Page 148 - Physics - XI

5. Note the temperature of water in both the calorimeters initially at an interval of 1 min till the temperature
of water in calorimeter is 40–30°C above the room temperature and thereafter at intervals of 2 min
when the temperature is 20–10°C above the room temperature.

6. Note the temperature T and T in the observation table and plot graphs between T versus time and T B
A
A
B
versus time for both the calorimeters on the same graph paper.
7. Determine the slope of T versus time graph after 5 min interval.
(ii) Eff ect of Nature of Surface of Container on Rate of Cooling of a Liquid
8. Use the two identical small calorimeters one with black (say C) and the other with highly polished
(say D) surfaces.

9. Repeat the steps (2) to (7).
10. Note the observations and plot a graph by taking time along X-axis and temperature T along Y-axis.
(iii) Eff ect of Material of Container on Rate of Cooling of a Liquid

11. Use the metallic tumbler (say A) and the plastic tumbler (say B) instead of calorimeters.
12. Repeat the steps (2) to (7) as in part (i).

13. Note the observations in the observation table.

Observations

Eff ect of Area of Surface on Rate of Cooling
1. Least count of thermometer = _________°C
2. Least count of stopwatch = _________ s
3. Room temperature = _________°C

Table to study the eff ect of area of surface on rate of cooling
Calorimeter A (Big) Calorimeter B (Small)
S. No.
Time (min) Temperature, T (°C) Time (min) Temperature, T (°C)
B
A
1.
2.
3.
4.
5.

Table to study the eff ect of nature of surface of container

Calorimeter black (C) Calorimeter highly polished (D)
S. No.
Time (min) Temperature, T (°C) Time (min) Temperature, T (°C)
C D
1.
2.
3.
4.

5.

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