random Qs

Question 1

how does the size of the nucleus affect the rate of fusion events

Answer 1

A larger nucleus means the charge will be greater, which means the force needed to bring the nuclei together is increased. So a larger nucleus requires a greater Ke for fusion therefore it decreases the rate of fusion

A larger nucleus also means a larger radius. So it requires a smaller Ke so the rate of fusion increases

Question 2

what does 1 electron volt mean

Answer 2

work done on an electron in accelerating it through a potential difference of one volt

Question 3

what is dielectric constant and an equation for it

Answer 3

the same as the relative permittivity

relative permittivity = charge stored with dielectric present/charge stored without dielectric

Question 4

explain how polar molecules in a dielectric cause a change in capacitance

Answer 4

electric fields exist between plates

polar molecules align with their positive side facing the negative plate

producing a counter electric field and therefore reduces the field between the plates

pd is reduced between the plates but the charge stays the same so the capacitance increase as C = Q/V

Question 5

what benefit does launching a satellite from the equator of Earth have compared to the North Pole, and why

Answer 5

less fuel is required to send into orbit as the initial speed is greatest due to the Earth’s rotation

Question 6

how is velocity incorporated into faradays law

Answer 6

F = N Δɸ/Δt = BLv

1 weber is = 1 volt second; because the unit of flux change per second (weber per second) is the same as the volt

the area swept out by the rod = Lv so the flux swept out per second is BLv

Question 7

what is molar mass equal to

Answer 7

the mass of substance / number of moles