2020 Paper 1 Flashcards
(9 cards)
Explain why a torch would not work if you place the cells in the wrong way around (torch contains one LED, one switch and 3 cells)
-there is no current in a diode in the reverse direction
-because a diode has a very high resistance (in reverse direction)
List (3) man-made sources of background radiation
-radioactive waste from nuclear power stations
-radiotherapy
-(medical) x-rays
-nuclear weapon testing
-named nuclear disaster (chernobyl/fukushima)
name 2 nuclear fuels
uranium/plutonium
Describe the process of nuclear fission inside a nuclear reactor [4]
-neutron absorbed by a uranium nucleus
-nucleus splits into 2 parts
-(2/3) neutrons are released
-and gamma rays are emitted
Explain how the process or nuclear fusion leads to the release or energy [2]
-lighter nuclei join to form heavier nuclei
-some of the mass (of nuclei) is converted to energy (as radiation)
At the bottom of the slide, all riders (of different masses) and their sleds have approximately the same speed.
Explain why. [4]
-the decrease in gravitational potential energy = the increase in kinetic energy
(so 1/2mv2=mgh)
-masses cancel on both sides
(so v2=2gh)
-speed only depends on vertical height (and grav field strength)
-variation will be due to air resistance/friction
what do precise results show
-little variation
-smaller range
Explain why adding resistors in parallel decreases the total resistance
-multiple paths for charge/(current)/electrons to flow
-total current is greator for the same potential difference when more resistors are added
If the temp of a balloon is increased but the mass and volume remain constant, explain why the pressure extered by the gas inside the balloon would increase [4]
-particles would have a higher kinetic energy
-so increased number of collisions with the walls of the balloon per second
-greater forces exerted in collisions (between walls & particles)
-greater forces exerted exerted on same area (link to p=F/A)
