The number of significant figures in 3.00 × 10⁸ is
A. 1
B. 2
C. 8
D. 3
Answer: Option D
Solution (By JKSSB Mock Tests)
Scientific notation: 3.00 has three significant figures (3,0,0). Exponent part not counted. It's a clear way to show precision. 3×10⁸ has 1, 3.0×10⁸ has 2.
Explanation:
Using the second equation of motion for free fall: h = ut + ½gt². Since it is dropped, initial velocity (u) = 0. Time (t) = 4s, g = 10 m/s². The height h = 0 + ½(10)(4)² = 5 × 16 = 80 meters.
Explanation:
Apparent frequency change depends on relative velocity between source and observer with respect to medium. Both motions contribute: f' = f(v±v_o)/(v∓v_s). Memory tip: 'Approaching ⇒ higher pitch; receding ⇒ lower pitch'. Conceptual question testing Doppler effect fundamentals, frequently examined in competitive exams.
No comments yet. Be the first to start the discussion!