SOE / MERITORIOUS ANSWER KEY CLASS 11 ( SCIENCE )

Science Questions (Answered)

61. Methane gas released from waste treatment plants can be used as a source of fuel. Which chemical equation represents combustion of methane to produce heat energy?

1. CH₄ + CO₂ → 2O₂ + 2H₂O
2. CH₄ + 2O₂ → CO₂ + 2H₂O
3. 2O₂ + 2H₂O → CO₂ + CH₄
4. CO₂ + 2O₂ → CH₄ + 2H₂O

Correct Answer: (2) CH₄ + 2O₂ → CO₂ + 2H₂O

62. Surjit was advised by her teacher to wear gloves and use forceps while dipping the pH paper in the liquid. What was the reason for this advice?

1. Gloves keep the hands warm
2. Forceps look beautiful
3. Gloves protect hands from corrosive liquids
4. No need to use while handling liquids

Correct Answer: (3) Gloves protect hands from corrosive liquids

63. How many atoms of sulphur will react with one atom of magnesium to form a compound?

1. One
2. Two
3. Three
4. Four

Correct Answer: (1) One (Mg + S → MgS)

64. Acid + Metal → Salt + X. What is X in the equation?

1. Hydrogen
2. Carbon dioxide
3. Water
4. Nitrogen

Correct Answer: (1) Hydrogen (General reaction: Acid + Metal → Salt + H₂)

65. Which of these is another way of representing the bonds between the atoms of a nitrogen molecule?

1. N ≡ N
2. N ≢ N
3. N ≡ N
4. N - N

Correct Answer: (3) N ≡ N (Nitrogen molecule has a triple bond)

66. Which of these health conditions is caused by hormonal imbalance in the body?

1. Scurvy
2. Typhoid
3. Diabetes
4. Common Cold

Correct Answer: (3) Diabetes

67. Which of the following diseases is caused by a sexually transmissible bacterium?

1. Wart
2. Cholera
3. Influenza
4. Gonorrhoea

Correct Answer: (4) Gonorrhoea

68. What type of image is formed on the retina?

1. Virtual and Inverted
2. Real and Inverted
3. Virtual and Erect
4. Real and Erect

Correct Answer: (2) Real and Inverted

69. The table shows four different materials and their resistivity. Which material is the best conductor of electricity?

• Material 1: 1.62 × 10⁻⁸ Ωm
• Material 2: 100 × 10⁻⁸ Ωm
• Material 3: 6.84 × 10⁻⁸ Ωm
• Material 4: 44 × 10⁻⁶ Ωm

1. Material 1
2. Material 2
3. Material 3
4. Material 4

Correct Answer: (1) Material 1 (Lowest resistivity = best conductor)

70. What does the symbol —/\/\/\— mean in an electric circuit?

1. Switch
2. Wire joint
3. Electric bulb
4. Variable resistance

Correct Answer: (4) Variable resistance

71. Three resistors are connected in parallel combination in the circuit as shown. What is the equivalent resistance of the circuit?

1. Less than 1 Ω
2. 1 Ω
3. 2 Ω
4. More than 2 Ω

Correct Answer: statement wrong 

72. Which of these devices works due to the magnetic effect of electric current?

1. LED Bulb
2. Electric Bell
3. Electric Heater
4. Mobile Charger

Correct Answer: (2) Electric Bell

73. The ozone layer shields the Earth's surface from UV radiation of the sun. Which of these is likely to increase in humans with the depletion of the ozone layer?

1. AIDS
2. COVID
3. JAUNDICE
4. SKIN CANCER

Correct Answer: (4) SKIN CANCER

74. Surjit digs a pit in his garden and puts the following items in it. Which will decompose?

1. Paper Cups
2. Rubber Slippers
3. Glass Bowls
4. Metal Clip

Correct Answer: (1) Paper Cups

75. The breakdown of pyruvate to give carbon dioxide, water, and energy takes place in:

1. Cytoplasm
2. Mitochondria
3. Chloroplast
4. Nucleus

Correct Answer: (2) Mitochondria

76. Gurjeet is not able to see clearly the blackboard when she sits on the back bench of the class but can see her book clearly. She is suffering from:

1. Short sightedness
2. Long sightedness
3. Cataract
4. None

Correct Answer: (1) Short sightedness

77. The gap between two neurons is called:

1. Dendrite
2. Synapse
3. Axon
4. Impulse

Correct Answer: (2) Synapse

78. When you have a problem of indigestion, you visit a doctor. The doctor will give you:

1. Antibiotic
2. Analgesic
3. Antacid
4. Antiseptic

Correct Answer: (3) Antacid

79. Ranjit is suffering from hypermetropia. Doctor advised him convex lens. Suppose power of convex lens is 2 Dioptre, what will be its focal length?

1. 20 cm
2. 40 cm
3. 10 cm
4. 50 cm

Correct Answer: (4) 50 cm
Explanation: Focal length (in meters) = 1 / Power = 1 / 2 = 0.5 m = 50 cm

80. What would happen if north pole of a magnet comes closer to the north pole of another magnet?

1. Attract each other
2. Repel each other
3. Electromagnet
4. Solenoid

Correct Answer: (2) Repel each other

81. One day Anju was stung by a honey-bee. Bee sting leaves an acid which causes pain and irritation. Her teacher applied some chemical. What was that chemical?

1. Baking Soda
2. Milk of Magnesia
3. Calcium Phosphate
4. Lemon Juice

Correct Answer: (1) Baking Soda

82. Gold is used for making jewellery. They are of variable type. One of them is very soft. Identify it.

1. 22 carat
2. 18 carat
3. 24 carat
4. 14 carat

Correct Answer: (3) 24 carat

83. Among the following which one is sweet-smelling substance used for making perfumes and as flavoring agent?

1. Ester
2. Acetone
3. Vinegar
4. Formic Acid

Correct Answer: (1) Ester

84. Which hormone is responsible for dramatic changes in male as they approach the age of 10-12 years?

1. Oestrogen
2. Testosterone
3. Insulin
4. Adrenaline

Correct Answer: (2) Testosterone

85. One day Sukhman observed buds in the notches along the leaf margin. She saw when these buds fall on the soil, they develop into new plants. Name that plant:

1. Bryophyllum
2. Spirogyra
3. Hydra
4. Planaria

Correct Answer: (1) Bryophyllum

86. An electric iron which consumes 1 kW electric power at 220 V, a current of 4.54 A will flow in the circuit. In this case which type of fuse is used?

1. 1 A
2. 2 A
3. 3 A
4. 5 A

Correct Answer: (4) 5 A

87. An electron enters a magnetic field at right angles to it as shown in fig.
The direction of force acting on the electron will be:

1. To the right
2. To the left
3. Out of the page
4. Into the page

Correct Answer: (4) Into the page

88. Biotic component in an ecosystem comprises of:

1. Temperature
2. Wind
3. Living Organism
4. Soil

Correct Answer: (3) Living Organism

89. Speed of light in vacuum is:

1. 6 × 10⁸ m/s
2. 3 × 10⁸ m/s
3. 6 × 10¹⁰ m/s
4. 3 × 10¹⁰ m/s

Correct Answer: (2) 3 × 10⁸ m/s

90. Whose chromosomes are responsible for determining the sex of a child in human beings?

1. Female
2. Male
3. Both
4. None

Correct Answer: (2) Male