knowledge

Question 1

pressure law

Answer 1

p/T constant at V constant

Question 2

Charle’s law

Answer 2

v/T constant at p constant

Question 3

Boyle’s law

Answer 3

pV constant at T constant

Question 4

real gas approximates to ideal gas at

Answer 4

low pressure and high temperature (also low density)

Question 5

ideal gas assumptions

Answer 5

no intermolecular forces, elastic collisions between the molecules, molecules are treaded as points, there is no time spent in the collisions, molecules are monoatomic

Question 6

electromagnetic spectrum from lowest frequency to the highest

Answer 6

radio waves, microwaves, infra-red waves, visible light, UV, X-rays, gamma rays

Question 7

wavelengths of visible light

Answer 7

400- 750 nm

Question 8

frequencies of visible light

Answer 8

400-800* 10^12 Hz

Question 9

total internal reflection

Answer 9

there is no refraction, only reflection

Question 10

standing waves

Answer 10

interference of two waves traveling in the opposite directions with the same amplitudes and same frequencies,

Question 11

intensity of standing wave

Answer 11

maximum-antinode, minimum-node

Question 12

potential divider

Answer 12

used to produce variable power supply

Question 13

sensors

Answer 13

more light/temperature- lower potential difference across the sensors

Question 14

primary cell

Answer 14

non-rechargeable (alkaline batteries)

Question 15

secondary cell

Answer 15

rechargeable (lid-acid car battery)

Question 16

alpha radiation

Answer 16

low penetrability, paper to absorb it

Question 17

beta radiation

Answer 17

medium penetrability, a few mm of aluminum to absorb it

Question 18

gamma radiation

Answer 18

high penetrability, 10 cm of lead to absorb it

Question 19

Rutherford scattering

Answer 19

evidence of existence of a nucleus

Question 20

emission and absorption spectra

Answer 20

evidence of electron energy levels

Question 21

structure of matter

Answer 21

hadrons, leptons, exchange particles

Question 22

hadrons

Answer 22

baryons- 3 quarks, mesons- 1 quark and 1 antiquark

Question 23

quark confinement

Answer 23

isolated quarks and gluons cannot exist

Question 24

function of moderator

Answer 24

slows down neutrons to increase the probability of them interacting in further reactions

Question 25

function of control rods

Answer 25

control the chain reaction by absorbing neutrons

Question 26

function of heat exchanger

Answer 26

allows nuclear reaction to be sealed off from the rest of the environment

Question 27

thermal energy transfers

Answer 27

conduction, convection, radiation, (evaporation)

Question 28

Wien's law

Answer 28

The higher the temperature of the body, the lower the maximum wavelength and higher the intensity of emitted light.

Question 29

greenhouse gases

Answer 29

methane, water vapour, carbon dioxide, nitrous oxide

Question 30

SHM spring assumptions

Answer 30

friction is negligible, mass of the spring is negligible compared to mass of the load, g is constant

Question 31

SHM pendulum assumptions

Answer 31

air fricition is negligible, mass of the string is negligible compared to mass of the load, maximum angle of swing is smaller than 5 degrees

Question 32

adding more slits to multiple slit diffraction causes

Answer 32

more intense primary maxima, narrower primary maxima, secondary maxima less significant

Question 33

thin-film interference

Answer 33

v1>v2- reflection out of phase (+π), transmitted in phase

Question 34

red shift

Answer 34

source moving away from the observer, decreased frequency

Question 35

blue shift

Answer 35

source moving towards the observer, increased frequency

Question 36

charge on a hollow conducting sphere

Answer 36

charge uniformly distributed on the outside of the sphere, no charge on the inside of the sphere, hence zero electric field inside, and constant electric potential

Question 37

gravitational field inside the hollow object

Answer 37

zero, as per Newton's shell theorem, constant gravitational potential

Question 38

step-up transformer

Answer 38

increases voltage and decreases current, good for transmission of electric power to avoid large losses of power

Question 39

step-down transformer

Answer 39

decreases voltage and increases current, protection of end-users, high voltage is dangerous

Question 40

losses in the transformer

Answer 40

resistance of the winding (heat), eddy currents in the core, flux losses (flux not going through the secondary coil)

Question 41

increasing efficiency of a transformer

Answer 41

core with high permeability, laminating core

Question 42

rectification of AC to DC

Answer 42

single diode- half rectification | diode bridge- full-wave rectification

Question 43

smoothened rectification

Answer 43

capacitor (current still fluctuates but less-output ripple, time constant of the capacitor must be large enough)

Question 44

influence of light over photoelectric effect

Answer 44

number of electrons emitted depends on the intensity of light (number of photons), energy of electrons depends on the frequency of the light

Question 45

Davisson and Geimer experiment

Answer 45

electron diffraction, evidence of their wave-like properties

Question 46

hydrogen emission spectrum

Answer 46

``` Lyman series (n=1)- UV Balmer series (n=2)- visible light Paschen series (n=3)- IR ```

Question 47

Bohr atom model assumptions

Answer 47

quantised angular momentum, quantised energy

Question 48

Schrodinger model of atom

Answer 48

describes positions of electrons by probability density functions

Question 49

estimates from Heisenberg uncertainty principle

Answer 49

energy of electron in an atom, impossibility of electron to exist within a nucleus of atom, lifetime of an electron in an excited state

Question 50

white light incident on diffraction grating

Answer 50

white center of diffraction pattern, closeness of colours to centre by decreasing vawelength (lowest wavelength is closest), greater the order the wider the pattern, gaps between first-order and second-order spectra

Question 51

gravitational potential due to multiple objects

Answer 51

sum of potentials due to each obejct

Question 52

pair production condition

Answer 52

photon with large enough energy must interact with nucleus (nucleus conserves momentum)

Question 53

electron's path in a non-parallel electric field

Answer 53

parabolic path

Question 54

total energy of orbiting satellite

Answer 54

negative

Question 55

reasons for establishment of the standard model

Answer 55

incorporates strong and weak nuclear forces between nucleons, explains decay of neutron to proton, incorporates conservation rules

Question 56

measuring half-life

Answer 56

Geiger counter