ras pre science one liners by mukta rao pt 1

Question 1

who discovered the light spectrum

Answer 1

newton

Question 2

who discovered the phenomenon of scattering of light

Answer 2

cv raman

Question 3

when was the phenomenon of scattering of light discovered

Answer 3

on 28 feb 1928 by cv raman

Question 4

which day is observed on 28 feb and why

Answer 4

science day
on 28 feb 1928 cv raman discovered scattering of light phenomenon

Question 5

which light scatters most and least

Answer 5

max violet
min red

Question 6

why are the danger signs red

Answer 6

red scatters the least

Question 7

how tall a mirror would be needed for a complete image

Answer 7

half of the height of object

Question 8

near sightedness name

Answer 8

myopia

Question 9

far sightedness name

Answer 9

hypermatopia

Question 10

which lens is used in myopia

Answer 10

concave

Question 11

which lens is used in hypermatopia

Answer 11

convex

Question 12

where is image formed in myopia

Answer 12

before retina thus concave pushes the image forward

Question 13

where is image formed in hypermetropia

Answer 13

after retina thus convex pulls it forward

Question 14

uses of convex mirror?

Answer 14

rearview mirror
mirror to check bottoms of vehicles
street lamps

Question 15

uses of concave mirror

Answer 15

zooming property thus saloons for shaving or dentists

Question 16

formula for salt

Answer 16

NaCl aka sodium chloride

Question 17

which compound is used in powder or cosmetics or ointments

Answer 17

zinc chloride ZnCl2

Question 18

which compound is used for artificial rain

Answer 18

AgI silver iodide

Question 19

which compound is used for voting marker ink

Answer 19

silver nitrate AgNO3

Question 20

why shouldn’t egg be eaten with a silver spoon

Answer 20

sulphur in egg could react with silver and form AgS which is poisonous and also destroys the silver of spoon

Question 21

the 22K gold used for ornaments has what added to gold

Answer 21

either silver or copper

Question 22

which gas is used in tubelights

Answer 22

mercury gas + argon (Ar)

Question 23

formula for bleaching powder

Answer 23

CaOCl2

Question 24

plaster of paris formula

Answer 24

(CaSO4)2.H2o

Question 25

formula for gypsum

Answer 25

(CaSO4).2H2O or CaSO4.2H2o

Question 26

formula for heavy water

Answer 26

D2O

Question 27

uses of hydrogen peroxide

Answer 27

for cleaning wounds and bleaching

Question 28

formula for baking soda

Answer 28

sodium bicarbonate i.e NaHCO3

Question 29

what is the composition of brass

Answer 29

30%Zn and 70%Cu

Question 30

what is the composition of bronze

Answer 30

Cu+Sn (tin and copper)

Question 31

what is the composition of german silver

Answer 31

Zn+Ni+Cu zinc nickel copper NO SILVER

Question 32

composition of steel

Answer 32

iron+cromium+nickel

Question 33

what is present in permanent hardness of water

Answer 33

sulphate and nitrate salts of calcium and magnesium

Question 34

what is present in temporary hardness of water

Answer 34

bicarbonates of calcium and magnesium

Question 35

which acid is vinegar or pickles

Answer 35

acetic acid CH3COOH

Question 36

which element is used in solar cell

Answer 36

cesium

Question 37

which compound is table sugar

Answer 37

sucrose C12H22O12

Question 38

soda water is?

Answer 38

carbonic acid H2CO3 thats why they are called carbonated drinks

Question 39

acid in grapes?

Answer 39

tartric acid also used in making namkeen

Question 40

electric conductance descending order for following: copper aluminium silver tungsten

Answer 40

silver max cu al tn

Question 41

which acid is produced in stomach for digestion of food

Answer 41

HCl

Question 42

what happens to make milk go sour

Answer 42

lactose sugar is converted to lactic acid

Question 43

pH of blood?

Answer 43

7.4

Question 44

where is gravity max and min on earth

Answer 44

max at poles (apprx 10 m/s2) min at equator

Question 45

how much the rotation of earth needs to be increased for gravity to become zero

Answer 45

17 times

Question 46

what is the weight felt by an object during free fall

Answer 46

none free

Question 47

who gave rules for planetary speeds

Answer 47

Johannes Kepler

Question 48

what is the speed of satellite on polar route

Answer 48

08km/second

Question 49

in how much time a polar route satellite completes one revolution around earth

Answer 49

1.24 hours

Question 50

distance of a geostationary satellite from surface is

Answer 50

36000 km

Question 51

what is the direction of revolution of a geostationary satellite

Answer 51

same as earth i.e. west to east