To read the pH values, first determine the value of each small division. Between 0 and 2, there are 10 small divisions, so each division represents (2-0)/(10) = 0.2 pH units.

1(c)

i)
To read the pH values, first determine the value of each small division. Between 0 and 2, there are 10 small divisions, so each division represents $\frac{2-0}{10} = 0.2$ pH units.
P1: $0 + (2 \times 0.2) = \boxed{\text{0.4}}$
P2: $4 + (3 \times 0.2) = \boxed{\text{4.6}}$
P3: $6 + (4 \times 0.2) = \boxed{\text{6.8}}$
P4: $12 + (2 \times 0.2) = \boxed{\text{12.4}}$

ii)
pH P1 (0.4) and P2 (4.6) indicate acidic liquids.
Example of a liquid with pH P1 (strongly acidic): Hydrochloric acid.
Example of a liquid with pH P2 (weakly acidic): Lemon juice.

iii)
pH P3 (6.8) indicates a nearly neutral or very weakly acidic liquid.
Example of a liquid with pH P3: Milk.
pH P4 (12.4) indicates a basic (alkaline) liquid.
Example of a liquid with pH P4: Bleach.

iv)

• For liquid P1 (pH 0.4, strongly acidic): Red litmus paper stays red, blue litmus paper turns red.
• For liquid P2 (pH 4.6, weakly acidic): Red litmus paper stays red, blue litmus paper turns red.
• For liquid P3 (pH 6.8, nearly neutral): Red litmus paper stays red, blue litmus paper stays blue.
• For liquid P4 (pH 12.4, strongly basic): Red litmus paper turns blue, blue litmus paper stays blue.

1(d)

i)
Device A: Knapsack sprayer (or Backpack sprayer)
Device B: Watering can

ii)
N: Tank (or Container)
P: Hose (or Delivery tube)
Q: Pump lever (or Pumping handle)
R: Nozzle (or Spray nozzle)
S: Lance (or Spray wand)
T: Rose (or Sprinkler head)
U: Spout

iii)
Use of Device A: To spray pesticides, herbicides, or liquid fertilizers on crops.
Use of Device B: To water plants in a garden or nursery.

iv)
The part labelled Q (Pump lever) is used to pressurize the liquid inside the tank, allowing it to be sprayed out through the nozzle.

v)
One similarity between device A and B is that both are used for dispensing liquids (e.g., water, chemicals) for agricultural or gardening purposes.