Question

A prism of refracting angle 4 is made of a material of refractive
made of a material of refractive index 1.65 find
minimum deviation.
1) 1.3
2)2.6
3)3.9
4 1.8​

Answer 1

Answer:

PRISM

Explanation:

★ MINIMUM DEVIATION { Delta § } ★

»GIVEN ;

» A ( Refracting Angle Of Prism ) = 4°

» μ ( Refractive Index ) = 1.65

♥ FOR ANGLES LESS THAN 10° WE USE

♥ FOR ANGLES LESS THAN 10° WE USE FORMULA ; ♣

★ Delta Minimum {§} = [ μ - 1 ] A ★

» WE GET ;

» § = [ 1.65 - 1 ] × 4

» § = 0.65 × 4 = 2.6

ANSWER :- HENCE ; VALUE OF MINIMUM DEVIATION IS 2.6° .

Answer 2

» A prism of refracting angle 4 is made of a material of refractive made of a material of refractive index 1.65.

Here...

• Refractive index (μ) = 1.65

• Angle of prism (A) = 4

_____________ [ GIVEN ]

• We have to find the minimum deviation of the prism $(\delta)$.

_____________________________

We know that ..

» A + $\delta$ = $i_{1}\:+\:i_{2}$

$i_{1}\:=\:i_{2}\:=\:i$

So,

A + $\delta$ = $i\:+\:i$

A + $\delta$ = $2i$

$\delta$ = $2i$ - A

Now; for very small angled prism

→ $\delta$ = (μ - 1)A

Put the known values in have formula

→ $\delta$ = (1.65 - 1)4

→ $\delta$ = (0.65)(4)

→ $\delta$ = 2.6

______________________________

2.6 is the minimum deviation of the prism.

Option (2) 2.6

__________ [ ANSWER ]

_______________________________