[amp_mcq option1=”both arms are horizontal” option2=”semaphore arm lowered but warner arm horizontal” option3=”both semaphore and warner arms lowered” option4=”none of the above” correct=”option3″]<\/p>\n
The correct answer is C. both semaphore and warner arms lowered<\/strong>.<\/p>\n A semaphore is a railway signal consisting of a movable arm or arms that indicates the state of the line ahead. A warner is a railway signal that is used to warn drivers of a potential hazard ahead. When semaphore and warner are installed on the same post, the stop indication is given when both arms are lowered. This is because the lowered arms indicate that the line ahead is blocked and that trains should not proceed.<\/p>\n Option A is incorrect because both arms being horizontal indicates that the line ahead is clear and that trains can proceed. Option B is incorrect because the lowered semaphore arm indicates that the line ahead is blocked, but the horizontal warner arm indicates that the line is clear. Option D is incorrect because both semaphore and warner arms must be lowered in order to indicate a stop.<\/p>\n","protected":false},"excerpt":{"rendered":" [amp_mcq option1=”both arms are horizontal” option2=”semaphore arm lowered but warner arm horizontal” option3=”both semaphore and warner arms lowered” option4=”none of the above” correct=”option3″]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[653],"tags":[],"class_list":["post-8077","post","type-post","status-publish","format-standard","hentry","category-railway-engineering","no-featured-image-padding"],"yoast_head":"\n