A ray of light is incident at an angle α on the boundary separating two transparent media. It is transmitted. If the angle of incidence is increased very slightly, the ray gets reflected in the same medium. The difference between angles of deviation in the two cases will be close to

Question

A ray of light is incident at an angle α on the boundary separating two transparent media. It is transmitted. If the angle of incidence is increased very slightly, the ray gets reflected in the same medium. The difference between angles of deviation in the two cases will be close to (A) α (B) 90°-α (C) 180°-α (D) 180°-2 α

Tardigrade Admin · Accepted Answer

When the ray is incident at the critical angle α, the angle of deviation is (90°-α) whereas just after this (that is at an angle slightly greater than the critical angle) the angle of deviation is (180°-2 α).

Q. A ray of light is incident at an angle $α$ on the boundary separating two transparent media. It is transmitted. If the angle of incidence is increased very slightly, the ray gets reflected in the same medium. The difference between angles of deviation in the two cases will be close to

$α$

$9 0^{\circ} - α$

$18 0^{\circ} - α$

$18 0^{\circ} - 2 α$

When the ray is incident at the critical angle $α$ , the angle of deviation is $(9 0^{\circ} - α)$ whereas just after this (that is at an angle slightly greater than the critical angle) the angle of deviation is $(18 0^{\circ} - 2 α)$ .

Q. A ray of light is incident at an angle α on the boundary separating two transparent media. It is transmitted. If the angle of incidence is increased very slightly, the ray gets reflected in the same medium. The difference between angles of deviation in the two cases will be close to

α

90∘−α

180∘−α

180∘−2α

When the ray is incident at the critical angle α, the angle of deviation is (90∘−α) whereas just after this (that is at an angle slightly greater than the critical angle) the angle of deviation is (180∘−2α).

Q. A ray of light is incident at an angle $α$ on the boundary separating two transparent media. It is transmitted. If the angle of incidence is increased very slightly, the ray gets reflected in the same medium. The difference between angles of deviation in the two cases will be close to

$α$

$9 0^{\circ} - α$

$18 0^{\circ} - α$

$18 0^{\circ} - 2 α$

When the ray is incident at the critical angle $α$ , the angle of deviation is $(9 0^{\circ} - α)$ whereas just after this (that is at an angle slightly greater than the critical angle) the angle of deviation is $(18 0^{\circ} - 2 α)$ .