A2 Physics 2 1,2,3

Question 1

Electric field strength

Answer 1

force of attraction per unit charge

Question 2

Fleming’s left hand rule

Answer 2

The rule used to predict the direction of the force experienced by a current carrying conductor placed in an external magnetic field, T-motion, FF- field, SF- current

Question 3

Magnetic flux density

Answer 3

B, the strength of a magnetic field. Defined a F/IL where F is the forced on a conductor of length L in the field carrying a current I at right angles to the magnetic field.

Question 4

Tesla

Answer 4

The strength of a magnetic field that will produce a force of 1n on a current of 1A in a wire of 1m at right angles to the magnetic field

Question 5

Magnetic flux

Answer 5

The product of magnetic flux density normal to the circuit and the cross-sectional area of the circuit

Question 6

Weber

Answer 6

The magnetic flux of a field of strength 1 Tesla through a circuit of area 1m^2

Question 7

Magnetic flux linkage

Answer 7

The product magnetic flux and the number of turns on a coil

Question 8

Faraday’s law of electromagnetic induction

Answer 8

The induced emf in a circuit loop equals the rate of change of magnetic flux linkage

Question 9

Lenz’s Law

Answer 9

The induced emf is in a direction which opposes the change producing it

Question 10

Capacitance

Answer 10

The ratio of charge stored to the p.d across the plates of a capacitor

Question 11

Farad

Answer 11

The capacitance of a pair of plates that can store 1 coulomb of charge for every 1V of p.d

Question 12

Time constant

Answer 12

the time taken for the current, charge, and p.d for a capacitor to fall to 1/e of its original value when discharging through a resistor

Question 13

proton number

Answer 13

the number of protons in the nucleus of an atom

Question 14

Nucleon number

Answer 14

The sum of the number of protons and the number of neutrons in the nucleus of an atom

Question 15

Isotope

Answer 15

Atoms of the same element with the same number of protons but a different number of neutrons

Question 16

quantities conserved in nuclear decay

Answer 16

Proton number, Nucleon number, Mass- energy

Question 17

Activity

Answer 17

The rate of decay of a nuclei in a radioactive sample

Question 18

Decay constant

Answer 18

The probability that any particular atom of an isotope will decay per unit time

Question 19

Half-life

Answer 19

The mean time taken for half the number of active nuclei in a radioactive sample to decay

Question 20

Binding energy

Answer 20

The minimum external energy required to separate all the protons and neutrons in a nucleus

Question 21

Binding energy per nucleon

Answer 21

The minimum external energy per nucleon required to separate all the protons and neutrons in a nucleus

Question 22

Intensity

Answer 22

Power per unit cross-sectional area

Question 23

Parsec

Answer 23

The distance when the stellar parallax is 1 arc second

Question 24

Astronomical unit

Answer 24

The average distance from the earth and the sun

Question 25

Light year

Answer 25

The distance light travels in a year

Question 26

Obler’s paradox

Answer 26

For an infinite, static and uniform universe the night sky should be bright in all directions because of light received from stars

Question 27

Hubble’s Law

Answer 27

The recessional speed of distant galaxies is directly proportional to their distance from the obsever

Question 28

Cosmological principle

Answer 28

The universe is homogeneous and isotropic and the laws of physics are the same at all points within it

Question 29

Critical density

Answer 29

The density of the universe which would cause it to be flat, the rate of expansion would tend towards zero in infinite time