2023 Past Paper (Higher) Flashcards
Transformer X causes the potential difference to increase & causes the current to___
decrease
Which equation links current (I), power (P) and resistance (R)?
P = I^2 * R
Write down the equation which links efficiency, total energy input and
useful energy output.
efficiency =
useful energy output/
total energy input
Before the power supply was switched on, the thermometer was used to measure the
temperature of the iron block.
The student left the thermometer in the iron block for a few minutes before recording
the initial temperature.
Suggest why
so the thermometer temperature
was the same as the
temperature of the iron block
The student repeated the investigation but wrapped insulation around the iron block.
What effect will adding insulation have had on the investigation?
the calculated specific heat
capacity will be more accurate
the iron block will transfer
thermal energy to the
surroundings at a lower rate
What is meant by ‘direct potential difference’?
polarity of the potential
difference doesn’t change
Which equation links charge flow (Q), energy (E) and potential difference (V)?
E = QV
(6) The electrical circuit was left switched on while the ice changed from a solid to a liquid
and increased in temperature to 5 °C.
Explain the changes in the arrangement and movement of the particles as the ice
melted and the temperature increased to 5 °C
- particles in a solid are in a regular pattern
- particles in a liquid are in a random arrangement
- particles in a solid are vibrating about fixed positions
- particles in a liquid are moving freely
- as the ice changes to water the temperature remains constant
- because as the ice changes to water the potential energy of the
particles increases - as the water warms the particles move faster
- so the kinetic energy of the particles increases
- internal energy is the total kinetic and potential energy of all the
particles
A solar power system is installed in the remote village in addition to the
hydroelectric generator.
Explain why this improves the reliability of the electricity supply to the village.
in the summer the power output
from the hydroelectric generator
is lower but the solar power
output would be greater
so less variation in total power
output (which improves the
reliability of the supply)
Compare the structure of an atom of carbon-14 with the structure of an atom of
carbon-12.
- same number of protons
- same number of electrons
- different number of neutrons
What does ‘a half-life of 5700 years’ mean?
the time it takes for the number of nuclei (in a radioactive
sample) to halve
Explain which isotope would cause the biggest risk to a person’s health based only on
the half-life of each isotope.
(N-18 has smallest half life)
nitrogen-18
greatest activity
(so) greatest dose of radiation
absorbed (per second)
Describe the difference between irradiation and contamination.
irradiation is the exposure of an
object / person to radiation
contamination is the
(unwanted) presence of
radioactive material / atoms on
an object / person
Give one health risk to a person working close to a source of nuclear radiation.
- cancer / tumours
- DNA / genetic mutation
- damages / kills cells
- radiation poisoning / sickness
Explain why the worker needs to stand close to the radiation detector.
some radioactive materials emit
alpha radiation
which has a (very) short range
