The document discusses 30 multiple choice questions about various science topics. It provides the question, four possible answers, and then explains the correct answer. The topics covered include states of matter, atomic structure, carbon allotropes, electronic configurations, carbon forms, hydrogen bonding, gas identification, heat capacity, monoatomic ions, bee stings, fuses, bat echolocation, sound waves, balloon buoyancy, electromagnetic induction, lens images, Van de Graaff generators, short circuits, refraction, semiconductors, cellular respiration, sexually transmitted diseases, dengue fever, species abundance, iron/folic acid supplements, mustard oil adulteration, silkworm plants, honey sugars, cell constituents, and lepro

2. ANSWER
01. The latest discovered state of matter is
Solid
 Bose-Einstein condensate
 Plasma
 liquid
(c) There are four states of matter, which are given
solid, liquid, gas and plasma. Plasma is the latest
discovered state of matter. This state of matter exists at
very high temperature.

3. ANSWER
02. The mass number of an atom is determined
by
adding the number of neutrons and number of electrons
 adding the number of protons and number of electrons
 the number of protons only
 adding the number of neutrons and number of protons
(d) Mass number is defined as the sum of the number of
protons and neutrons in an atom of the element. It is
denoted by A. A=p+n
where, p = number of protons n = number of neutrons

4. ANSWER
03. Which one of the following statements is
correct?
Fullerenes have only six-membered carbon rings
 Fullerenes are cage-like molecules
 Diamond is thermodynamically the most stable allotropof carbon
 Graphite is slippery and hard and is therefore, used as a dry lubricant in machines
(b) Fullerenes consist of 20 hexagonal and 12 pentagonal
rings. They are the cage-like molecules. Diamond is
kinetically most stable allotrope of carbon. Graphite is soft,
smooth and slippery and is therefore, used as a dry lubricant
in machines

5. ANSWER
04. Which one of the following is the correct
electronic configuration of chlorine?
 2, 7, 8
 2, 8, 7
 2, 8, 8
 7, 8, 9
(b) We know that, Atomic number of chlorine = 17 So,
its electronic configuration = 2, 8, 7.

6. ANSWER
05. The most stable form of carbon is
 diamond
 graphite
 fullerene
 coal
(a) The most stable form of carbon is diamond because
in its structure, directional covalent bonds are present
throughout the lattice.

7. ANSWER
06. The high heat of vaporisation of water
is mainly a result of
van der Waals’ forces
 covalent bonds
 interionic attraction
 hydrogen bonding
(d) The heat of vaporisation is often quoted for the normal
boiling temperature of the substance. In the molecule of
liquid, water are held together by relatively strong hydrogen
bonding. High value of heat of vaporisation shows the
presence of stronger forces of attraction.

8. ANSWER
07. A sample of gas is to be identified by means of its behaviour in
the presence of a glowing splint. Which of the following gases will
neither itself burn nor cause the splint to burn
Oxygen
 Nitrogen
 Hydrogen
 Methane
(b) Nitrogen is an inert gas neither itself burn nor cause the
splint to burn. Oxygen does not burn itself but act as a
supporter of combustion. Hydrogen helps in producing
flames, whereas methane helps in combustion and readily
produces carbon dioxide.

9. ANSWER
08. Heat given to a body which raises its
temperature by 1°C is known as
water equivalent
 thermal capacity
 specific heat
 temperature gradient
(b) The heat capacity of a body is the quantity of heat
required by the body to raise its temperature by 1°C. It
is also termed as thermal capacity.

10. ANSWER
09. A monoatomic species that has 18
electrons and a net charge of 2− has
the same number of electrons as a neutral argon atom
 more protons than electrons
 2 unpaired electrons
 20 protons
(a) A monoatomic species has the same number of
electrons as a neutral argon atom.

11. ANSWER
10. The burning sensation of a bee sting can be
stopped by rubbing the affected area with soap.
This is because
 a bee sting is acidic and soap, an alkali, neutralises it
 a bee sting is alkaline and soap, an acid, neutralises it
 soap cleans the affected area and removes the sting
 soap acts as an anaesthetic and dulls the sensation
(a) Bee sting contains formic acid which leads to high
burning sensation when bites. By placing large amount
of alkali near the sting site is unlike to produce a
perfectly neutral pH to stop the burning sensation.

