Join 60,000+ competitive exam aspirants
or with email
Your Cart
Subtotal₹0
Total₹0
Examoogle • User • info@examoogle.com • EE-2024-8821
Chapter 1 of 12 • Page 1 of 248🔒 Protected PDF • Watermarked
Join 60,000+ competitive exam aspirants
If a train travelling at a speed of 90 km/h crosses a pole in 5 sec, then the length of train is:
140 m
152 m
104 m
125 m
125 m
Convert speed from km/h to m/s by multiplying by 185 (90 × 5/18 = 25 m/s), then multiply by time: 25 × 5 = 125 m.
Train speed = 90 km/h, Time taken to cross a pole = 5 sec
L=v×t
Convert speed from km/h to m/s by multiplying by 185 (90 × 5/18 = 25 m/s), then multiply by time: 25 × 5 = 125 m.
Forgetting to convert km/h to m/s, which would lead to 90 × 5 = 450, an incorrect value not in the options.
Convert speed to m/s
To keep units consistent, convert km/h to m/s by multiplying with 185.
90×185=5×5=25 m/s
Apply distance formula
When a train crosses a pole, the distance covered is equal to the length of the train (L). Using L=v×t:
L=25×5
Calculate final length
Multiplying the values gives the total length of the train.
L=125 m
D is correct because the calculated length of the train is 125 m.
Always ensure units match (km/h vs m/s) in railway problems, as exams frequently use these for simple unit conversion traps.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download • 100K+ Aspirants