Force fields, Electric currents, magnetic fields, and GPE

Question 1

What is electrical kinetic energy?

Answer 1

Electrical kinetic energy is the energy due to moving charges.

Question 2

When is electrical kinetic energy larger?

Answer 2

When the electric current is larger.

Question 3

What is electric current?

Answer 3

Electric current is the flow of electric charge.

Question 4

What is the unit and symbol of electric current?

Answer 4

1. Unit of electric current: Amps (A)

2. Symbol for electric current I

Question 5

Electric current is larger when:

Answer 5

1. More charges are moving

2. Charges are moving faster

Question 6

Electric circuit:

Answer 6

An electric circuit is a loop of wire where charges are raised to a high electrical potential energy by a battery or a generator, and allowed to flow through the circuit back to where they started to reach a more stable state.

Question 7

Electric Circuits must have:

Answer 7

1. A circular path (a loop of wire)

2. Something to increase the potential energy (battery or generator)

Question 8

Relationship between electric currents and magnetic fields (3)

Answer 8

1. ALL electric currents produce magnetic fields.
2. Larger electric currents and more electric currents produce a stronger magnetic field.
3. Changing the direction of the electric current changes the direction of the magnetic field.

Question 9

Relationship between changing magnetic fields and electric currents:

Answer 9

Changing magnetic fields produce electric currents. A magnetic field can be changed by changing the strength of the field or the direction of the field.

Question 10

Motors

Answer 10

In a motor, an electric current produces a magnetic field which puts a force on the magnet, making the motor turn.

Question 11

Generators

Answer 11

In a generator, a loop of wire is turned in a magnetic field. When the loop turns, the magnetic field changes, producing an electric current in the loop.

Question 12

What is a force field?

Answer 12

A force field is a model that shows how the direction and strength of a non-contact force changes in the region of space.

Question 13

The direction of the force in force fields:

Answer 13

In a field, the direction of a force is shown by the direction of the field lines.

Question 14

The magnitude of the force in force fields:

Answer 14

The magnitude of the force is shown by the distance between the field lines.

1. The closer the field lines the stronger the force
2. The further apart the field lines the weaker the force

Question 15

Gravitational field

Answer 15

In a gravitational field, the field lines point in the direction that a mass feels a gravitational force. The closer the field lines are together the stronger the gravitational force on any mass.

Question 16

Field lines never

Answer 16

1. Touch

2. Cross

Question 17

Electric field- positive charges

Answer 17

In an electric field, the field lines point in the same direction that a positive charge feels an electrostatic force

Question 18

Electric field-negative charges

Answer 18

In an electric field, the field lines point in the opposite direction that a negative charge feels an electrostatic force.

Question 19

Magnetic field-North poles

Answer 19

In a magnetic field, the field lines point in the same direction that a North pole feels a magnetic force.

Question 20

Magnetic field- South poles

Answer 20

In a magnetic field, the field lines point in the opposite direction that a South pole feels a magnetic force.

Question 21

Energy in fields (3)

Answer 21

1. When an object in a field changes position its potential energy changes.
2. If an object moves against the force its potential energy increases
3. If the object moves with the force its potential energy decreases.

Question 22

Gravitational potential energy equation

Answer 22

GPE=mgh

• m is mass (kg)
• g is acceleration due to gravity (m/s^2) (9.8m/s^2)
• h is height (m)

Question 23

Acceleration

Answer 23

Acceleration is the measure of the change in linear kinetic motion; the change in speed divided by the time it took to change the speed.

Question 24

objects have the…..

Answer 24

same downward acceleration due to gravity, even if they have different masses.