P-1 Periodic Classification of Element — Science STD 10 — Question

From Newton’s law of gravitation, derive the formula for the acceleration due to gravity

A, B and C are three common STDs. A and C are caused by bacteria whereas B is caused by a virus D. The virus D reduces the immunity of the infected person to such a low level that the person can die of even very mild diseases.

1. What could A and C be?
2. What is B?
3. Name the virus D?
4. How can A, B and C be caused?
5. Out of A, B and C, which one does not have a definite cure as yet?

What is forest fire? What is its effect on environment?

How much time a satellite in an orbit at height 35780 Km above earth's surface would take, if the mass of the earth would have been four times its original mass?

A potted plant is growing in a transparent glass jar. In this plant, X and Y are the two growing parts having a lot of meristematic tissue. It is observed that the part X of this plant exhibits positive geotropism but negative phototropism. On the other hand, part Y of this plant exhibits negative geotropism but positive phototropism.

1. Name the part X of plant.
2. Name the part Y of plant.
3. Which part of the plant, X or Y, will exhibit positive hydrotropism?
4. Which part of the plant, X or Y, can have tendrils on it?
5. Which phytohormone causes the part X to exhibit negative phototropism?

An electric circuit consisting of a 0.5m long nichrome wire XY, an ammeter, a voltmeter, four cells of 1.5V each and a plug key was set up.

1. Draw a diagram of this electric circuit to study the relation between the potential difference maintained between the points ‘X’ and ‘Y’ and the electric current flowing through XY.
2. Following graph was plotted between V and I values:

What would be the values of ratios when the potential difference is 0.8V, 1.2V and 1.6V respectively? What conclusion do you draw from these values?

3. What is the resistance of the wire?

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?

Explain the glycolysis in detail.

The following diagram shows a part of the periodic table containing first three periods in which five elements have been represented by the letters a, b, c, d and e (which are not their chemical symbols):

1. Select the letter which represents an alkali metal.
2. Select the letter which represents a noble gas.
3. Select the letter which represents a halogen.
4. What type of bond is formed between a and e?
5. What type of bond is formed between d and e?

The germ cell A produced by a person X is round in shape and it fuses with another germ cell B having a long tail and produced by a person Y. The fusion of A and B produces a new cell C. The cell C divides repeatedly and grows inside the organ D of person X to form E in which the body features of the unborn baby are not much developed. E grows further to form F in which the various body features of the unborn baby (like hands, legs, head, eyes, and ears, etc.) can be identified. F grows further and ultimately forms a baby. What are A, B, C, D, E and F? Out of the two persons X and Y, which one is male and which one female?