10th Class Physical Sciences - Important 2 Marks Questions with Answers
పశ్చిమ గోదావరి జిల్లా ఏలూరు కు చెందిన భౌతిక, రసాయన శాస్త్రముల ఉపాధ్యాయులు శ్రీ గణేష్ గారు పదవ తరగతి చదువుతున్న విద్యార్ధినీ విద్యార్ధులకోసం కనీసం పాస్ కావడానికి సహకరించే, 2 మార్కుల విభాగానికి, 1 మార్కు విభాగానికి ఉపయుక్తమైన చక్కని ప్రశ్నలు - సమాధానాలను రూపొందించి అందించడం జరిగింది. జస్ట్ రెండు పేజీలలో ప్రింట్ తీసుకోవడానికి వీలుగల ఈ ప్రశ్నలు - సమాధానాలు
పిడిఎఫ్ ను డౌన్ లోడ్ చేసుకోవడానికి ఇక్కడ క్లిక్ చేయండి.
1) Why dog’s pant
during hot summer days using the concept of evaporation?
1. Dog didn’t have
sweat glands on its skin except on Its foot pads.
2. On a hot day to
control its temperature it pants, and water evaporates.
3. Evaporation is
a cooling process.
4. so dog pant
during hot summer days.
2)
Why do we get dew on the surface of a cold soft drink bottle kept in open air?
1. The vapour in
the surroundings of cold soft drink bottle condensed into water.
2. so we get the
dew on the surface of a cold soft drink bottle.
3)
Write differences between evaporation and boiling.
Evaporation
|
Boiling
|
1. The conversion of
gas into liquid below its boiling point called evaporation
|
1. The conversion of
gas into liquid at constant temperature called boiling
|
2. No bubbles formed
during evaporation
|
2. Bubbles formed
during evaporation
|
4) Convert 200C into Kelvin scale?
200C + 273 = 293 K
5)
Ask questions to differentiate between evaporation and boiling?
1. What is
boiling?
2. What is
evaporation?
6)
What happens to the water when wet clothes dry?
1. water
evaporates into surroundings whom wet clothes dry.
7)
Equal amount of water is kept in a cap and in a dish, which evaporates faster why?
1. water in a dish
evaporates faster
2. Because its
surface area is more than a cap
8)
What role does specific heat play in keeping watermelon cool for a long time
after removing it from a fridge on a hot day?
1. Watermelon
contains more percentage of water.
2. Specific heat
of water is high; it takes more time to loose it’s coolness.
9)
What is a neutralization reaction? Give two examples.
1. When acid react
with base, it gives salt and water called neutralization reaction.
Example: NaOH +
HCl à
NaCl + H2O
KOH + HCl à
KCl + H2O
10)
What happens when an acid (or) base mixed with water?
1. when acid (or)
base mixed with water it splashes out
2. when water is
mixed with acid (or) base it will be diluted.
11)
Why does tooth decay starts when pH of mouth is lower than 5.5?
1. Tooth enamel
made up of calcium phosphate.
2. When pH of
mouth lower than 5.5 it will be corded then tooth decay starts.
12)
Why doesn’t distilled water conduct electricity?
Distilled water
doesn’t have ions, so they don’t conduct electricity.
13)
Why pure acetic acid doesn’t conduct electricity
Pure Acetic acid
doesn’t have ions. so, it doesn’t conduct electricity.
14)
Plaster of Paris should be stored in moisture proof container. Explain why?
When water is
added plaster of Paris turns into hard solid mass called Gypsum. So, it should
be stored in moisture proof container.
15)
How does the flow of acid rain into a river make the survival of aquatic life
in a river difficult?
1. If the pH of rainwater
less than 5.6 it is called acid rain.
2. Living
organisms can survive only in a narrow range of pH change
3. When acid rain
flows into river aquatic animals’ survival will be difficult
16)
What is baking power? How does it make the cake soft and spongy?
1. Baking power is
a mixture of baking soda and tartaric acid.
2. When baking
power heated (or) mixed with water it produces CO2
3. CO2
will make cake soft and spongy.
17)
Give two important uses of washing soda and baking soda?
Uses of Baking
soda:
1. Used to make
baking power
2. Used in making
antacid tablets.
Uses of Washing
Soda:
1. Used as
cleaning agent in domestic purposes
2. Used in soap,
glass and paper industries.
18)
what is electronic configuration?
The arrangement of
electrons in shells, subshells, orbitals called electronic configuration.
19)
What is nlx method? How it is useful?
1. nlx
method is used to write electronic configuration
2. n – principle
quantum number; l – azimuthal quantum number, x – number of electrons.
20)
What is an emission spectrum?
when an atom of an
element excited it emits a colour of specific wavelength called emission
spectrum.
21)
What is an absorption spectrum?
When an atom of an
element excited in presence of white light it absorbs a light of specific wavelength
called absorption spectrum.
22)
Give example for Dobereiner triodes?
1. Li, Na, K 2. Cl, Br, I
23)
What is Mendeleeff’s periodic law?
The physical and
chemical properties of the elements are periodic functions of their atomic
weights.
24)
What is modern periodic law?
The physical and
chemical properties of the elements are periodic functions of their electronic
configurations.
25)
What is Atomic Radius?
The distance from
the nucleus of atom to the Outermost shell called atomic radius.
26)
What is ionization energy?
The energy
required to remove an electron from the outermost orbit or shell of a neutral gaseous
atom is called ionization energy.
27)
What is octet rule?
