Radiation

Q. On what factor(s) the heat absorbed by a body by radiation depend(s) on:​

1. Distance from the source
2. Orientation
3. Colour
4. All of these

Q.

At what speed do heat radiations travel?

Q.

What is blackbody radiation?

Q.

On what factors does the heat emitted by a hot body depend?

Q.

All objects radiate heat but the amount of heat radiated from an object depends on its___________.

Q.

Fill in the blanks.

The amount of heat radiated by a black surface depends on its _______________.

Q. Explain briefly the process of heat transfer by radiation.

Q.

Who discovered blackbody radiation?

Q. For the effective radiation of heat by an electric room heater, which of the following can be done to the reflector panel?

1. Polish it
2. Paint it red
3. Paint it green
4. Paint it black

Q.

State whether the given statement is true or false.

Heat from the sun reaches us by the process of convection.

1. True
2. False

Q. Which type of clothes are preferred during the month of December in our country?

1. Dark coloured clothes
2. Light coloured clothes
3. Cotton clothes
4. Rain coats

Q. Why is it advisable to wear light coloured clothes during summer?

1. They are cheaper.
2. They absorb less heat.
3. They absorb more heat.
4. They are more beautiful to the eyes.

Q.

What are the factors on which the heat emitted by a hot body depends?

Q. Is it possible for an object in a vacuum to have 0 heat if the object doesnt experience any radiation?

Q. A solid sphere and a hollow sphere of the same material and of equal radii are heated to the same temperature.

(a) Both will emit equal amount of radiation per unit time in the biginning
(b) Both will absorb equal amount of radiation from the surrounding in the biginning.
(c) The initial rate of cooling (dT/dt) will be the same for the two spheres
(d) The twp spheres will have equal temperature at any instant

Q. describe the rubbed ford experiment expain effect of intensity of radiation 2 effect of frequency