Electricity — Science STD 10 — Question

1. A person cannot read newspaper placed nearer than 50 cm from his eyes. Name the defect of vision he is suffering from. Draw a ray diagram to illustrate this defect. List its two possible causes. Draw a ray diagram to show how this defect may be corrected using a lens of appropriate focal length.
2. We see advertisements for eye donation on television or in newspapers. Write the importance of such advertisements.

1. Write the function of each of the following parts of human eye:

CORNEA; IRIS; CRYSTALLINE LENS; CILIARY MUSCLES.

2. Millions of people of the developing countries of world are suffering from corneal blindness. These persons can be cured by replacing the defective cornea with the cornea of a donated eye. A charitable society of your city has organised a campaign in your neighbourhood in order to create awareness about this fact. If you are asked to participate in this mission how would you contribute in this noble cause?

1. State the objective of organising such campaigns.
2. List two arguments which you would give to motivate the people to donate their eyes after death.
3. List two values which are developed in the persons who actively participate and contribute in such programmes.

What is lymphatic system? What are its functions?

With a schematic diagram, explain the overall process of respiration.

What is vegetative propagation? List with brief explanation three advantages of practising this process for growing some types of plants. Select two plants from the following which are grown by this process:
Banana, Wheat, Mustard, Jasmine, Gram.

Give the basic features of the mechanism of inheritance.

When do we consider a person to be myopic or hypermetropic? Explain using diagrams how the defects associated with myopic and hypermetropic eye can be corrected?

When we touch a hot plate unknowingly, then this heat is sensed by a receptor P present in our fingers. The receptor triggers and impulse in neuron Q which transmits the message to an organ R which is a part of the central nervous system. Here the impulse is passed on to a neuron S which in turn passes it to a yet another neuron T. The neuron T passes the impulse to a tissue U in our arm. The tissue U then contracts and pulls our hand away from the hot plate.

1. What is the name of (i) receptor P (ii) neuron Q, and (iii) organ R?
2. What is (i) neuron S, and (ii) neuron T?
3. Name the tissue U.
4. What name is given to the phenomenon in which hand is pulled away quickly from the hot plate?
5. Name the effector in this whole process.

Solution A turns universal indicator blue to purple whereas solution B turns universal indicator orange to red.

1. What will be the action of solution A on litmus?
2. What will be action of solution B on litmus?
3. Name any two substances which can give solutions like A.
4. Name any two substances which can give solutions like B.
5. What sort of reaction takes place when solution A reacts with solution B?