Every element
tries to get eight electrons in it’s outermost shell called octet rule.
28)
What is Difference between valence electrons and Covalency?
Valence electrons:
The number of electrons in the outermost shell of an atom.
Covalency: The
number of covalent bonds formed by an atom.
29)
Silver is a better conductor of electricity for conduction of electricity.
Silver is costlier
than copper. So, we prefer copper to Silver.
30)
Why do we use fuses in household circuits?
1. When the
current drawn from main exceeds the max limit 20 A called over loading.
2. When fuse is
added household circuit it will melt when current exceeds 20 A to save the
devices in our houses.
31)
What is Lenz’s law?
The induced
current set up in the coil in such a direction that it opposes the changes in
the flux.
32)
What happens if we connect electrical appliances in the household circuits in
Series?
1.
Electrical appliances in the household circuits are connected in parallel.
2.
If they connected in Series, when one of the resistors in series break down,
the circuit becomes open and current don’t flow in the circuit
33) Why do we consider tungsten as suitable material
for making the filament of a bulb?
1.
Tungsten has high resistivity and high melting point.
2.
So it is used in the making of filament of a bulb
34) Are the head lights of a car connected in series
or parallel why?
1.
The head lights of car are connected in parallel.
2.
If they connected in Series one of them failed to work another one also stop to
work.
35) Why is it difficult to shoot a fish swimming in
water?
1.
Due to refraction the fish appears to be raise in the water.
2.
So we can’t judge the actual position of fish to shoot it.
36) Refractive index of glass relative to water is
9/8. What is the refractive index of water relative to glass?
Answer
is 8/9
37) What is the reason behind the shining of diamonds
and how do you appreciate it?
1.
Total internal refraction is the main reason for shining of diamonds
2.
The critical angle of diamond is very low (24.4) so if a light ray enters into
diamond, it is very likely to undergo total internal reflection.
3.
So I appreciate the scientific reason behind brilliance of diamonds.
38) Why do starts appear twinkling?
1.
The light from the stars undergo multiple refractions through the layers of
atmosphere.
2.
So starts appear twinkling.
39) A man wants to get a picture of zebra. He photographed
a white donkey after fitting a glass with black stripes on the lens of his
camera. What photo will he get explain?
He
will get a photo of donkey with less brightness.
40) Write lens maker’s formula? explain.
here
f – focal length of lens
n
– refractive index of the material of lens
R1,
R2 – radii of curvatures.
41) Explain the reason for blue colour of sky?
1.
Scattering is the phenomenon involved in blue colour of sky.
2.
Oxygen, Nitrogen in our atmosphere scatters blue colour more than other colours
so sky appears blue in colour.
42) How do you appreciate the working of ciliary
muscles in the eye?
1.
Ciliary muscles help us to get image exactly on retina wherever the object is.
2.
It adjusts our eye lens depending on objects distance called accommodation.
3.
So I appreciate ciliary muscles.
43) Why does the picture distorted when a bar magnet
is brought close to the screen of a television?
1.
The magnetic field affects the motion of electrons.
2.
So the picture distorted when a bar magnet is brought close to the screen of a
television.
44) Give few applications of Faraday’s law of
induction in daily life?
1.
in security checkups
2.
in tape recorders
3.
For working of ATM cards.
4.
For working of Induction Stove.
Faraday’s
law of induction will be used in daily life.
45) List three metals that are found in nature in free
state (or) uncombined form?
Gold,
Silver, Copper
46) Write the names of any two ores of Iron?
Haematite,
Magnatite
47) What is the difference between Roasting and
Calcination?
Roasting
is a process of heating ore in presence of oxygen.
Calcination
is a process of heating ore in absence of air.
48) Magnesium is an active metal. If it occurs as
chloride in nature, which method of reduction is suitable for its extraction?
Electrolysis
49) What is activity Series? How it helps in
extraction of metals?
1.
Arranging metals in the descending order of their reactivity called activity
series.
K, Na, Ca, Mg, Al, Zn,
Fe, Pb, Cu
2.
By this series we can choose the process of material’s extraction.
50) What is thermite process? Mention its applications
in daily life?
1.
Highly reactive metals displace metals of lower reactivity from their compound
called thermite process.
2.
This method is used to join railing of railway tracks or cracked machine parts.
51) Name the simplest Hydrocarbon?
Methane
(CH4)
52) What are the general molecular formulae of
alkanes, alkenes, Alkynes?
Alkanes:
CnH2n+2
Alkenes:
CnH2n
Alkynes:
CnH2n-2
53) Name the product other than water formed on
burning of ethanol in air?
Carbon
Dioxide (CO2)
54) What do we call self-linking property of carbon?
If
an element forms bonds between its own atoms to give big molecules called
catenation.
55) Name the compound formed by heating ethanol at
443K with excess of Con. H2SO4?
Ethylene
(C2H4)
56) Give the names of functional groups 1. – CHO 2. C=O
1.
– CHO : Aldehyde
2.
C=O
: Ketone
57) Name the acid present in Vinegar?
Acetic
acid or Ethanoic acid
58) What happens when small piece of sodium is dropped
into ethanol?
it
liberates Hydrogen gas.
59) Define the terms 1. Gangue 2. Slag.
1.
Gangue: the unwanted impurities like sand and clay in the ore called gangue.
2.
Slag: when flux is reacted with Gangue it given slag.
60) What is the lens formula
Prepared by
Sri N Ganesh Sir
School Assistant in
Physical Sciences
Eluru, West Godavari
District.
6:50 pm
