Past paper improvements paper 1 Flashcards
(11 cards)
What is meant by a zero error
Zero error is a systematic error that occurs when a measuring instrument does not read zero when it should.
E.G) ammeter displays a reading when not connected to the circut
When replaced, the cells were put into the torch the wrong way around. Explain why the tourch did not work
Charge will not flow through a diode in the opposite dirrection
Because a diode has a very high resistance in the reverse dirrection
Percentage increase equation
(New value - original value / original value) x 100
Give as many reasons as possible why the enviromental advantages of using gas-fired power stations to generate electricity is better then using coal-fired power stations
- No sulfur dioxide realsed
- Does not cause acid rain
- No particulates realsed
- Doesnt cause global dimming
- Less carbon di-oxide relesed (Per KG of fuel)
- Less global warming
- No solid waste
- Gas mining is less enviromentaly destructive than coal mining
Why is it good that half lives of a material are shorter for radio-active waste
Activity decreases quickly
The risk of harm decreases quicker
At the bottom of the slide all riders have approximately the same spped explain why
- Decrease in Gravitational energy is a decrease in Kentic energy
- Mass cancels out on both sides of the equation
- The final speed only depends on verticle height
- Variations will occur do the intial speed or other factors like air resistance
When the kettle was switched on the temperature of the water did not immediately start to increase suggest one reason why
The heating elements of the kettle takes time to heat up
The student thought that taking a fourth reading would improve the precision of the results
The fourth reading was 16.2
explain why the student is wrong
Precise results show little variation
The 4th result was further away from the mean then compared to the other resuts
Explain why adding resistors in parrel decreases the total resistance
Multiple paths for electrons to flow
Total current is greater for same voltage
Why would have a electrican touching a when replacing switch when wire touching object
One wire in the switch is live, the electrican is earthed.
So there will be a large P.D between switch and man causing a eletic shock
The Uk mains frequency is 50 Hz
Explain why it would be safer if the UK mains frequency was not 50 Hz
50Hz is the lowest (maxinum) let go current
A different frequency would allow people to let go at a higher current
