A hydraulic press has a ram of 15 cm diameter and plunger of 1.5 cm. It is required to lift a weight of 1 tonne. The force required on plunger is equal tc__________________?

A. Potassium permanganate
B. Sulphuric acid and napthamine
C. Phenol-di -sulphuric acid potassium hydroxide
D. None of these

A. 1.5
B. 2.0
C. 3.0
D. 4.0

A. The particular manhole and one manhole on upstream and one manhole on downstream should remain open for 30 minutes
B. Proper tests for the presence of poisonous gases must be carried out
C. The men entering the manhole should be advised to smoke in the sewer
D. Warning signals should be erected