1. Choose the correct option. i) When seen from below, the blades of
a ceiling fan are seen to be revolving
anticlockwise and their speed is
decreasing. Select correct statement
about the directions of its angular
velocity and angular acceleration.
(A) Angular velocity upwards, angular
acceleration downwards.
(B) Angular velocity downwards,
angular acceleration upwards.
(C) Both, angular velocity and angular
acceleration, upwards.
(D) Both, angular velocity and
angular acceleration, downwards.

angular velocity upwards

angular accelaration downwards!!

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.

which three statements are true about all alloys?