The commonly used gas for cooking purpose is LPG. Two compounds present in LPG are saturated hydrocarbons one of them contains 3 carbons and other contains 4 carbons.

1. Write the moleular formulas of these compounds.
2. What makes these gases exist in liquid state in the gas cylinder?
3. Write balanced chemical equation of the reaction involved by the hydrocarbon having 3 carbon atoms, when it burns with oxygen.

Rita and Pema dropped stone from the top of two different towers standing nearby. Rita dropped the stone of mass 1 Kg. After Is time Pema dropped the stone of mass 1.5 Kg which reached the ground 0.46s later than the Rita's stone. If the tower from where Rita dropped the stone is 60 m high, what is the height of tower from where Pema dropped the stone?

Image formed by three different lenses A, B and C and their natures are given in the table below.

1. Which of two lenses among them can be used in the remedy of long sightedness?
2. Draw a ray diagram for the image formed assuming 3 cm focal length of lens B.
3. Write the nature of image formed by the lens C when object is kept at 2F of it.

After the cross-fertilization between long winged (LL) and short winged (ll) drosophila upto 2$^{nd}$ generation were studied. A part of the study is given in the table alongside.

1. What type of characters were there in the parents of the offspring shown in table?
2. Write genophytic ratio of this generation?
3. In the drosophila having Ll, there are the factors of both the characters but only one character is expressed. Clarify the cause.
4. Draw a chart for offspring obtained by crossing between the drosophila of hybrid and the recessive character.

In what ways, the modern periodic table is more advanced than Mendeleev's periodic table? Mention any two points. Write two differences between p-block and s-block elements.

Magnesium is burnt in nitrogen. Which of the following equation is correct for the reaction?

To find the upper fixed point of new thermometer, four students did the following activities. Who can find the correct upper fixed point?

Which one is correct for A in the given diagram?

Which one is the way to increase the magnitude of induced emf in a generator?

What amount of current can flow in the kettle written with 750 watt and 220 V?