general Science 50 MCQ for Stock assistant wildlife guard by home academy
1. Which chemical is most commonly used forartificial ripening of mangoes in India?
(a) Potassium Iodide
(b) Silver Iodide
(c) Ammonium Nitrate
(d) Calcium Carbide
Answer: (d)
Explanation:
❖ The most commonly used chemical for artificial
ripening is Calcium Carbide (CaC2).
❖ Calcium Carbide is colourless when pure, but
greyish-white to black in colour otherwise, with
garlic like odour. When it reacts with water, it
produces acetylene gas (popularly referred to as
carbide gas) which is an analogue to ethylene and
quickens the ripening process.
2. Presence of which of the following minerals in Banana does make it slightly radioactive?
(a) Sodium
(b) Calcium
(c) Magnesium
(d) Pottasium
Answer: (d)
Explanation:
❖ Bananas are slightly radioactive because they are
rich in potassium, and one of its natural isotopes
(variants) is potassium-40, which is radioactive. A
typical banana contains around 140g of potassium,
of which about 16mg is potassium-40 – making
you 280 times more radioactive than a banana.
3. Who among the following scientists did discoverRadium?
(a) Marie and Pierre Curie
(b) Andre-Louis Debierne
(c) Galileo Galilei
(d) Ada Lovelace
Answer: (a)
Explanation:
❖ Marie and Pierre Curie successfully isolate
radioactive radium salts from the mineral
pitchblende in their laboratory in Paris. In 1898,
the Curies discovered the existence of the
elements radium and polonium in their research of
pitchblende.
❖ Marie Curie was the first woman to win a Nobel
Prize, the first person and the only woman to win
the Nobel Prize twice, and the only person to win
the Nobel Prize in two scientific fields. She was the
first woman to become a professor at the
University of Paris in 1906.
4. Who among the following did give the principle-“Atoms can neither be created nor destroyed”?
(a) Avogadro
(b) Dalton
(c) Rutherford
(d) Niels Bohr
Answer: (b)
Explanation:
❖ John Dalton, a British school teacher, published his theory about
atoms in 1808. His findings were based on experiments and the
laws of chemical combination.
Following are the Postulates given by Dalton-
1. All matter consists of indivisible particles called atoms.
2. Atoms of the same element are similar in shape and mass, but
differ from the atoms of other elements.
3. Atoms cannot be created or destroyed.
4. Atoms of different elements may combine with each other in a
fixed, simple, whole number ratios to form compound atoms.
5. Atoms of same element can combine in more than one ratio to
form two or more compounds.
6. The atom is the smallest unit of matter that can take part in a
chemical reaction.
5. Which among the following is a common salt in Detergents?
(a) Avogadro
(b) Dalton
(c) Rutherford
(d) Niels Bohr
Answer: (a)
Explanation:
❖ Sodium sulfate, used as a filler in detergent powder,
enables the adjustment of the concentration of the
active matter in the detergent, as required.
❖ The chemical formula of detergent is C18H29NaO3S.
6. What is the effect of rusting on the weight of Iron?
(a) Increases for long time
(b) Decreases then increases
(c) Increases then decreases
(d) Remains constant
Answer: (c)
Explanation:
❖ Corrosion is the deterioration of a metal. When a metal
corrodes an oxide will form on the surface exposed to the
corrosive medium and the weight increases because the
oxide is formed by, for example, iron + oxygen Fe2O3 orFe3O4 that weights more than Fe. But this is just one case
of corrosion, there are many different types of corrosion
mechanisms for different materials.
❖ The oxides are not so adherent to the metal surface and
so maybe at first there is an increase in weight but the
final result is a loss of metal and weight.
7. Haematite & Magnetite are the ores of which of the following metals?
(a) Zinc
(b) Iron
(c) Calcium
(d) Manganese
Answer: (b)
Explanation:
❖ Iron ores are rocks and minerals from which metallic iron
can be economically extracted.
The iron is usually found in the form of-
1. magnetite (Fe3O4, 72.4% Fe)
2. Hematite (Fe2O3, 69.9% Fe)
3. Goethite (FeO(OH), 62.9% Fe)
4. Limonite (FeO(OH)·n(H2O), 55% Fe) or siderite (FeCO3,
48.2% Fe).
