Q2
(A) Give scientific reasons of the following (ANY TWO) 4
i. The value of g is zero at the center of the Earth
The outer surface of a beaker containing ice cubes bet wet in a short while.
In the electric equipment producing heat eg. Iron, electric heater, boiler,
toaster, etc., an alloy such as Nichrome is used not pure metal.
Answers
Explanation:
:
: (1) When ice cubes are placed in a beaker, ice starts melting. The heat required for melting is absorbed from the surrounding air and also from the beaker to some extent. Hence, the temperature of the air and beaker falls.
: (1) When ice cubes are placed in a beaker, ice starts melting. The heat required for melting is absorbed from the surrounding air and also from the beaker to some extent. Hence, the temperature of the air and beaker falls.(2) The capacity of air to hold water vapour depends upon the temperature of the air, and this capacity decreases as the temperature decreases. At a certain low temperature, the surrounding air becomes saturated with water vapour present in it. As the temperature falls further, the air is unable to hold all the water vapour. Hence, the extra water vapour starts condensing on the cold outer surface of the beaker in the form of minute drops. The refore, the outer surface of the beaker containing ice cubes becomes wet in a short while.