Science
MediumQ. No. how-does-the-sun-s-heat-reach-the-earth
How does the Sun's heat reach the Earth?
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AConduction
BConvection
CRadiation
DAll three methods
Correct Answer: RadiationYour Answer: C
Last Updated:
The Sun is approximately 150 million kilometres (1.5 × 10⁸ km) from Earth, and the space between them is essentially a vacuum. Option A (Conduction) is incorrect — conduction requires direct physical contact or a connected material medium. Since there is vacuum between the Sun and Earth, conduction cannot occur. You cannot conduct heat through empty space. Option B (Convection) is incorrect — convection requires a fluid medium (gas or liquid) through which heated molecules can physically move. Since space between the Sun and Earth is a vacuum (no matter), convection is impossible. Option C (Radiation) is CORRECT — the Sun's heat reaches Earth through radiation. The image explicitly states: पृथ्वी तक सूर्य की ऊष्मा किस विधि द्वारा पहुँचती है — विकिरण विधि द्वारा. Radiation travels as electromagnetic waves (infrared, visible light, ultraviolet) and does not require any material medium. It travels through the vacuum of space at the speed of light (3 × 10⁸ m/s) in straight lines. The Sun's radiation takes approximately 8 minutes 20 seconds to reach Earth. Option D (All three methods) is incorrect — only radiation can travel through the vacuum of space between the Sun and Earth. Conduction and convection are impossible in vacuum.
FAQ
Common questions and clear answers for this topic.
Heat is a form of energy that transfers between objects or systems due to a temperature difference, moving from a hotter body to a cooler one until thermal equilibrium is reached.
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