EduNinjaA copper cooking pan contains water. Fig. 2.1 shows the pan on a hotplate of a cooker.
Fig. 2.1
Copper is a metal.
The outside surface of the cooking pan is kept clean by regular polishing.
Explain one other advantage of keeping the surface of the pan shiny.
Solar heating panels consist of pipes carrying water that absorb radiation from the Sun.
Which texture and colour is the surface of the pipes so that the temperature of the water rises at the quickest rate?
dull black
dull white
shiny black
shiny white
Fig. 4.1 shows part of a container used to store a mixture of liquid and gaseous oxygen.
Fig. 4.1
The temperature of the liquid oxygen is .
The container is made of steel and there is a vacuum between the inner and outer walls. The outer wall of the container is at room temperature.
State two methods of thermal energy transfer that a vacuum prevents.
1
2
A solar water heater is designed to absorb energy from sunlight.
Which surface texture and colour would be best for the solar water heater?
dull black
shiny black
dull white
shiny white
In countries where it is usually hot, houses are often painted white.
What is the reason for this?
White surfaces are good reflectors of infrared radiation.
White surfaces are good conductors of infrared radiation.
White surfaces are good absorbers of infrared radiation.
White surfaces are good emitters of infrared radiation.
1. Two metal spheres of different diameters are heated to in a hot oven. The two spheres are removed from the oven.
State and explain any difference in the initial rates of emission of radiation of thermal energy between the two spheres.
2. One hot sphere is now heated in a hotter oven.
State and explain any effect on the rate of emission of radiation of thermal energy from that sphere when it is removed from the hotter oven.
Four thermometers, with their bulbs painted different colours, are placed at equal distances from a radiant heater.
Which thermometer shows the slowest temperature rise when the heater is first switched on?
dull black
dull white
shiny black
shiny white
Some hot water is sealed inside a metal can. The can is in a vacuum in outer space. The hot water slowly cools down.
How does the thermal energy escape into space?
by conduction then convection
by conduction then radiation
by evaporation then convection
by evaporation then radiation
Two samples of the same material have the same mass but different surface areas.
Each sample is heated to the same temperature and then left to cool to room temperature.
Each sample is allowed to cool to the same final temperature.
Which row correctly compares the decrease in internal energy and the initial rate of cooling for each sample?
decrease in internal energy
initial rate of cooling
X loses more internal energy than Y
X cools down faster than Y
Y loses more internal energy than X
Y cools down faster than X
X and Y lose the same quantity of energy
X cools down faster than Y
X and Y lose the same quantity of energy
Y cools down faster than X
Which piece of equipment is designed to produce a type of electromagnetic wave?
electric fire
electric generator
electric motor
electromagnet