Worksheets8k Final revision
Total questions: 54
Worksheet time: 38mins
If you check your measuring equipment and calibrate it to make sure it's properly zeroed, your results will be more...
Accurate
Reliable
Precise
Fair
If you measure to finer intervals eg: mm instead of cm then the results will be more...
Accurate
Reliable
Precise
Fair
If you control variables so that only the independent variable affects the dependent variable, then the experiment will be...
Accurate
Reliable
Precise
Fair
Precision -
How close measurements are to one another
How close measurements are to the true or accepted value
How close marked units are on a ruler
How close measurements are repeated
Given a true value of 7.15 cm the following measurements would be considered
7.00 cm
7.12 cm
7.07 cm
7.15 cm
Accurate
Precise
Accurate and precise
Which ruler is more accurate and precise?
(Ruler 1 is on top)
Ruler 1
Ruler 2
Ruler 3
True or False: The independent variable causes something to change.
True
False
Which electric meter has a reading of 1365 kilowatt-hour?
The electric meter reading last month was 3267 kwh. This month the reading is 3897 kwh. How much electricity was consumed for the whole month?
635 kwh
675 kwh
630 kwh
670 kwh
At home, a laptop uses 50-watts per hour when its being used.
How many kWh does it consume if it is used for one day?
0.4 kwh
1.2 kwh
0.05 kwh
600 kwh
The unit for Electrical Energy when paying our bill is
Joules
kWh
Watts
kJ
This is Lavinder's TV. What is the power rating of this TV?
Toshiba
1000 W
SMART TV 40
RM 899.
A toaster, rated 1500 W 240 V, is switched on for 15 minutes. Calculate the energy used.
(a)
An air-con, rated 1.8 kW 240 V, is switched on for 10 minutes. Calculate the energy used.
1 080 000 J
144 000 J
2400 J
18 J
The electrical energy used by a fan for 4 minutes is 170 kJ. Calculate the power of this fan in W. ( NO decimal)
(a)
An oven rated 750 W, 220 V is switched on for 45 minutes. Calculate the cost of energy that is used by the oven if the cost per 1 unit is 30 sen? ( 1 Unit = 1 kWh)
3 sen
17 sen
16875 sen
4 sen
if you use your laptop 5 hours a day for 1 year - how much will you have to pay if the cost of 1 kiloWatt hour is 20 cents
Give your answer to the nearest $
(a)
Calculate the useful energy output for a device when its total energy input is 60 kJ and it has an efficiency of 23%.
answer in joules but do not type the units
(a)
Calculate the useful energy output for a light bulb when total energy input is 3000 J and it has an efficiency of 32%.
answer in joules but do not type the units
(a)
Efficiency is calculated by useful energy output divided by total energy input, expressed as a percentage
False
True
A kettle uses 100J of electrical energy to produce 7J of sound energy and 93J of thermal energy. How efficient is the kettle?
100%
7%
93%
95%
Total energy = 200J
Useful energy = 20J
Workout the efficiency of this lightbulb.
efficiency = total energy inuseful enegy ×100
100%
80%
40%
10%
t = 25 seconds
P = ???
Which of these objects has the coldest TEMPERATURE?
Orange
Ice cube
Sun
Monkey
Kinetic energy is...
energy carried in ultraviolet waves
energy stored in food
energy in motion
energy from splitting an atom
At higher temperatures
particles in an object have less kinetic energy
particles in an object move faster
a gas contracts
What is boiling in celsius
212°
32°
100°
1,000,000°
when it is hot the atoms move...
slow
fast
still
there are no atoms
what is the scale mainly used by scientists
fahrenhiet
celcius
kelvin
SOS
What is the Law of Conservation of Energy?
Energy cannot be created, but can be destroyed as it transforms.
Energy can be created and destroyed as it converts to other forms.
Energy can be created and lost as heat as it converts to other forms.
Energy cannot be created nor destroyed only transformed to other forms.
1 kg of ice has more internal energy than 1kg of steam
No TRUE
TRUE
The direction of heat flow
cold to hot
hot to cold
up
out
When a liquid changes into a gas,
Potential energy is increasing.
Kinetic energy is decreasing.
Temperature is decreasing.
Kinetic energy is increasing.
What is thermal energy that is transferred through empty space?
(a)
What is thermal energy that is transferred when two objects of different temperatures touch?
(a)
Thermal energy always moves from object with ...
no heat to objects with heat
more kinetic energy to objects with less kinetic energy
direct contact between them
higher temperatures to objects with lower temperatures
Boiling Water
Conduction
Convection
Radiation
Which one is a benefit of heat transfer by convection?
It gives energy for plants to grow
It causes smoke to rise
It makes frying of food possible
Which of the following heat transfer is characterized by the movement of liquids or gases?
Conduction
Convection
Radiation
Sana all
Which of the following would reduce the dissipation of energy from a house to the surroundings?
insulation
large walls
thin walls
metal walls
People sometimes put foil behind radiators...
...to reflect the infrared radiation back into the room
...because who wouldn't want a bit of bling behind their radiator?
..to absorb the dissipated heat
...to stop the walls getting damaged by the heat
Convection Current
Conduction
Radiation
Night
What is an insulator?
A material that allows heat to pass through
A material that does not allow heat to pass through
As an electric drone accelerates upwards its __________________________ energy increases and its __________________________ energy increases.The __________________________ energy store of the battery decreases.
kinetic ; gravitational potential ; chemical
chemical ; gravitational potential ; kinetic
kinetic ; gravitational potential ; nuclear
kinetic ; elastic potential ; chemical
Which type of surface is the best absorber of infra-red rays?
black and rough
black and smooth
white and rough
white and smooth
The diagram shows a refrigerator. The cooling unit is placed at the top. The cooling unit cools the air near it. What happens to the density of the air as it cools, and how does it move?
The density of air increases. It moves down.
The density of air increases. It moves up.
The density of air decreases. It moves down.
The density of air increases. It moves up.
The radiators on motor cars are painted black because ________.
black surface is more beautiful
a black surface can conduct heat better
a black surface is a good radiator of infra-red rays
it will not get dirtt easily
A teapot is needed to keep tea hot for a long period of time. Which of the following best explains why teapots are usually made of a shiny metal?
Shiny surfaces are good absorbers of infra-red radiation.
Shiny surfaces are good emitters of infra-red radiation.
Shiny surfaces are poor absorbers of infra-red radiation.
Shiny surfaces are poor emitters of infra-red radiation.