8. Consider the following statements with reference
to the noble metals of periodic table:
1. Noble metals are found in pure form in nature
2. Uranium and lead are examples of noble metals
Which of the above given statements is/are correct?
(a) 1 Only
(b) 2 Only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (a)
Explanation:
❖ Noble metals are metallic elements that show
outstanding resistance to chemical attack even at high
temperatures. They are well known for their catalytic
properties and associated capacity to facilitate or control
the rates of chemical reactions.
❖ Noble metals comprise- ruthenium (Ru), rhodium (Rh),
palladium (Pd), osmium (Os), iridium (Ir), platinum (Pt),
gold (Au), silver (Ag).
9. Which of the following get corroded by open air
due to oxidation?
1. Iron
2. Copper
3. Zinc
4. Aluminium
(a) 1 and 2
(b) 2 and 3
(c) 1, 2 and 3
(d) All of these
Answer: (d)
Explanation:
❖ Corrosion is a natural process that converts a refined
metal into a more chemically stable form such as oxide,
hydroxide, carbonate or sulfide.
❖ The output of aluminum corrosion is aluminum oxide,
which is a very hard material.
10. Which of the following is the correct general
formula for alkanes group?
(a) CnH2n
(b) CnH2n-2
(c) CnH2n+2
(d) CnHn
Answer: (c)
Explanation:
❖ Alkanes have the general formula CnH2n+2 and can be
subdivided into the following three groups: the linear
straight-chain alkanes, branched alkanes, and
cycloalkanes. Alkanes are also saturated hydrocarbons.
Alkanes are the simplest and least reactive hydrocarbon
species containing only carbons and hydrogens.
11. Which of the following is main component of the
Biogas?
(a) Methane
(b) Ethane
(c) Butane
(d) Propane
Answer: (a)
Explanation:
❖ Biogas is an emerging renewable energy source which is
obtained through degradation of organic matter by
bacteria under anaerobic conditions. Raw biogas contains
about 55–65% methane (CH4), 30–45% carbon dioxide
(CO2), traces of hydrogen sulphide (H,S), and fractions of
water vapour.
12. The pH of the human blood is slightly ______.
(a) Acidic
(b) Basic
(c) Neutral
(d) None of these
Answer: (b)
Explanation:
❖ Blood is normally slightly basic, with a normal pH range
of about 7.35 to 7.45. Usually, the body maintains the pH
of blood close to 7.40.
❖ The pH stands for “potential hydrogen” in any solution.
pH scale measures the concentration of hydrogen ions in
a certain solution. Consequently, a number is assigned to
it. The higher the concentration of hydrogen ions, the
lower would be the pH.
13. Which of the following is the main preservative
used in food items?
(a) Citric Acid
(b) Potassium Chloride
(c) Sodium Benzoate
(d) Sodium Chloride
Answer: (c)
Explanation:
❖ Sodium benzoate is a preservative, with the E number
E211. It is most widely used in acidic foods such as salad
dressings (i.e. acetic acid in vinegar), carbonated drinks
(carbonic acid), jams and fruit juices (citric acid), pickles
(acetic acid), condiments.
14. The atoms, in which the number of protons is
same but the number of neutrons is different, are
known as-
(a) Isobars
(b) Isomers
(c) Isotones
(d) Isotopes
Answer: (d)
Explanation:
❖ Isotopes are atoms of the same element that have
different numbers of neutrons but the same number of
protons and electrons. The difference in the number of
neutrons between the various isotopes of an element
means that the various isotopes have different masses.
❖ For example, among the hydrogen isotopes, deuterium
(denoted as 2H or D) has one neutron and one proton.
This is approximately twice the mass of protium (1H),
whereas tritium (3H) has approximately three times the
mass of protium.
15. Which of the following is used as non-stick
coating for cooking utensils?
(a) Perspex
(b) Styrofoam
(c) Polystyrene
(d) Teflon
Answer: (d)
Explanation:
❖ A non-stick surface is a surface engineered to reduce the
ability of other materials to stick to it. Non-stick is often
used to refer to surfaces coated with
polytetrafluoroethylene (PTFE), a well-known brand of
which is Teflon.
