Advertisements
Advertisements
Question
Why is the freezing chest in a refrigerator fitted near its top?
Advertisements
Solution
Freezing chest in a refrigerator is fitted near the top, because it cools the remaining space of the refrigerator by convection current. Air near the top comes in contact with the freezing chest gets cooled, becomes denser and therefore descends while the hot air from the lower part rises and hence convection currents produced cool the whole space inside.
APPEARS IN
RELATED QUESTIONS
Write true or false for a given statement.
On touching a lump of ice, we feel cold because some heat passes from our body to the ice.
Write true or false for a given statement.
Medium is necessary for the transfer of heat by radiation.
Select the correct alternative
If we add a lump of ice to a tumbler containing water,
Select the correct alternative
The vacuum kept in between the walls of a thermos flask reduces the heat transfer by
State the direction of heat transfer by way of convection.
Why are the houses in Rajasthan painted white?
What are the modes of heat transfer?
Why are heaters fitted near the floor and air conditioners near the ceiling of a room?
Take a sheet of paper. Draw a spiral on it as shown in Figure. Cut out the paper along the line. Suspend the paper as shown in Figure above a lighted candle. Observe what happens. Think of an explanation.
Take two similar transparent glass bottles having wide mouths. Put a few crystals of potassium permanganate or pour a few drops of ink in one bottle. Fill this bottle with hot water. Fill the other bottle with cold water. Cover the cold water bottle with a thick piece of paper such as a postcard. Press the postcard firmly with one hand and hold the bottle with the other hand. Invert the bottle and place it on top of the hot water bottle. Hold both the bottles firmly. Ask some other person to pull the postcard. Observe what happens. Explain.
