$CATEGORY: Science - Khan Academy/10.Light-Reflection and Refraction/10.Light-Reflection and Refraction--Refraction Of Light

//Multiple Choice

{
~ 1/v + 1/u \= 1/f
= 1/v - 1/u \= 1/f
~ v / u \= h_i / h_o
~ None of the Above
}

In the lens formula, v stands for 
{
~ Object distance
~ Focal length
= Image distance
~ None of the Above
}

The lens formula applies to 
{
~ Convex lenses only
~ Concave lenses only
= Both convex and concave lenses
~ None of the Above
}

If an object is placed at the focus of a convex lens, the image formed is 
{
= At infinity
~ At the focal point
~ Between the lens and focus
~ None of the Above
}

The nature of the image formed by a concave lens is 
{
~ Real and inverted
~ Real and erect
= Virtual and erect
~ None of the Above
}

//True or False

The lens formula is applicable only for convex lenses. {F}

A concave lens always forms a virtual image. {T}

For a convex lens, if the object is at the focus, the image is formed at infinity. {T}

The lens formula is 1/v + 1/u \= 1/f {F}

The image formed by a convex lens can be both real and virtual. {T}



//Match the following

Match the following items from Column A with their correct corresponding options from Column B\:
{
=Convex lens, object beyond 2F -> Image between F and 2F, real, inverted
=Concave lens, object anywhere -> Virtual, smaller image
=Convex lens, object at F -> Image at focus, real, inverted
=Convex lens, object between F and 2F -> Real, magnified image
=Concave lens, object at infinity -> Virtual, erect image
}


//******** END **********