12. ANSWER
11. A fuse is used in an electric circuit to
 break the circuit when excessive current flows through the
circuit
 break the circuit when power gets off
 indicate if the current is flowing uninterrupted
 complete the circuit for flow of current
(a) A fuse is a metal wire or strip of low resistance that
melts when too much current flows through it. It is used
in an electric circuit to break the circuit when excessive
current flows through the circuit.

13. ANSWER
12. Which one among the following waves bats
use to detect the obstacles in their flying path?
 Infrared waves
 Electromagnetic waves
 Ultrasonic waves
 Radio waves
(c) Ultrasonic waves are used by bat to detect the
obstacles in their flying path. It is an oscillating sound
pressure wave with a frequency greater than the upper
limit of the human hearing range.

14. ANSWER
13. Sound waves are similar to the waves
 of laser light passing through air
 generated in a stretched wire by hitting or plucking the wire
 generated in a pipe filled with air by moving the piston
attached to the pipe up and down
 generated by the mobile phone towers
(c) Sound waves are similar to the waves generated in a pipe filled
with air by moving the piston attached to the pipe up and down.
Sound waves are longitudinal waves. Waves generated in the pipe
filled with a piston are also longitudinal wave associated with laser
light, stretched wire and mobile phones are of transverse nature.

15. ANSWER
14. A balloon filled up with gas would only go
up in air it is filled up with
 a gas whose density is lower than air
 a gas whose density is higher than air
 cold air
 water vapour
(a) The balloon will go up, if it is filled up with a gas whose density
is lower than air. Cold air and water vapour are having densities
higher than air. Therefore weight of balloon will be more in
comparison with buoyant force (lifting force) which causes the
balloon to go down instead of rising up.

16. ANSWER
15. The phenomenon of electromagnetic
induction implies a production of induced
 resistance in a coil when themagnetic field changes with time
 current in a coil when an electricfield changes with time
 current in a coil when a magnetic field changes with time
 voltage in a coil when an electricfield changes with time
(c) When magnetic field associated with a coil changes,
magnetic flux associated with the coil also changes. This change
of magnetic flux induces an emf in the coil which is called
electromagnetic induction. This emf results a current through
the coil.

17. ANSWER
16. While looking at an image formed by a convex lens (one
half of the lens is covered with a black paper), which one of
the following will happen to the image?
 Half of the image will be visible.
 Intensity of the image will be diminished.
 Image will be inverted now.
 One can see an image of smaller size.
(b) When half of the lens is covered with a black paper. Light
passes through remaining half part of the lens only. Therefore,
intensity of the image will redue to half of the initial intensity, i.e.
intensity of the image will be diminished. Position on size of the
image remains unaffected.

18. ANSWER
17. Van de Graaff generator is used for
 accelerating charged particles
 generating large currents
 generating electric field
 generating high frequency voltage
(d) Van de Graaff generator is used for generating high frequency
voltage. A Van de Graaff generator is an electrostatic generation
which uses a moving belt to accumulate very high amounts of
electrical potential on a hollow metal globe on the top of the stand.
It was invented by American Physicist Robert J. Van de Graaff in
1929

19. ANSWER
18. During short-circuiting, the current flowing
in the electrical circuit
 reduces substantially
 does not change
 increases instantaneously
 varies continuously
(a) A short-circuited path offers very low resistance or
almost zero resistance to the flow of current. Therefore,
current follows the short-circuited path and current
through the mains electrical circuit reduces substantially.

20. ANSWER
19. In optical instruments, the lenses are
used to form image by the phenomenon of
 reflection
 refraction
 scattering
 diffusion
(b) In optical instruments like microscope and telescope,
two lenses are used. One of the lenses is called objective
and the other is called eyepiece. Both these lenses form
images by the phenomenon of refraction.

