Question

Four students (A), (B), (C) and (D) independently observed the evaporation of water under different conditions, and recorded the temperature of water at regular intervals as shown below.
Student
Placing of experimental set up in/under
Temperature recording for 15 minutes
(A)
sun
increased gradually
(B)
open air
decreased gradually
(C)
a fan
initially increased, then became constant
(D)
a corner of the room
initially increased, then gradually decreased
The correct recording of observations is that of the student:
(1) (A)
(2) (B)
(3) (C)
(4) (D)

Answer 1

Explanation:

The correct recording of observations is that of the student:

(1) (A)

(2) (B)

(3) (C)✔️✔️

(4) (D)

Answer 2

The correct recording of observations is that of the student (2) (B).

The table given in the question is attached below.

When the jar of heated water is placed in open air. The temperature of the water gradually decreases. This is because the evaporation takes place in the water.

Due to evaporation, the heat energy is taken with the gas evaporated from the water.

Rest of the observations are wrong because:

• In observation (A) the temperature of the water is maintained does not increase when in kept in the sun.
• In observation (B) the temperature decreases rapidly with evaporation.
• In observation (D) the position of the jar in the room does not affect the temperature of the water.