Calculating Electricity

Electricity Introduction

By William Lovering

Multiple Choice

If an object has the same number of positive and negative charges, its electrical charge is...

• positive
• negative
• neutral or no charge
• opposite

Multiple Choice

Objects that have an electric charge exert a force on other charged objects around them. This force is called ______.

• electrical force

• static electricity

• electromagnetic force

• subatomic particle

Multiple Choice

Opposite charges

• attract

• repel

• become neutral

• do nothing

Multiple Choice

The accumulation of excess electric charge on an object is called

• Static electricity

• Electric discharge

• Resistance

• Current electricity

Multiple Choice

Which of the following statements is false about electric field lines

• electric field lines cannot cross
• electric field lines point away from positive charge
• electric field lines are always straight lines
• electric field lines show how a proton would move in an electric field

Multiple Choice

___ are good conductors because they have loose electrons.

• copper
• aluminum 
• metals
• all of the above

Multiple Choice

Which of the following is an example of a conductor?

• plastic

• copper

• glass

• rubber

Multiple Choice

Removing a static charge by providing a path to the ground is called __.

• electric transfer
• grounding
• switching
• seperation

Multiple Choice

Only the __ move to create unbalanced charges.

• Neutrons
• Protons
• Electrons
• Static Electricity

Multiple Choice

Walking across a carpet is an example of charge being transferred by

• friction.

• induction.

• contact.

Multiple Choice

What method of static charging is shown in this picture

• Polarization
• Friction
• Induction
• Conduction

Multiple Choice

One example of static electricity is...

• rain
• thunder
• lightning

Multiple Choice

Transferring a charge without touching is ___

• conduction
• induction
• grounding 
• Newtons 3rd law

Multiple Choice

Voltage is measured in __.

• volts.
• watts.
• coulombs. 

Multiple Choice

The movement of electrons from atom to atom in a line results in a flow of _____. 

• amperage.
• electric current.
• electromagnetic connectors. 

Multiple Choice

As the resistance of a circuit increases, the current will

• increase
• decrease
• stay the same

Multiple Choice

Resistance is

• Measured using an ammeter

• Units are 'volts'

• How difficult it is for electrons to move through an object

• The continuous movement of electrons in a wire

Multiple Choice

What size resistor would produce a 3 Amp current flow with a 12 Volt battery

• 1 Ohm
• 3 Ohms
• 4 Ohms
• 12 Ohms

Multiple Choice

What is current measured in?

• Ω (Ohms)
• V (Volts)
• A (Amps)
• W (Watts)

Multiple Choice

What is the Voltage of a circuit that has a resistance of 5 Ω and a current of 2 A?

• 25 V
• 10 V
• 2.5 V
• 0.4 V

Multiple Choice

Voltage divided by Resistance

(V / R)

• Current

• Power

• Ohms

• Watts

Multiple Choice

The power of an appliance is...

• the amount of voltage going through it 
• the amount of energy transferred per second
• the amount of charge that passes through per second

Multiple Choice

Electrical power can be calculated using

• Resistance x Voltage
• Voltage x Current 
• Voltage ÷ Current

Multiple Choice

The voltage supplied to a circuit is 17 V and the current running through is 10 A. What is the power generated?

• 170 W
• 170 A
• 1.7 V
• 1.7 W

Multiple Choice

Calculate the electric power of an electrical appliance in which 10 A of current is flowing through a resistor of 2 ohms.
 
Remember: V=IR and P=VI

• 80 W
• 200 W
• 2.5 A
• 22.5 KJ

Fill in the Blank

A microwave oven with a power rating of 1,200 W is being usedfor 0.25 h.  How much electri-cal energy is being used by the microwave?