21. ANSWER
20. A semiconducting device is connected in a series circuit with a battery and a
resistance. Current is found to pass through the circuit. If the polarity of the battery is
reversed, then the current drops to zero. The device may be
 p-type semiconductor
 n-type semiconductor
 an intrinsic semiconductor
 p-n junction
(d) Given characteristics of current through a semiconducting
device is in accordance with a diode or p-n junction. In one polarity
of the battery p-n junction is forward biased and current passes
through the circuit. If the polarity of the battery is reversed, p-n
junction becomes reverse biased and current drops to zero.

22. ANSWER
21 .The site of cellular respiration in animal
cell is
 ribosome
 mitochondria
 endoplasmic reticulum
 lysosome
(b) Mitochondria is the site of cellular respiration in animal
cell. They carry out oxidation of food and transfer the
energy to ATP (used to bring about energy requiring
activities of the cell). The mitochondria are thus often
described as the powerhouse or ATP mills of the cell.

23. ANSWER
22. Which one among the following is not a
sexually transmitted disease?
 Syphilis
 Gonorrhea
 Scurvy
 Hepatitis-B
(c) Scurvy is not a sexually transmitted disease. It is a deficiency
disease that occurs due to lack of vitamin-C. Its symptoms include
bleeding gums, weakness, anaemia, etc. Sexually transmitted diseases
are infections that spread primarily through person to preson by sexual
contact, e.g. syphilis, hepatitis-B, gonorrhea, etc.

24. ANSWER
23. What is ‘breakbone fever’ most commonly
known as?
 Typhoid
 Rhinitis
 Yellow fever
 Dengue
(d) Dengue fever, also known as breakbone fever, is a
mosquito-borne tropical disease caused by the dengue
virus. Its symptoms include fever, headache, muscle and
joint pains and a characteristic skin rash that is similar to
measles.

25. ANSWER
24. Which one among the following groups is the most
abundant in terms of number of species identified
 Fungi
 Green plants
 Bacteria
 Insects
(d) Insects are largest group in terms of number of
species identified. Insects belong to phylum–
Arthropoda.

26. ANSWER
25. After diagnosis of disease in a person, the doctor
advises the patient iron and folic acid tablets. The
person is suffering from
 osteoporosis
 anaemia
 goitre
 protein-energy malnutrition
(b) Anaemia is a condition in which the body lacks enough
healthy red blood cells or haemoglobin. It is mainly caused
due to the deficiency of minerals and vitamins in the body.
So, in this case, doctor prescribes iron and folic acid tablets
to the anaemic person (Folic acid is a form of vitamin-B).

27. ANSWER
26. Dropsy is a disease caused due to
adulteration in
 ghee
 arhar dal
 mustard oil
 turmeric powder
(c) Dropsy is an abnormal collection of fluid in any part of
the body. It is usually caused due to the adulteration of
mustard oil with Argemone oil. Ghee, arhar dal and
turmeric powder do not cause dropsy when they get
adulterated.

28. ANSWER
27. Leaves of which of the following plants are
not used for the rearing of silkworms?
 Mulberry
 Castor
 Oak
 Teak
(d) Teak plant is not used for rearing silkworms. Culture of silkworm is
known as sericulture. Silk is obtained from cocoon of silkworm which
represent pupa stage. The scientific name of silkworm is Bombyx mori. Silk is
first produced in China. Silk is made up of fibrin protein. Silkworm is most
commonly reared on mulberry, oak and castor plants.

29. ANSWER
28. In honey, which one among the following
sugars predominates?
 Sucrose
 Fructose
 Galactose
 Maltose
(b) Fructose is the predominant sugar nearly 38.5% in
the honey. Beside it, other contents are glucose,
enzymes, proteins, vitamins and minerals.

30. ANSWER
29. Within an animal cell, the most abundant
inorganic constituent of protoplasm is
 sodium and potassium salt
 water
 iron
 phosphate
(b) Inorganic constituents of protoplasm is comprised of
water, various salts, gases, etc. Of these, water forms the
main medium in which various metabolic processes are
carried out. It is comprised of about 90% of the protoplasm.

31. ANSWER
30. Leprosy is caused by
 virus
 bacteria
 protozoan
 retrovirus
(b) Leprosy is caused by the bacterium Mycobacterium
leprae, which has a long incubation period. This microbe
mainly affects the skin and peripheral nerves. Leprosy is not
highly infectious. It is transmitted through droplets from
nose and mouth.