When a body is taken to a height equal to radius of Earth from surface, its weight becomes MCQ with Answer and Explanation

When a body is taken to a height equal to radius of Earth from surface, its weight becomes
A. Half
B. Same
C. Double
D. One-fourth
Answer: Option D
Solution (By JKExamLibrary)
g' = g (R/(R+h))². If h=R, g' = g (R/2R)² = g/4. Weight = mg' = mg/4, one-fourth. Above surface, g decreases with square of distance from centre.

This question belongs to: Science Physics

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The phenomenon of beats in sound waves is due to:
A. Reflection
B. Diffraction
C. Refraction
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Correct Answer: Option D


Explanation:
Beats occur when two sound waves of slightly different frequencies interfere, causing periodic variation in amplitude (loudness). Beat frequency = |f₁ - f₂|. This is a superposition/interference phenomenon. Reflection, refraction, diffraction don't produce beats. Memory tip: 'Beats = interference of close frequencies; used in tuning instruments'. This conceptual question tests wave superposition understanding, frequently examined in competitive exams. Always distinguish beats (amplitude modulation) from resonance (amplitude increase at natural frequency).

This question belongs to: Science Physics
Question #2 Report Error
The radius of curvature of a convex mirror of focal length 20 cm is
A. 30 cm
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Correct Answer: Option D


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This question belongs to: Science Physics
Question #3 Report Error
The work done in moving a charge of 2 C between two points with potential difference of 12 V is:
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Correct Answer: Option C


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This question belongs to: Science Physics