A ray of light travelling in the direction (1/2)( hati+√3 hatj) is incident on a plane mirror. After reflection, it travels along the direction (1/2)( hati-√3 j). The angle of incidence is

Question

A ray of light travelling in the direction (1/2)( hati+√3 hatj) is incident on a plane mirror. After reflection, it travels along the direction (1/2)( hati-√3 j). The angle of incidence is (A) 30° (B) 45° (C) 60° (D) 75°

Tardigrade Admin · Accepted Answer

Angle between given rays is 120°, so angle of incidence is 30° <img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/23453ce0b724b1b167d5e706b82a3fd9-.png" />

Q. A ray of light travelling in the direction $\frac{1}{2} (\hat{i} + 3 \hat{j})$ is incident on a plane mirror. After reflection, it travels along the direction $\frac{1}{2} (\hat{i} - 3 j)$ . The angle of incidence is

$3 0^{\circ}$

$4 5^{\circ}$

$6 0^{\circ}$

$7 5^{\circ}$

Angle between given rays is $12 0^{\circ}$ , so angle of incidence is $3 0^{\circ}$

Q. A ray of light travelling in the direction 21​(i^+3​j^​) is incident on a plane mirror. After reflection, it travels along the direction 21​(i^−3​j). The angle of incidence is

30∘

45∘

60∘

75∘