Physics G485 Definitions

Front 1

Electric field strength

Back 1

E, defined as force per unit positive charge

Front 2

Magnetic flux density

Back 2

B, defined by F = BILsintheta, F is force on a wire of length L carrying a current I at an angle theta to the field

Front 3

One tesla

Back 3

T, is the magnetic flux density when a wire of length one metre and carrying a current of one ampere at a right angle to the field experiences a force of one newton

Front 4

Magnetic flux through an area A

Back 4

defined as the product of the magnetic flux density B and the projection of area A onto a surface at right angles to the flux. phi = BAcostheta where theta is the angle between the plane of the area and the projection surface

Front 5

One weber

Back 5

is the magnetic flux when a magnetic field of magnetic flux density one tesla passes at right angles through an area of one square metre

Front 6

Magnetic flux linkage

Back 6

for a coil equals the magnetic flux through the coil multiplied by the number of turns on the coil

Front 7

Faraday's law of em induction

Back 7

states that the magnitude of the induced e.m.f is equal to the rate at which magnetic flux is cut

Front 8

Len'z law

Back 8

states that the direction of any induced current is in a direction that opposes the flux change that causes it

Front 9

Capacitance

Back 9

defined as the charge stored per unit p.d

Front 10

Farad

Back 10

Capacitance of one coulomb per volt

Front 11

The time constant

Back 11

of a circuit containing a capacitor of capacitance C and a resistor of resistance R is given by T = CR

Front 12

The nucleon number A

Back 12

is the number of nucleons in any nucleus

Front 13

The proton number Z

Back 13

is the number of protons in a nucleus

Front 14

Isotopes

Back 14

Two nuclides with the same number of protons but different numbers of neutrons

Front 15

Activity

Back 15

The rate at which a source emits radioactive particles

Front 16

The decay constant

Back 16

relates activity A to the number of nuclei N by the equation A = lambdaN

Front 17

The half-life

Back 17

of a radioactive source is the time taken for the activity of the source to decrease by one half. It is also the time taken for the number of radioactive nuclei to decrease by one half

Front 18

Binding energy

Back 18

is the energy required to separate an atom into its constituent parts

Front 19

Intensity

Back 19

l of a beam of X-Rays is defined as the power per unit cross-sectional area

Front 20

Larmor Frequency

Back 20

Frequency of precession