Science
Choose the correct option for the colour of rays for A and B.
| Colour of Ray A | Colour of Ray B | |
|---|---|---|
| A. | Blue | Red |
| B. | Green | Yellow |
| C. | Red | Violet |
| D. | Violet | Indigo |
options
- A
- B
- C
- D
Answer
C
Reason — In a glass prism, white light disperses into its colours since violet has the highest refractive index in glass so it deviates the most, while red has the lowest refractive index so it deviates the least toward the base of the prism.
In the diagram, ray B emerges closer to the base (more deviated), so it is violet and ray A is less deviated and therefore it is red.
Related Questions
In snails individuals can begin life as male and depending on environmental conditions they can become female as they grow. This is because
options
- Male snails have dominant genetic makeup.
- Female snails have dominant genetic makeup.
- Expression of sex chromosomes can change in a snail’s life time.
- Sex is not genetically determined in snails.
In the following cases, a ray is incident on a concave mirror. In which case is the angle of incidence equal to zero?
options
- A ray parallel to the principal axis.
- A ray passing through the centre of curvature and incident obliquely.
- A ray passing through the principal focus and incident obliquely.
- A ray incident obliquely to the principal axis, at the pole of the mirror.
Identify the incorrect statement
‘The energy available to the producers is maximum’ because:
options
- It is the first trophic level which absorbs 1% of light energy directly from the source.
- It utilizes the most of the chemical energy for its own respiration, growth, reproduction, movement etc.
- It utilizes 10% of light energy and transfers the rest to the next trophic level.
- It transfers only 10% of light energy to the next trophic level
Which of the following is not a role of decomposers in the ecosystem?
options
- Natural replenishment of soil.
- Enrichment of oxygen in atmosphere.
- Waste decomposition.
- Break-down of dead remains.