Definitions Unit 2

Question 1

Field of Force

Answer 1

A region of space within which objects with a particular property experience a force

Question 2

Gravitational Field

Answer 2

A region of space within which a mass will experience a force

Question 3

Electric Field

Answer 3

A region of space within which a charge will experience a force

Question 4

Magnetic Field

Answer 4

A region of space within which a moving charge will experience a force

Question 5

Gravitational Field Strength

Answer 5

The gravitational field strength, g, at a point is equal to the force experienced per unit mass, in N kg^-1

Question 6

Newton’s Law of Universal Gravitation

Answer 6

‘Between any 2-point masses there exists an attractive force which is directly proportional to the product of the masses, and inversely proportional to the square of their separation

Question 7

Kepler’s 3rd Law

Answer 7

‘The square of their period of revolution, T, is directly proportional to the cube of their mean distances, r, from it

Question 8

Electric Field Strength

Answer 8

Electric field strength, E, at a point is the force experienced per unit positive charge at that point

Question 9

Coulombs Law

Answer 9

Between every 2 point charges there exists an electrical force which is directly proportional to the charge of each and inversely proportional to the square of their separation.

Question 10

Capacitance

Answer 10

The charge stored per unit volt, C = Q/V

Question 11

Farad

Answer 11

One farad can be described as the capacitance which stores a one-coulomb charge across p.d of one volt.

Question 12

Time Constant

Answer 12

The time taken for the p.d / Q / I to fall to 1/e of its initial value while a capacitor discharges

Question 13

Magnetic Flux Density, B

Answer 13

The force per unit current carrying length

Question 14

Tesla

Answer 14

One Tesla is the magnetic flux which will cause a conducter 1m long, carrying a current of 1A, at right angles to the field, to experience a force of 1N.

Question 15

Faraday’s Law

Answer 15

Induced EMF is directly proportional to the rate of change of flux linkage

Question 16

Lenz’s Law

Answer 16

The direction of the induced current is such that it opposes the change in magnetic flux that is producing it

Question 17

Quantisation of Charge

Answer 17

All electric charges are an integral multiple of a fixed charge, which is the value e = 1.6 x 10^-19C

Question 18

Specific Charge

Answer 18

The ratio of the charge of a particle to its mass, q/m

Question 19

Anti-particle / Anti-matter

Answer 19

Identical particle with same mass but with opposite charge

Question 20

Fundamental Particles]

Answer 20

A particle with no internal structure that cannot be subdivided into smaller particles.