❖ Teflon coated nonstick fry pans are not safe because they
release toxic fumes when heated above a certain
temperature.
16. The force of friction exerted by the ground on
the two wheels during peddling of a bicycle is such
that it acts
(a) in the backward direction on the front wheel and
in the forward direction on the rear wheel
(b) in the forward direction on the front wheel and in
the backward direction on the rear wheel
(c) in the backward direction on both the wheels
(d) in the forward direction on both the wheels
Answer: (a)
Explanation:
❖ Due to peddling, the point of contact of the rear wheel
has a tendency to move backwards. So frictional force
opposes the backwards tendency i.e., the frictional force
acts in the forward direction. But the back wheel
accelerates the front wheel in the forward direction. To
oppose this frictional force acts in the backward direction
on the front wheel.
17. If a machine is lubricated with oil
(a) the mechanical advantage of the machine increases
(b) the mechanical efficiency of the machine increases
(c) both its mechanical advantage and efficiency increase
(d) its efficiency increases, but its mechanical advantage
decreases.
Answer: (b)
Explanation:
❖ Friction, unabated, can cause many problems for
machinery. When a machine is lubricated with oil friction
decreases.
❖ Proper lubrication facilitates uninterrupted machine
operation and is one of the most important aspects of
machine health and efficiency.
18. If the distance between the earth and the sun
were half its present value, the number of days in a
year would have been
(a) 64.5
(b) 129
(c) 182.5
(d) 730
Answer: (b)
Explanation:
According to Kepler’s law T² ∝ r³
(T₁ / T₂)² = (r₁ / r₂)³
(365 / T₂)² = (2r₁ / r₁)³
(365 / T₂)² = 8
365 / T₂) = 2√2
T₂ = 365 / (2√2)
T₂ = 129 days
There will be 129 days in a year.
19. Heat given to a body which raises its
temperature by 1°C is-
(a) water equivalent
(b) thermal capacity
(c) specific heat
(d) temperature gradient
Answer: (b)
Explanation:
❖ Heat capacity or thermal capacity is a physical
property of matter, defined as the amount of heat to
be supplied to an object to produce a unit change in
its temperature. Heat capacity is an extensive
property.
❖ The SI unit of heat capacity is joule per kelvin.
20. Which of the following parameters does not
characterize the thermodynamic state of matter?
(a) temperature
(b) pressure
(c) work
(d) volume
Answer: (b)
Explanation:
❖ The thermodynamic state of a system is defined by
specifying values of a set of measurable properties
sufficient to determine all other properties. The
thermodynamic variables in case of a gas are
pressure, temperature, and volume in addition to
number of moles.
21. A child swinging on a swing in sitting position,
stands up, then the time period of the swing will
(a) increase
(b) decrease
(c) remains the same
(d) increases if the child is long and decreases if the
child is short
Answer: (b)
Explanation:
❖ The time period will decrease. When the child
stands up, the centre of gravity is shifted upwards
and so the length of swing decreases.
T= 2π√l/g
22. Three sound waves of equal amplitudes have
frequencies (f-1, f, f+1). They superpose to give beats.
The number of beats produced per second is
(a) 2
(b) 1
(c) 4
(d) 3
Answer: (a)
Explanation:
Beat produced between(f-1) and f is 1.
❖ Beat produced between f and f+1 is 1.
❖ Beat produced between(f-1) and (f+1) is 2
∴ No of beats produced per second will be 2
23. If a wire is stretched to make it 0.1% longer, its
resistance will
(a) increase by 0.05%
(b) increase by 0.2%
(c) decrease by 0.2%
(d) decrease by 0.05%
Answer: (b)
Explanation:
Resistance of wire R = ρl/A----------(1)
On stretching, volume (V) remains constant.
So, V = Al or A=V/l
Therefore, R = ρl2/V (Using (1))
Taking logarithm on both sides and differentiating we
get,
ΔR/R = 2Δl/l (Since V and ρ are constants)
(ΔR/R)% = (2Δl/l)%
Hence, when the wire is stretched by 0.1% its
resistance will increase by 0.2%
24. If there are n capacitors in parallel connected to V
volt source, then the energy stored is equal to
(a) CV
(b) (½)nCV2
(c) CV2
(d) (1/2n)CV2
Answer: (b)
Explanation:
Total capacity =nC
∴ Energy =½ nCV2
25. A magnetic needle is kept in a non-uniform
magnetic field. It experiences
(a) a force and a torque
(b) a force but not a torque
(c) a torque but not a force
(d) neither a force nor a torque
Answer: (a)
Explanation:
A magnetic needle is kept in a non-uniform magnetic
field. It will experience force and torque both. Due to
unequal forces acting on the poles, it will experience
torque.
