The Human Eyes And The Colourful World — Science STD 10 — Question

The diagram given alongside shows a ray of light entering a rectangular block of glass:

1. Copy the diagram and draw the normal at the point of entry.
2. Draw the approximate path of the ray of light through the glass block and out of the other side.

In an experiment to study the relation between the potential difference across a resistor and the current through it, a student recorded the following observations:

Potential V (volts)	1.0	2.2	3.0	4.0	6.4
Current I (ampere)	0.1	0.2	0.6	0.4	0.6

On examining the above observations the teacher asked the student to reject one set of readings as the values were out of agreement with the rest. Which one of the above sets of readings can be rejected? Calculate the mean value of resistance of the resistor based on the remaining four sets of readings.

If 25 atomic mass units (u) of a radioactive material are destroyed in a nuclear reaction, how much energy is released in MeV?

why cannot fertilisation take place in flowers if pollination does not occur?

What are sexually transmitted diseases? Give two examples of sexually transmitted diseases.

State difference between the wire used in the element of an electric heater and in a fuse wire.

A salt X when dissolved in distilled water gives a clear solution which turns red litmus blue. Explain the phenomenon.

Describe the process of fertilisation in a flower with the help of labelled diagrams.

If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring? Justify your answer.

In which asexual reproduction two individuals are formed from a single parent and the parental identity is lost? Draw the initial and the final stages of this type of reproduction to justify your answer. Write the event with which this process starts.