Second Semester Final Exam Study Guide Flashcards
What is electric force?
The attraction or repulsion between electric charges.
What is an electric field?
A region around a charged object where the electric force is exerted. The closer the field lines, the stronger the force.
What is the difference between static and current electricity?
Static electricity is electricity that builds up on an object, but does not flow continuously. Current electricity is moving electrons (flowing).
How is current related to resistance?
The higher the resistance, the lower the current flow.
List the three basic features of an electrical circuit.
- Conducting path
- Power source
- Electrical device (load, resistor)
What does Ohm’s Law state?
Resistance = Voltage/Current
Voltage = Current x Resistance
Current = Voltage/Resistance
These three factors will affect how a current moves through a circuit.
List the four factors that affect resistance. Describe how they affect resistance.
- Material - Conductors have low resistance and insulators have high resistance.
- Length - Longer wires have more resistance than shorter wires.
- Diameter - Larger diameter wires have lower resistance compared to smaller diameter wires.
- Temperature - Higher temperatures increase the resistance and cooler temperatures decrease the resistance.
What units are used to measure voltage, resistance, and current?
- Voltage = Volts (V)
- Resistance = Ohms (ῼ)
- Current = Amperes (A)
What is the rule for the interaction of magnetic poles and electric charges?
Opposite poles/charges attract and similar poles/charges repel
List three insulators and three conductors of electricity.
Insulators - wood, plastic, glass
Conductors - vinegar, salt water, tap water
Describe how electric charges can be transferred by induction.
During induction, charges are separated by an electric field. When a charged object is brought near a neutral object the electric force within the field will separate positive and negative charges in the object (charging it).
Describe what happens to the current and resistance in a series circuit when more devices are added and the voltage remains constant?
If voltage remains constant and more devices are added, the resistance of the circuit will increase and the current will decrease.
Describe what happens to the current and resistance in a parallel circuit when more devices are added and the voltage remains constant?
If voltage remains constant and more devices are added in parallel, then the overall resistance decreases and the current increases.
A battery converts ________ energy into __________ energy.
Chemical, electrical
What is voltage and how does it relate to current?
Voltage is the difference in electrical potential energy between two places in a circuit. Voltage can be thought of as the force pushing an electric current. The greater the voltage (difference in positive and negative) the greater the current can be.