26. Which among the following temperature scale is
based upon absolute zero?
(a) Celsius
(b) Fahrenheit
(c) Kelvin
(d) Rankine
Answer: (c)
Explanation:
The kelvin is the base unit of temperature in the
International System of Units (SI), having the unit
symbol K. The relation between kelvin and celsius
scales is TK = t°C + 273.15. On the Kelvin scale, pure
water freezes at 273.15 K, and it boils at 373.15 K.
27. Radioactive emission of which of the following
particles would change(s) mass number as well as
atomic number?
1. Gamma particle
2. Beta particle
3. Alpha particle
Select the correct option from the codes given below:
(a) Only 1 and 2
(b) Only 2 and 3
(c) Only 3
(d) None of these
Answer: (c)
Explanation:
An Alpha Particles is a helium nucleus, it involves the
loss of 2 protons and 2 neutrons. As a result, the atom
the loses an alpha particle decreases its mass number
by four (2 protons and 2 neutrons) and decreases it's
atomic number by 2 (it loses two protons).
28. Light Emitting Diode (LED) converts
(a) Light energy into electrical energy
(b) Electrical energy into light energy
(c) Thermal energy into electrical energy
(d) Mechanical energy into electrical energy
Answer: (b)
Explanation:
A light-emitting diode (LED) is a two-lead
semiconductor light source that resembles a basic pnjunction diode, except that an LED also emits light.
29. If the number of rotations of earth increases, then
the weight of the objects on its surface—
(a) Will increase
(b) Will decrease
(c) No change
(d) Nothing can be said on this basis
Answer: (b)
Explanation:
The centripetal force required for the circular motion is
obtained by the weight of the object. Similarly, the
centripetal acceleration required for the circular
motion is obtained by the gravitational acceleration,
when the object exhibiting circular motion is situated
on earth’s surface. In this way the effective
gravitational acceleration (g’) of the particle in circular
motion will be—
g'=g-rγω2 cosλ
30. Why red colour is used as an emergency or danger
signal?
(a) It is a striking colour
(b) Its wavelength is the longest
(c) It is scattered
(d) It has very high energy
Answer: (b)
Explanation:
Red is used as an emergency or danger signal as its
wavelength is the longest of the entire color and is able
to travel the longest distance through fog, rain etc.
31. Oxygen transportation in a human body takes
place through
1. Blood
2. Lungs
3. Tissue
The correct sequence of transportation is
(a) 1, 2 and 3
(b) 3, 1 and 2
(c) 2, 1 and 3
(d) 1, 3 and 2
Answer: (c)
Explanation:
As blood passes through the lungs, the haemoglobin
picks up oxygen because of the increased oxygen
pressure in the capillaries of the lungs, and can then
release this oxygen to body cells where the oxygen
pressure in the tissues is lower.
32. Consider the following statement about lymph-
1. Lymph is also a medium of circulation in the human
body.
2. Lymph flows in only one direction - from the heart to
body tissues.
3. Lymph protects the body by killing the germs drained
out of the body tissues with the help of Lymphocytes.
Which of the above given statement(s) is/are correct-
(a) 1 and 3
(b) 1 and 2
(c) 2 and 3
(d) All statements are correct
Answer: (a)
Explanation:
The lymphatic system is a part of immune system and
it has many functions which include
1. protecting body from illness-causing invaders
2. maintaining body fluid levels
3. absorbing digestive tract fats and removing cellular
waste
4. Blockages, diseases or infections that can affect
lymphatic system's function
33. Blue Baby Syndrome is caused by the
contamination of
(a) nitrite
(b) sulphite
(c) nitrate
(d) sulphate
Answer: (a)
Explanation:
❖ Blue baby syndrome, also known as infant
methemoglobinemia, is a condition where a baby’s
skin turns blue. This occurs due to a decreased
amount of hemoglobin in the baby’s blood.
