Field Forces Study Guide

Are electric charges conserved?

electric charge is conserved

Attracting forces have what kind of sings?

opposite charges attract. like charges repel

Can electric field lines form closed loops?

Electric field lines never form closed loops; conservative

Can you have a repulsive force when it comes to gravitation?

Gravitation is attractive, electric forces are repulsive

Like charges do what?

Like charges repel each other

Charging by bringing a charged conductor near another charged object and then grounding the conductor is called what?

induction

Charging by contacting a charged object with a neutral object is called?

conduction

Do electric field lines ever cross each other?

electric field lines cannot cross

Do protons and neutrons attract or repel?

attract

Electric field strength depends on what?

charge and distance

If an object becomes positively charged the other object it was in contact with becomes what?

negatively charged (gains electrons)

If charge is tripled for both point charges how does that affect the electric force between two point charges?

electric forces if 9X

If distance between two objects goes from 20 m to 10 m how does that affect the gravitational force between the objects?

gravitational force increases (gravitational force is inversely proportional to the square of the separation distance between the two interacting objects)

If distance is tripled how does that affect the gravitational force between two objects?

gravitational attraction is decreased by a factor of 9

If two point charges are 3 m apart and are moved to a distance of 15 m apart what factor does the electric force between them change?

idk

Is the electric force between charges stronger when they are close together or far apart?

close together

Repelling forces have what kind of signs?

unlike charges

Removing the excess charge on an object by means of the transfer of electrons between it and another object of substantial size is called?

grounding

The force that the Earth exerts on the moon is \_____ compared to the force that the moon exerts on Earth.

equal

The gravitational force that Earth exerts on an object is called what?

weight

What happens when a glass rod is rubbed with silk?

rod becomes positively charged (electrons are removed from the rod), silk becomes negatively charged

What is it called when the opposite charges separate within an object?

polarization

What is the charge of an electron?

negative charge

What relationship does the distance between two objects have to the gravitational force between them?

inversely proportional to the square of the distance between the two objects.

What relationship does the mass of an object have to the gravitational force between two objects?

directly proportional to the masses of the two objects

What types of materials are electric charges easily transferred in?

conductors (metals)

When the distance between two charges is halved, the electrical force between the charges?

the force between the two charges is quadrupled

Where do you measure distance from when looking at the gravitational force between objects?

measure from centers

Why does an astronaut weigh less on the moon than on Earth?

less gravitational strength on the moon than Earth

What happens when you have like poles in a magnet?

repel each other

Where is the magnetic field around a permanent magnet greatest?

greatest at poles

In a magnetized object, how are the domains arranged?

same direction (magnetized)

All magnetism is created by what source?

motion of electric charges

What surrounds moving electrons?

an electric field and a magnetic field

If you put a north pole and a south pole together what will happen?

pull together (attract)

What happens when you break a bar magnet in half?

If you break a bar magnet in half, each half results in a smaller bar magnet with north and south ends.

Is the magnetic field strong when it is close to or far away from a magnet?

closer, stronger

What are magnetic domains?

magnetic fields of atoms are grouped together and aligned.

How are magnetic field lines drawn?

Magnetic field lines can be drawn by moving a small compass from point to point around a magnet.

How can electric current be induced in a wire?

moving a magnet up and down near the wire

What is electromagnetic induction?

The phenomenon of inducing voltage by changing the magnetic field around a conductor

What is the left hand rule?

find the direction of force/motion of the conductor in an electric motor when the magnetic field direction and the current direction are known.

What is the right hand rule?

The same thing as left hand rule just with right hand and works best with electric generators.

What is the difference between electric generators and electric motors?

An electric motor converts electricity into mechanical energy, providing a power source for machinery. A generator does the opposite of this, converting mechanical energy into electricity.

According to Newton's laws, a rock and a pebble will fall with the same acceleration in a gravitational field because the gravitational force on each is what?

different, ratio of mass the same