Matter in Our S...

Identify the incorrect statement about evaporation

(A) It causes cooling
(B) It increase with increase in humidity
(C) It decreases with increase in temperature
(D) It increases with increase in wind speed

Which of the following is correct about latent heat?

(A) It does not increase the temperature.
(B) It does not change the state of the substance.
(C) It increases the kinetic energy of the molecules.
(D) Ice is more effective in cooling than water at same temperature due to latent heat.

Water kept in an earthen pot becomes cool in summer, because:

(A) Molecules of water escape through pores and cause cooling.
(B) Earthen pots are made up of clay.
(C) It decreases the temperature of water.
(D) In summer, the rate of evaporation of water is faster.

The two major gases present in air are

Three pieces of cloth were soaked in water, alcohol and ether separately and kept on a table. What is the decreasing order of drying of the cloths?

Sulphur dioxide is collected in the lab in a gas jar by upward displacement of air. Which of the following statement is correct regarding the density of the gas?

Which of the two statements is true?

Statement A: The temperature of the liquid becomes constant once it starts boiling.
Statement B: Pressure of air at sea level is 70 cm.

Which of the following is needed by surgeons during surgery?

Match the following with the correct response:-

Which of the following is not a chemical change?

(A) Changing of milk into curd
(B) Freezing of water
(C) Burning of paper
(D) Mixing of iron filling & sand