❖ The most common cause of blue baby syndrome is
water contaminated with nitrates.
34. Which among the following is the main
constituent of pearl?
(a) Calcium carbonate
(b) Calcium oxide
(c) Calcium nitrate
(d) Calcium sulphate
Answer: (a)
Explanation:
❖ The main constituents of pearls are Calcium
Carbonate and Magnesium Carbonate.
35. A biological community in its environment such as
a pond, an ocean, a forest, even an aquarium is
known as……………
(a) biome
(b) community
(c) abiotic environment
(d) ecosystem
Answer: (a)
Explanation:
❖ A biome is a large community of vegetation and
wildlife adapted to a specific climate. The five major
types of biomes are aquatic, grassland, forest,
desert, and tundra.
36. Consider the following statements-
1. Once the HIV gains a foothold, it can never be
eradicated from the body.
2. Many HIV patients, however, can manage the
infection with a cocktail of drugs.
Which of the above given statement(s) is/are correct?
(a) Only 1
(b) Only 2
(c) Both (a) and (b)
(d) Neither 1 nor 2
Answer: (c)
Explanation:
❖ HIV (human immunodeficiency virus) is a virus that
attacks the body’s immune system. If HIV is not
treated, it can lead to AIDS (acquired
immunodeficiency syndrome).
❖ The human body can’t get rid of HIV and no effective
HIV cure exists. So, once you have HIV, you have it
for life.
37. Match List-I with List-II
| List-I A. Gonads B. Pituitary C. Pancreas D. Adrenal | List-II 1. Insulin 2. Progesterone 3. Growth hormone 4. Cortisol |
Select the correct answer from the codes given below:
A B C D
(a) 2 3 4 1
(b) 2 3 1 4
(c) 3 2 4 1
(d) 3 2 1 4
Answer: (b)
Explanation:
A. Gonads --Progesterone
B. Pituitary --Growth hormone
C. Pancreas --Insulin
D. Adrenal --Cortisol
38. Hemoglobin in humans has the highest affinity for
which of the following gases?
(a) Methane
(b) Carbon Monoxide
(c) Nitrous oxide
(d) Carbon dioxide
Answer: (b)
Explanation:
Carbon monoxide is a colorless, tasteless, and odorless
gas made by combustion. Breathing in CO can be fatal
because it doesn't allow oxygen to get to your heart
and other organs. It forms carboxyhemoglobin. This
substance is made in blood when hemoglobin
combines with carbon monoxide instead of oxygen.
39. Calcitriol is the biologically active form of which
among the following Vitamins?
(a) Vitamin B
(b) Vitamin C
(c) Vitamin D
(d) Vitamin E
Answer: (c)
Explanation:
Calcitriol is a man-made active form of vitamin D. Most
people get enough vitamin D from exposure to the sun
and from fortified food products (e.g., dairy products,
vitamins). Vitamin D helps control parathyroid hormone
and the levels of certain minerals (e.g., calcium,
phosphorus) that are needed for building and keeping
strong bones.
40. Match the List-I and LIst-II:
| List-I (Organs of the Body) A. Heart B. Kideny C. Eye D. Uterus | List-II (Process of Treatment) 1. Cataract Operation 2. Angioplasty 3. Hysterectomy 4. Dialysis |
Select the correct answer from the codes given below:
A B C D
(a) 1 2 3 4
(b) 2 4 1 3
(c) 4 2 1 3
(d) 1 2 4 3
Answer: (b)
Explanation:
A. Heart Angioplasty
B. Kidney Dialysis
C. Eye Cataract Operation
D. Uterus Hysterectomy
41. Which of the following bacteria forms an
endosymbiotic nitrogen fixing association with roots
of legumes that helps in Nitrogen Fixation?
(a) Clostridium
(b) Rhizobium
(c) Salmonella
(d) Staphylococcus
Answer: (b)
Explanation:
Rhizobium is a bacterium found in soil that helps in
fixing nitrogen in leguminous plants. It attaches to the
roots of the leguminous plant and produces nodules.
These nodules fix atmospheric nitrogen and convert it
into ammonia that can be used by the plant for its
growth and development.
