$CATEGORY: Science - Khan Academy/11.Human Eye and Colourful World/11.Human Eye and Colourful World--Atmospheric Refraction

//Multiple Choice

What is the primary reason for advanced sunrise and delayed sunset? {
    ~Earth's rotation
    =Atmospheric refraction
    ~Earth's revolution
    ~None of the above
}

Due to atmospheric refraction, the Sun is visible\: {
    ~Only when it is above the horizon
    =Before it actually rises and after it sets
    ~For the same duration regardless of refraction
    ~None of the above
}

How much earlier does the Sun appear to rise due to atmospheric refraction? {
    =2 minutes
    ~4 minutes
    ~5 minutes
    ~None of the above
}

What phenomenon makes the Sun appear slightly above the horizon after it has set? {
    ~Diffraction
    ~Dispersion
    =Refraction
    ~None of the above
}

The Sun is visible for a few minutes after it has actually set due to\: {
    ~The curvature of Earth
    ~Reflection of light from the Moon
    =Bending of light rays in Earth's atmosphere
    ~None of the above
}

//True or False

The advanced sunrise and delayed sunset are caused by the scattering of sunlight in the atmosphere. {F}

The Sun appears to rise about 2 minutes earlier than its actual rise time due to atmospheric refraction. {T}

Atmospheric refraction causes the Sun to appear smaller during sunrise and sunset. {F}

Due to atmospheric refraction, we see the Sun for a few minutes even after it has set. {T}

The effect of advanced sunrise and delayed sunset happens because Earth's rotation speeds up at the horizon. {F}

//Fill in the blanks



//Numericals



//Match the following

Match the following items from Column A with their correct corresponding options from Column B\:
{
=Advanced sunrise -> Sun appears earlier than actual rise
=Delayed sunset -> Sun appears above horizon after actual set
=Atmospheric refraction -> Bending of light in Earth's atmosphere
=Time difference due to refraction -> 2 Minutes
=Apparent position of the Sun -> Slightly above actual position
}


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