Paper 1 Flashcards
(19 cards)
What is the relationship between a the resistance of a wire at constant temperature and its length?
Directly proportional
The student used a cell that had a potential difference of 1.50 V
Explain why the cell was not an electrical hazard to the student in the investigation
The cell was not an electrical hazard as
- low potential difference between earthed student and cell
- no electric shock
What is an electric field??
the region where another positively charged object experiences a force
How many micrometres is 1C?
1, 000, 000
When replaced, the cells were put into the torch the wrong way around.
Explain why the torch did not work
- there is not current in the diode in the revere direction
- diode has a very high resistance in the reverse direction
Why might wind power alone may not be enough to meet the power requirements for the town?
- unreliable no power when the wind stops
- impossible to increase supply when there’s extra demand
- has to be stopped if wind is too powerful
Give two environmental advantages of using a gas-fired power station to generate
electricity compared with using a coal-fired power station.
- less carbon dioxide so less global warming
- no sulfur dioxide released so no acid rain
Radioactive waste from nuclear power stations is box a man-made source of background radiation.
Give one other man-made source of background radiation.
- X-rays
- nuclear weapons testing
- nuclear disasters like Chernobyl
Describe the process of nuclear fission inside a nuclear reactor
- neutron absorbed by uranium nucleus
- nucleus splits into two parts
- 2 or 3 neutrons are released
- gamma rays are emitted
Explain how the process of nuclear fusion leads to the release of energy
- lighter nuclei join to form heavier
nuclei - some of the mass (of the nuclei)
is converted to energy (of
radiation)
Explain the advantage of the radioactive waste having a shorter half-life.
- activity decreases quickly
- risk of harm decreases quickly
At the bottom of the slide, all riders and their sleds have approximately the same speed.
- decrease in Ep = increase in Ek
- masses cancel on both sides of the equation
- final speed only depends on vertical height and GPE
- variations will be due to air resistance or different initial speed
An electrician replaced the switch.
The electrician would have received an electric shock unless the circuit was
disconnected from the mains supply.
Explain why.
- one wire in the switch is live
- the electrician is earther
- so there will be a large potential difference between the live wire and the electrician
The temperature of the helium in the balloon was increased.
The mass and volume of helium in the balloon remained constant.
Explain why the pressure exerted by the helium inside the balloon would increase
- particles would have a higher kinetic energy
- increased number of collisions with the walls of the balloon per second
- greater forces exerted in collisions between particles and balloon walls
- greater force exerted on same area
Electricity required practical
- measure the current in component using the ammeter
- measure the potential difference in component in the voltmeter
- vary the resistance of the variable resistor
- record a range of values or current and potential difference which can be done by switching the wires to also get a negative value
- ensure current is low to avoid temperature increase
- switch circuit off between readings
- repeated measurements
Explain how the increased temperature of resistor R would have affected
Student B’s results
current and potential difference would not be directly proportional
because resistance of R would increase
What is meant by the ‘random nature of radioactive decay’?
can’t predict which nucleus will
decay next
When the volume of gas in the syringe increased, the pressure on the inside walls of the syringe decreased.
Explain why.
- there are less frequent collisions
between the particles and the
walls of the syringe - (causing) a lower (average)
force on the walls of the syringe - (and) pressure is the total force
per unit area
Explain the advantage of transmitting electricity at a very high potential difference
- (very high p.d. means) very low
currents - which means less (thermal)
energy is transferred to
surroundings - which increases the efficiency of
power transmission