42. Fructose is a form of carbohydrate synthesized in
plants. It becomes table sugar by combining which of
the following?
(a) Glucose
(b) Galactose
(c) Maltose
(d) None of these
Answer: (a)
Explanation:
❖ Fructose, or fruit sugar, is a simple ketonic simple
sugar found in many plants, where it is often bonded
to glucose to form the disaccharide sucrose.
❖ During the process of photosynthesis, cells use
carbon dioxide and energy from the Sun to make
sugar molecules and oxygen. These sugar molecules
are the basis for more complex molecules made by
the photosynthetic cell, such as glucose.
43. The main reason why antibiotics could not solve
all the problems of bacterial diseases is-
(a) Insensitivity of the individual following prolonged
exposure to antibiotics
(b) Inactivation of antibiotics by bacterial enzymes
(c) Decreased efficiency of the immune system
(d) The development of mutant strains resistant to
antibiotics
Answer: (b)
Explanation:
❖ The development of antibiotic-resistant bacteria is
closely related to the extent that antibiotics have
been used in the human body. Due to the prolonged
use of antibiotics, the bacteria become resistant to it
in due course of time. These resistant strains may
grow rapidly or slowly.
44. Which of the following disease is not caused by
viruses?
(a) Cholera
(b) Chickenpox
(c) Hepatitis
(d) Measles
Answer: (a)
Explanation:
❖ Cholera is an acute diarrheal illness caused by
infection of the intestine with Vibrio cholerae
bacteria. People can get sick when they swallow
food or water contaminated with cholera bacteria.
The infection is often mild or without symptoms, but
can sometimes be severe and life-threatening.
45. Which one of the following glands in human body
enlarged due to goiter?
(a) Adrenal cortex
(b) Adrenal medulla
(c) Pituitary
(d) Thyroid
Answer: (d)
Explanation:
❖ A goiter is an abnormal enlargement of your thyroid
gland. A goiter is more often due to the over- or
underproduction of thyroid hormones or to nodules
in the gland itself.
46. Consider the following statements:
1. Carolus Linnaeus is the father of binomial
nomenclature of organisms.
2. The word taxonomy was coined by Augustin de
Candolle.
Which of the above given statements is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (c)
Explanation:
❖ Carl Linnaeus, also known after his ennoblement as
Carl von Linné, was a Swedish botanist, zoologist,
taxonomist, and physician who formalised binomial
nomenclature, the modern system of naming
organisms. He is known as the "father of modern
taxonomy".
❖ De Candolle originated the idea of "Nature's war",
which influenced Charles Darwin and the principle of
natural selection. de Candolle recognized that
multiple species may develop similar characteristics
that did not appear in a common evolutionary
ancestor; a phenomenon now known as convergent
evolution.
47. Consider the following statements:
1. The cell was discovered by Robert Hooke.
2. Nucleus was described by Robert Brown.
Which of the above given statements is/are correct?
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) All statements are correct
Answer: (d)
Explanation:
❖ The cell was first discovered by Robert Hooke in
1665, which can be found to be described in his
book Micrographia.
❖ In 1831, Robert Brown discovered the cell nucleus. -
He is mainly remembered for his descriptions of the
cell nuclei and the continuous motion in the solution
of minute particles called Brownian motion.
48. What fraction of Human Blood is Plasma?
(a) 35%
(b) 45%
(c) 50%
(d) 55%
Answer: (d)
Explanation:
❖ Blood plasma is the liquid component of whole
blood, and makes up approximately 55% of the total
blood volume. It is composed primarily of water with
small amounts of minerals, salts, ions, nutrients, and
proteins in solution. In whole blood, red blood cells,
leukocytes, and platelets are suspended within the
plasma.
49. Ornithophily refers to the pollination through
which among the following?
(a) Wind
(b) Insects
(c) Birds
(d) Water
Answer: (c)
Explanation:
❖ Ornithophily or bird pollination is the pollination of
flowering plants by birds. The plants typically have
colourful, often red, flowers with long tubular
structures holding ample nectar and orientations of
the stamen and stigma that ensure contact with the
pollinator.
50. Which among the following is not among Micronutrients required for plants?
(a) Molybdenum
(b) Magnesium
(c) Manganese
(d) Zinc
Correct answer B