IB Physics Electric & Magnetic Fields

Flashcards on Electric and Magnetic Fields for IB Physics, covering electric charge, Millikan's oil drop experiment, static electricity, Coulomb's law, electric field strength, electric field lines, and magnetic fields.

The property of matter responsible for the electric force is called __.

Electric Charge

The unit of electric charge is the __, symbolized by C.

coulomb

Charge is a __ quantity.

scalar

Matter is made up of atoms containing negatively charged __, positively charged __, and neutral __.

electrons, protons, neutrons

Most everyday objects are electrically __ because they contain atoms with equal numbers of protons and electrons.

neutral (zero charge)

An object becomes charged when it obtains an excess of or .

protons, electrons

charges attract, while charges repel.

Opposite, like

The law of conservation of charge states that the total charge in an isolated system __.

remains constant

According to the work example, to achieve a final charge of +5.0 μC when two spheres are brought into contact, charges q = −2.0 µC and q = __ must be used.

+12.0 µC

In Millikan's Oil Drop Experiment, oil is used instead of water because it does not __ quickly.

evaporate

In Millikan's Oil Drop Experiment, the equation for electric force is F = __.

Eq

In Millikan's Oil Drop Experiment, the value of fundamental charge was determined to be __ C.

1.60 × 10−19

Name three methods by which electric charge can be transferred: charging by __, charging by __, charging by __.

friction, electrostatic induction, contact

When a cloth and rod are rubbed together, electrons are transferred from the rod to the cloth which causes the rod to become __ charged.

positively

Connecting a charged body to the earth allows it to __ until it has a potential of 0 V.

discharge

__ is the separation of charge caused by a nearby charged object without any physical contact.

Electrostatic induction

Charge can be transferred through __ when there is physical contact between two objects.

contact

Connecting the fuel tank to the Earth with a wire called the __ reduces risk of sparks when refueling airplanes.

bonding line

Coulomb's Law states that the electric force between two point charges is directly proportional to the of the charges and inversely proportional to the of their separation.

product, square

The electric force is calculated using the expression F = __.

k (q1q2/r2)

The Coulomb constant, k, is equal to ==========.

8.99 × 10^9 N m^2 C^–2

The permittivity of free space ε0 = __ C^2 N^–1 m^–2.

8.85 × 10^–12

Unlike gravitational forces, electric forces can be attractive or __.

repulsive

__ is the measure of how easy it is to generate an electric field in a certain material.

Permittivity

Relative permittivity is defined as the __ of the permittivity of a material to the permittivity of free space.

ratio

An __ is a region of space in which an electric charge experiences a force.

electric field

Electric field strength is defined as the per unit experienced by a small positive test charge placed at that point.

force, charge

Electric field strength can be calculated using the equation E = __.

F/q

Electric field strength is a __ quantity.

vector

The strength of an electric field due to a point charge __ with the square of the distance.

decreases

The magnitude of the electric field strength in a uniform field between two charged parallel plates is defined as E = __.

V/d

In an electric field, field lines are always directed from the charge to the charge.

positive, negative

In a uniform electric field, the field lines are __ spaced at all points.

equally

Around a point charge, electric field lines are always __ radially inwards or outwards.

directly

The electric field lines between two opposite charges are directed from the to the charge.

positive, negative

The spacing, or __, of field lines represents the strength of an electric field.

density

A __ field is represented by field lines which are closer together.

stronger

Lines in a radial field must be __ to any conducting surface.

perpendicular

A __ field is a region of space in which a magnetic pole will experience a force.

magnetic

A magnetic field is created either by moving electric or magnets.

charge, permanent

Magnetic flux density is measured in __ (T).

teslas

A magnetic field is created around a __-carrying wire due to the movement of electrons.

current

In a magnetic field, field lines are always directed from the pole to the pole.

north, south

Two poles attract each other and two poles repel each other.

opposite, like

In a uniform magnetic field, the strength of the magnetic field is the same at __ points.

all

On Earth, a magnetic compass will always point as it is attracted to the Earth's magnetic pole.

north, south

Magnetic field lines in a current-carrying wire are __ rings, centered on the wire.

circular

The direction of the magnetic field from current can be determined using the __ rule.

right-hand grip

The poles of a solenoid can be determined using the __ rule.

right-hand grip

In a solenoid, the pole forms at the end where the current flows anti-clockwise, and the pole at the anti-clockwise end.

north, south

A flat circular coil is equivalent to one of the coils of a __.

solenoid