Question

Class - X
Total MaKOV
Sub - Science
Time- 3 hours
General instructions - All Questions are compulsory. Question numbers 1 to 20 are one mark questions. Question
number 21 to 30 are three marks questions. Question number 30 to 35 ore five marks question.
Which of the following salts does not contain water of crystallisation?
a) blue vitrol b) washing soda c) baking soda d) gypsum
Calcium phosphate is present in tooth enamel its nature is
a) basic b) acidic c) neutral d) amphoteric
Which one of the following metais does not react with cold as well as hot water?
a) Na b) ca c) Fe d) Mg
Spinal cord originates from
a) cerebrum b) medulla c) cerebellum d) pons
Which of the following is not an involuntary action?
a) vomiting b)salivation c) heartbeat d) chewing
The main constituent of biogas is
a) methane b) butane c) carbon dioxide d) hydrogen
Fuel used in thermal power plants is
a)water b) uranium c) biomass d) fossil fuels
pH of a gastric juices released during digestion is
a) less than 7 b) more than 7 c) equal to 7 d) equal to 0
how many 176 ohm resistors in parallel are required to carry 5 A on a 220 v line?
b) 4
c)6
What is the maximum resistance which can be made using five resistors each of 1/5 ohm?
a)1/25 b)1/5
What is Aqua regia?
12) Write the principle of an electric generator?
13) What are amphoteric oxides?
14) What is geothermal energy?
Why is sodium kept immersed in kerosene?
We have three resistors containing 3 ohms each. To get a resistance of 2 ohm how should we connect them?
What is the colour of the insulation of live wire and earth wire?
18) Write the chemical equation for the reaction between iron metal and steam.
19) Write a functional difference between arteries and veins.
20) Define negative phototropism?
Write the properties of ionic compounds. Show the formation of Na20 by the electron dot structure.
Write one example for each of the decomposition reaction carried out with the help of
a) electricity b) heat C) sunlight
OR)
a) Can oxidation or reduction takes place alone. Give reason.
b) What is redox reaction? Magnesium ribbon is burns are burns in air with a dazzling flame
Is magnesium oxidised or reduced?
a) 5
08
c)5
15
16
21)
22)
amad
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Answer 1

Answer:

waaaaaah !!.......................

Answer 2

Answer:formula of parallel combination=1/R=1/R1+1/R2+....+1/Rn

1/Rt=1/R1+1/R2+1/R3+1/R4+1/R5

1/Rt=1/1+1/1+1/1+1/1+1/1

1/Rt=5/1

Rt=1/5

Rt=0.2ohm