Question

In which of the following setups would the bulb glow?
(Sample paper 2021-2022)​

Answer 1

In the above-given setup, the bulb would glow in the two setups (i) and (iv).Therefore the correct option for the question is:

(B) i and iv

Justification for the answer:

• When acids and bases and dissolved in pure water they conduct electricity.
• This happens because they form ions that conduct electricity by dissolving in water.

Fig. (i):

In this setup, the solution used is dilute HCl solution(hydrochloric acid) which produces H+ ions in water. Therefore it conducts electricity.

Fig. (ii):

In this setup, a sugar solution is used. When sugar molecules dissolve in water, they do not form ions. Therefore it does not conduct electricity.

Fig. (iii):

In this setup, alcohol is used in the solution. Alcohol is neither acid nor base. It does not form ions in water. Therefore, it does not conduct electricity.

Fig. (iv):

In this setup, lime water that is Ca(OH)2 is used in the solution. Ca(OH)2 calcium hydroxide which is a base forms ions when it is dissolved in water. Therefore it conducts electricity.

The setup in Figures (I) and (iv) only conducts electricity. So the bulb will only glow in these two setups and not others.