(a) Never hold the thermometer by the bulb while reading it.
(b) Wash the thermometer with water or antiseptic solution before and after use.
(c) While performing the experiment, don’t touch the bulb of the thermometer with the wall of the beaker.
(d) Read the thermometer keeping the level of mercury along the line of sight.
The length of wire PQ in case of A is equal to the diameter of the semicircle formed by the wire CDE, in case B. One pin is attached to each wire with the help of wax as shown in figure above. Which pin will fall first? Explain.