7.8
5.8
6.8
4.8
Answer is Right!
Answer is Wrong!
The correct answer is A. 7.8 kg/cm2.
The brake pipe pressure (BP pressure) is the pressure of the air in the brake pipe. It is used to control the brakes on a train. The BP pressure must be at least 7.8 kg/cm2 at the starting station of a 40 BCN air braked train. This is to ensure that the brakes are working properly and that the train can stop safely.
Option B is incorrect because the BP pressure must be at least 7.8 kg/cm2, not 5.8 kg/cm2.
Option C is incorrect because the BP pressure must be at least 7.8 kg/cm2, not 6.8 kg/cm2.
Option D is incorrect because the BP pressure must be at least 7.8 kg/cm2, not 4.8 kg/cm2.