The diagram shows a ray PQR travelling through a glass slab. Which option in the table gives the correct name for all three rays?
| P | Q | R | |
| A | Incident ray | Emergent ray | Refracted ray |
| B | Incident ray | Refracted ray | Emergent ray |
| C | Emergent ray | Incident ray | Refracted ray |
| D | Emergent ray | Refracted ray | Incident ray |
The correct answer is B
The bumpers and door handles of motor cars, taps etc. are coated with silvery layer of chromium because
(i) It does not easily get corroded.
(ii) It forms a hard layer which does not easily get scratched.
(iii) It tarnishes quickly.
(iv) It is cheap.
Which of the following options is correctly identifies true (T) or false (F)?
| (i) | (ii) | (iii) | (iv) | |
| A | F | F | T | T |
| B | T | T | F | F |
| C | F | T | F | T |
| D | T | T | F | T |
