit?
3 amperes
400
A simple circuit is made using a battery, a light bulb, and some wire. Based on Ohm’s law, which of the following should always decrease the brightness of the light bulb?
A. using less wire in the circuit
B. adding a second bulb in series
C. adding a second bulb in parallel
D. using a battery with a greater voltage
B. adding a second bulb in series
400
Which statement describes what most likely occurs when a magnetic compass is placed next to a simple circuit made from a battery, a light bulb, and a wire?
A. A magnetic field created by the compass causes the light bulb to stop working.
B. A magnetic field created by the electric current causes the compass needle to move.
C. A magnetic field created by the compass increases the current in the electrical circuit.
D. A magnetic field created by the electric current places negative charges on the compass.
B. A magnetic field created by the electric current causes the compass needle to move.
500
Which of the following sets of charges has the greatest attractive force when the charges are equal in magnitude?
A. two like charges placed 1 m apart
B. two like charges placed 2 m apart
C. two opposite charges placed 1 m apart
D. two opposite charges placed 2 m apart
C. two opposite charges placed 1 m apart
500
What is the voltage drop across R2?
What is the current across R2?
9 volts
0.2 amperes
500
In order for current to flow in a circuit, you must have ...
(identify BOTH requirements)
1) voltage source
2) a closed loop / path for electrons to travel
500
A series circuit is constructed with a battery, a light bulb, and a resistor. What happens if the resistor is removed from the circuit?
A. The current increases and the bulb’s light becomes dimmer.
B. The current increases and the bulb’s light becomes brighter.
C. The current decreases and the bulb’s light becomes dimmer.
D. The current decreases and the bulb’s light becomes brighter.
B. The current increases and the bulb’s light becomes brighter.
500
Draw the electric field lines that would exist between two magnets, arranged |N S| |S N|
Will be drawn on board