Physics Exam June 2023 Flashcards
Transformer X causes potential difference to_____________
Causes current to ___________
Increase
Decrease
Which equation links I, P and R
P = I^2 R
1.60 x 10^9
2000A
Calculate resistance
1.60 x 10^9 = 2000^2 x R
R = 1.60 x 10^9 ➗ 2000^2
R = 400
Which equation links efficiency, total energy input and useful energy output
Efficiency = useful ouput energy transfer ➗ total input energy transfer
34.2 Gj
0.992
Calculate Useful energy output
0.992 = useful energy output ➗ 34.2
Useful energy output = 0.992 x 34.2
= 33.9
Why did student leave thermometer in iron block for few minutes before recording the initial temperature
So thermometer temperature was same as temperature of iron block
What effect will adding insulation have on investigation
The calculated specific heat capacity will be more accurate
The iron block will transfer thermal energy to surroundings at a lower rate
Direct potential difference
Polarity of the potential difference doesn’t charge
Which equation linos Q, E and V
E = QV
Explain the changes in the arrangement and movement of the particles as the ice melted and the temperature increased to 5°C
Particles in solid in regular pattern - liquid random
Particles in solid vibrate - liquid move freely
As ice changes to water temp remains constant as ice ice changes to water potential energy increases
As water warms particles move faster
Internal energy is total kinetic and potential energy of particles
Explain why solar power system improves the reliability of the electric supply to the village
Reduces dependance on main grid
Solar Panels provide continuous source
Describe difference between irradiation and contamination
Irradiation is exposure of person to radiation
Contamination is prescence of radioactive material on person
Calculate number of days for nuclear power station to recieve same dose as a pilot flying for 24 hours
24 hours = 0.072
Number of days = 0.072 ➗ 0.00050
144
Power output for lamp is 1.0W
Potential difference is 5.0V
A student predicts that if power output would be 4.0W if potential differencd was doubled
p. d. would need to double
As Resistance of filament lamp increases
Suggest why the baby bouncer should not be used with babies with mass greater than 12kg
Spring may be permanently extended
Describe energy transfers as the baby moves from position A to position B
Baby has gravitational potential energy
As baby moves down is transferred to kinetic energy then elastic potential energy
All energy is elastic potential energy
What year was this discovered
Electron
1897
What year was this discovered
Neutron
1932
What year was this discovered
Nucleus
1911
What year was this discovered
Proton
1920
Why alpha particle A takes path shown figure 8
Both alpha and nucleus have positive charge
So alpha particle and gold nucleus repel each other
Explain why path of alpha particle B is more tightly curved than the path of alpha particle C
Particle B passes closer to he nucleus
So experiences stronger force
What can be deduced about atom from paths taken by alpha particles D, E, F and G
The atom is mostly empty space
How is the bohr model of the atom different from the nucelar model of atom
In bohr model electrons orbit nucleus at specific distances
How an electron can move up and down between energy levels in an atom
Electron absorbs energy from electromagnetic radiation to move to higher level
To move to lower level electron emits energy in form of electromagnetic radiation
Why pressure increases as more air is pumped into the tyre
More particles
Greater number of collisions with tyre per second
Why air pressure in car tyre changes if temperature of air in tyre increases
As temp increase, air particles have greater kinetic energy
More collisions with tyre per second
Greater force in each collision
Greater force per square meter causes greater pressure
