# 9 - Refraction Questions Answers

the quantity that doesnot change when a spherical mirror breaks

**Asked By: KAVERITHOUTAM**4 year ago

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the quantity that doesnot change when a spherical mirror breaks

**Asked By: KAVERITHOUTAM**4 year ago

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if fv and fr are d focal lenth of concave lens than which one vyl be gr8ter

ans given is fv> fr why, as wavelength is directly proptional to f isn't it shld be fr>fv

**Asked By: SARIKA SHARMA**6 year ago

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the diameter of aperture of planoconvex lens is 6 cm & its maxm thickness is 3mm . If the velocity of light in the material of lens is 2X 10^{8}m/s , then what will be its focal length?/

ans 30cm

**Asked By: SARIKA**6 year ago

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2 thin similar convex glass pieces are joined together front to front with its rear portn silvered such that a sharp image is formed 20cm from the mirror . When the air b/w glass pieces is replaced by H2O (u=4/3) then image formed from the mirror is at a distance ______________??

ans 12cm

**Asked By: SARIKA**6 year ago

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if ω_{1 &}ω_{2} are dispersive powers of lenses of focal length f1 & f2 respectively . then the condition of chromatic aberration for two lenses in contact is

1) ω1/ω2 = f2/f1

2) ω1/ω2 = f1/f2

3) ω1/ω2= - f1/f2

4) ω2/ω1= f1/f2

**Asked By: HIMANSHU**6 year ago

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**Answer Strategies and trick by Manish sir**(it will help you to solve it by yourself)

3 is the true condition and can be proved

what is meant by rate of change of transverse magnification

**Asked By: NIKHIL VARSHNEY**7 year ago

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**Answer Strategies and trick by Manish sir**(it will help you to solve it by yourself)

transverse magnification m = v/u so rate of change of trasverse magnification is dm/dt. calculate by differentiation