Electricity and Circuits Review

Flashcards for exam review based on lecture notes.

What is the relationship described by Ohm's Law?

For a given resistance, current is directly proportional to voltage.

What is the formula for Ohm's Law?

V = I x R (Voltage = Current x Resistance)

What is electrostatic charge?

A buildup of electric charge on an object, typically caused by friction.

What happens during electron transfer?

Electrons move from one material to another when they come into contact, leaving one positively charged and the other negatively charged.

Give examples of electrical conductors.

Copper, silver, aluminum

Give examples of electrical insulators.

Rubber, glass, plastic

What is electrical current?

The flow of electric charge (usually electrons) in a circuit.

What unit is used to measure electrical current?

Amperes (A)

How is current measured?

With an ammeter, connected in series with the circuit.

What are the requirements for electric current to flow?

1. Source of Energy. 2. Closed Circuit. 3. Conducting Material.

Describe electron flow in a circuit.

Electrons move from the negative terminal to the positive terminal of the power source.

Describe conventional current flow.

Defined as flowing from the positive terminal to the negative terminal (opposite of electron flow).

In circuit diagrams, what symbol is used to represent a battery?

Line with short parallel lines of unequal length on one side of the line

In circuit diagrams, how is a resistor represented?

Rectangle or zigzag line

In circuit diagrams, what symbol represents a switch?

Line with a break

In circuit diagrams, what symbol represents a Bulb?

Circle with a cross

In circuit diagrams, how is an ammeter represented?

Circle with 'A'

In circuit diagrams, how is a voltmeter represented?

Circle with 'V'

In a series circuit, what is true about the current?

The current is the same through all components.

In a series circuit, what is true about the voltage?

Voltage is divided across components.

In a series circuit, how is total resistance calculated?

Total resistance is the sum of individual resistances.

In a parallel circuit, what is true about the current?

Current divides among branches.

In a parallel circuit, what is true about the voltage?

Voltage is the same across all branches.

In a parallel circuit, what is true of the total resistance?

Total resistance is less than the smallest individual resistance.

What is voltage?

The potential difference across two points in a circuit.

What unit is used to measure voltage?

Volts (V)

How is voltage measured?

With a voltmeter, connected in parallel to the circuit component.

What is resistance?

The opposition to the flow of current in a circuit.

What unit is used to measure resistance?

Ohms (Ω)

Ohm's Law Formula

V=I×R

How do you calculate current (I) using Ohm's Law?

I = V/R

How do you calculate resistance (R) using Ohm's Law?

R = V/I

What are Ohmic Conductors?

Follow Ohm's Law; resistance remains constant as voltage and current change (e.g., resistors).

What are Non-Ohmic Conductors?

Do not follow Ohm's Law; resistance changes with voltage or current (e.g., diodes, light bulbs).

In a graph showing the relationship between Voltage and Current, what does a straight line indicate?

Ohmic Conductor: Straight-line graph showing a linear relationship between voltage and current.

In a graph showing the relationship between Voltage and Current, what does a curved line indicate?

Non-Ohmic Conductor: Curved graph, indicating a non-linear relationship.