Question

Consider the statements given below and choose the correct option :
Statement 1 : Angle of deviation produced by a prism depends on the angle of the prism.
Statement 2 : Dispersion takes place in a prism because the refractive index of the refracting medium is different for different wavelengths.

• A. Statements 1 & 2 both are correct.
• B. Statement 1 is correct, but Statement 2 is incorrect.
• C. Statements 1 & 2 both are incorrect.
• D. Statement 1 is incorrect, but Statement 2 is correct.

Hint:

Violet light has the shortest wavelength, highest refractive index, and undergoes the maximum deviation.
Red light has the longest wavelength, lowest refractive index, and undergoes the minimum deviation.

Answer 1

The Correct Option is A

Step 1: Test statement 1 using the prism formula.
The deviation produced by a prism is \[ \delta = i + e - A \] where \(A\) is the prism's own angle. Because \(A\) sits directly inside this formula, changing the prism's angle changes \(\delta\), so statement 1 holds true.
Step 2: Test statement 2 using how refractive index behaves with colour.
Glass does not bend every colour of light by the same amount, violet light experiences a slightly higher refractive index than red light does. This wavelength dependence of \(\mu\) is exactly why passing white light through a prism spreads it into a rainbow, so statement 2 also holds true.
Step 3: Combine the results.
Since checking each statement against its underlying formula shows both are physically accurate descriptions of prism behaviour, neither can be dismissed.
\[ \boxed{\text{Both statements 1 and 2 are correct}} \]