Two forces 3 N and 4 N act at right angles. Resultant magnitude is:
A. 12 N
B. 7 N
C. 1 N
D. 5 N
Answer: Option D
Solution (By JKSSB Mock Tests)
For perpendicular forces: R = √(F₁² + F₂²) = √(9 + 16) = √25 = 5 N. Pythagorean theorem applies for vector addition at 90°. Memory aid: '3-4-5 triangle for perpendicular forces'. Basic vector addition problem testing magnitude calculation, common in mechanics sections of competitive exams.
Explanation:
Thermal radiation is the transfer of heat via electromagnetic waves (primarily infrared). Unlike conduction (which requires physical contact) or convection (which requires fluid movement), radiation can travel through a vacuum. This is how the heat from the Sun reaches the Earth through the vacuum of space.
Explanation:
Lens maker's formula: 1/f = (μ_lens/μ_medium - 1)(...). In water, relative refractive index reduces, so power decreases, focal length increases. Glass in water behaves less converging.
No comments yet. Be the first to start the discussion!