[amp_mcq option1=”Fisrt Stop signal” option2=”Stop signal” option3=”Last Stop signal” option4=”None of these” correct=”option2″]
The correct answer is: B. Stop signal
A stop signal is a railway signal that indicates to a train that it must come to a complete stop before proceeding. It is usually a red light, but may also be a semaphore arm or a flashing light.
A block section is a section of track that is protected by a stop signal. This means that no train is allowed to enter a block section until the stop signal has been cleared. This helps to prevent collisions between trains.
The first stop signal is the first signal that a train encounters when entering a block section. The last stop signal is the last signal that a train encounters when leaving a block section.
Option A is incorrect because the first stop signal is not the only signal that can protect a block section. Option C is incorrect because the last stop signal is not the only signal that can protect a block section. Option D is incorrect because there is always at least one stop signal in a block section.