Railway RRB NTPC: 50 High-Yield General Science Concepts

The Railway Recruitment Board (RRB) dedicates substantial weightage to Class 9 and 10 NCERT science. Here is a concentrated overview of the most repeated questions:

Key Physics Principles - **Work, Power & Energy**: 1 Horsepower = 746 Watts. Work done when displacement is perpendicular to force (like carrying a load horizontally) is ZERO. - **Optics**: A concave mirror is used by dentists and for car headlights to produce parallel beams. Convex mirrors are used as vehicle rear-view mirrors due to wider field of view. - **Acoustics**: Velocity of sound is maximum in solids (Steel ~5960 m/s) and zero in vacuum.

Vital Biological Systems - Normal human blood pH is slightly alkaline: 7.35 to 7.45. - The Master Gland of the endocrine system is the Pituitary Gland, controlled by the Hypothalamus.