Q: Which of the following adds/add carbon dioxide to the carbon cycle on the planet earth ?
1. Volcanic action
2. Respiration
3. Photosynthesis
4. Decay of organic matter
(Select correct answer)


A: 1, 2 and 4 only

B: 1 and 3 only

C: 2 only

D: 1, 2 and 3 only



Correct Option: A  [ 1, 2 and 4 only ]

Remark:

Explanation: The processes that add carbon dioxide (CO₂) to the carbon cycle on Earth are:

  • 1. Volcanic action: Volcanic eruptions release large amounts of CO₂ and other gases from the Earth’s interior into the atmosphere.
  • 2. Respiration: All living organisms release CO₂ as a by-product of breaking down glucose during cellular respiration.
  • 4. Decay of organic matter: Decomposition of dead plants and animals by microbes produces CO₂ and methane (CH₄).

Photosynthesis (option 3), on the other hand, removes CO₂ from the atmosphere as plants use it to produce glucose and release oxygen.


Q: The number of milk teeth in man is

A: 28

B: 29

C: 20

D: 12



Correct Option: C  [ 20 ]

Remark:

Explanation: Humans first develop a set of 20 milk teeth (also called deciduous or primary teeth) — 10 in the upper jaw and 10 in the lower jaw. These teeth start erupting around 6 months of age and are eventually replaced by 32 permanent teeth (including 4 wisdom teeth). Milk teeth help in early chewing, speaking, and maintaining space for permanent teeth.


Q: When a sound wave goes from one medium to another, the quantity that remains unchanged is:

A: Frequency

B: Amplitude

C: Wavelength

D: Speed



Correct Option: A  [ Frequency ]

Remark:

Explanation: When a sound wave travels from one medium to another, its frequency remains unchanged. However, its wavelength and speed change depending on the properties of the new medium. The constant frequency ensures that the sound maintains the same pitch.


Q: ELISA stands for:

A: Enzyme-linked immunosorbent assay

B: Epithelium lesions in surface analysis

C: Energy-linked immunity assay

D: Enzyme-linked immunity analysis



Correct Option: A  [ Enzyme-linked immunosorbent assay ]

Remark:

Explanation: ELISA stands for Enzyme-linked immunosorbent assay. It is a biochemical test used to detect and measure antibodies, antigens, proteins, or hormones in a sample. The method relies on an enzyme-linked antigen or antibody and a color change to indicate a positive reaction.


Q: Magnetic effect of current gives rise to which force ?

A: mechanical

B: frictional

C: spring

D: gravitational



Correct Option: A  [ mechanical ]

Remark:

The magnetic effect of current gives rise to a mechanical force. When an electric current passes through a conductor placed in a magnetic field, it experiences a force that can cause motion — this is known as the motor effect. This principle is used in devices like electric motors, galvanometers, and loudspeakers.

  • Frictional force: Arises due to contact between surfaces.
  • Spring force: Related to elasticity.
  • Gravitational force: Due to attraction between masses, unrelated to current.


Q: The SI unit of temperature is

A: Temperature

B: Ampere

C: Watt

D: Kelvin



Correct Option: D  [ Kelvin ]

Remark:


Q: The Bhopal Gas Tragedy was caused by :

A: Phosgen gas

B: Carbon monoxide

C: Methyl isocyanate

D: Chlorine



Correct Option: C  [ Methyl isocyanate ]

Remark:

Explanation: The Bhopal Gas Tragedy occurred on the night of December 2–3, 1984, at the Union Carbide pesticide plant in Bhopal, Madhya Pradesh (India). The disaster was caused by the accidental leakage of Methyl Isocyanate (MIC), a highly toxic and reactive gas used in pesticide manufacturing. The poisonous gas spread rapidly over the nearby populated areas, killing thousands of people and causing severe respiratory and neurological disorders. It is considered one of the world’s worst industrial disasters.


Q: The intensity of earthquake is measured by :

A: Barometer

B: Hydrometer

C: Polygraph

D: Seismograph



Correct Option: D  [ Seismograph ]

Remark:

Explanation: The intensity and magnitude of an earthquake are measured using a scientific instrument called a seismograph. It records the vibrations or seismic waves produced by earthquakes. The data obtained from a seismograph are used to calculate the earthquake’s strength on scales such as the Richter Scale or the Moment Magnitude Scale. The seismogram (the recorded graph) shows the amplitude and duration of the waves, helping scientists locate the earthquake’s epicenter and determine its severity.


Q: Opium is derived from which part of poppy plant ?

A: Seeds

B: Leaves

C: Bark

D: Capsule



Correct Option: D  [ Capsule ]

Remark:

Explanation: Opium is obtained from the latex present in the unripe capsule of the poppy plant (Papaver somniferum). The latex is collected by making incisions on the capsule, and after drying, it forms raw opium, which contains alkaloids like morphine and codeine.


Q: In which part of the human body carpal bones are found ?

A: Wrist

B: Femur

C: Neck

D: None of these



Correct Option: A  [ Wrist ]

Remark:

Explanation: Carpal bones are the eight small bones that make up the wrist (also known as the carpus) in the human skeletal system. These bones are arranged in two rows — a proximal row (closer to the forearm) and a distal row (closer to the hand). They connect the bones of the forearm (radius and ulna) to the bones of the hand (metacarpals) and allow for the flexibility and movement of the wrist. The carpals are essential for various hand motions like bending, rotation, and gripping.

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