When you have fever, keeping a piece of linen cloth dipped in water on your forehead helps reduce temperature.

The swelling of a piece of wood occurs when placed in water. Would you describe this as growth? Explain it.

Light of a single colour is passed through a liquid having a piece of glass suspended in it. On changing the temperature of liquid, at a particular temperature the glass piece is not seen. (i) When is the glass piece not seen ? (ii) why is the light of a single colour used ?

A tuning fork vibrating with a frequency of 512 Hz is kept close to the open end of a tube filled with water , figure. The water level in the tube is gradually lowerd. When the water level is 17cm below the open end, maximum intensity of sound in heard. If the room temperature is 20^(@)C , calculate (a) speed of sound in air at room temperature. (b) speed of sound in air at 0^(@)C (c) if the water in the tube is replaced with mercury, will there be any difference in your observations?

How is the gravitational force between two point masses affected when they are dipped in water keeping the separation between them the same ?

A capillary glass tube records a rise of 20cm when dipped in water. When the area of cross-section of the tube is reduced to half of the former value, water will rise to a height of

Is the thermometer reading of the temperature of air (in shade) the same as the temperature of sand or water? What do you think is the reason for this? And why does the temperature have to be measured in the shade?

A capillary glass tube records a rise of 20cm when dipped in water. When the area of cross-section of the tube is reduced to half of the former value, water will rise to a height of (A) 10sqrt(2)cm (B) 10cm (C) 20cm (D) 20sqrt(2)cm

Write your observation and conclusion for the following: (a) When few marbles are put in a glass half filled with water. (b) Ice is kept at room temperature.

If a 5 cm long capillary tube with 0.1 mm internal diameter, open at both ends, is slightly dipped in water having surface tension 75 dyn//cm , state whether: (i) water will rise halfway in the capillary, (ii) water will rise up to the upper end of capillary, (iii) water will overflow out of the upper end of capillary. Explain your answer.

The following graph show the temprature of a patient in a hospital, recorded every hour, (a) What was the patient's temperature at 1 p.m.? *b) When was the patient's temperature 38.5^@ C ? (c) The patient’s temperature was the same two times during the period given. What were these two times? (d) What was the temperature at 1.30 p.m.? How did you arrive at your answer? (e) During which periods did the patients’ temperature showed an upward trend?