Q: Sodium stearate is a salt and is used?

A: in gunpowder

B: in Paint

C: to make Soap

D: to make fertilizer



Correct Option: C  [ to make Soap ]

Remark:


Q: The weight of a body at the centre of the earth is:

A: zero

B: infinite

C: same as at other places

D: none of these



Correct Option: A  [ zero ]

Remark:

Explanation: The weight of a body at the centre of the Earth is zero because the gravitational forces from all directions cancel each other out. Although the body still has mass, it experiences no gravitational pull, resulting in zero weight.


Q: Liquid natural gas (LNG) predominantly contains _______ in liquid form.

A: Ethane

B: Ethylene

C: Methane

D: Methylene



Correct Option: C  [ Methane ]

Remark:

Explanation: Liquid Natural Gas (LNG) predominantly contains methane (CH₄) in liquid form. It is produced by cooling natural gas to about −162°C, which reduces its volume for easier storage and transportation. LNG is a clean fuel with high energy efficiency and low emissions.


Q: Normal human blood is:

A: Acidic

B: Alkaline

C: Neutral

D: Variable



Correct Option: B  [ Alkaline ]

Remark:

Explanation: Normal human blood has a slightly alkaline pH of 7.35 to 7.45. This pH is maintained by buffer systems such as the bicarbonate buffer system and controlled by the lungs (CO₂ regulation) and kidneys (acid-base balance). A deviation from this range can be life-threatening — acidosis occurs if pH falls below 7.35, and alkalosis occurs if it rises above 7.45.


Q: Which one of the following gases, present in the air near the surface of the Earth, has maximum concentrations?

A: Oxygen

B: Hydrogen

C: Nitrogen

D: Methane



Correct Option: C  [ Nitrogen ]

Remark:


Q: A transformer is used to :

A: Increase or decrease D.C voltage

B: Increase or decrease A.C voltage

C: Convert A.C to D.C

D: Convert D.C into A.C



Correct Option: B  [ Increase or decrease A.C voltage ]

Remark:

Explanation: A transformer is an electrical device used to increase (step-up) or decrease (step-down) the voltage of alternating current (A.C.). It works on the principle of electromagnetic induction and functions only with A.C., not with D.C. A transformer consists of two coils—primary and secondary—wound around a soft iron core. The voltage ratio between these coils depends on the number of turns in each winding. Transformers are used in power transmission, distribution, and electronic devices to regulate voltage levels efficiently.


Q: The amount of light entering into eye can be controlled and regulated by ___________ .

A: Sclera

B: cornea

C: pupil

D: retina



Correct Option: C  [ pupil ]

Remark:

Explanation: The pupil is the central opening in the iris that regulates the entry of light into the eye. In bright light, the iris contracts, making the pupil smaller (a process called constriction), while in dim light, it enlarges (known as dilation). This automatic adjustment, known as the pupillary reflex, helps protect the retina from excessive light and ensures clear vision in varying light condit


Q: Intestinal bacteria synthesizes which vitamin in the human body?

A: Vitamin A

B: Vitamin C

C: Vitamin D

D: Vitamin K



Correct Option: D  [ Vitamin K ]

Remark:

Explanation: Vitamin K is produced by gut bacteria (Escherichia coli) in the large intestine. It plays a vital role in the synthesis of prothrombin, a protein essential for normal blood clotting. Although some of it is obtained from food (like leafy vegetables), intestinal bacteria supply a significant portion of the body’s requirement.


Q: Seismology is the science of :

A: Atmosphere

B: Earthquake

C: Fossil

D: Silkworm breeding



Correct Option: B  [ Earthquake ]

Remark:

Explanation: Seismology is the branch of geophysics that deals with the study of earthquakes and the propagation of seismic waves through the Earth. Scientists who study earthquakes are called seismologists. Seismology helps in understanding the origin, intensity, and effects of earthquakes, as well as the internal structure of the Earth. The intensity of an earthquake is measured using instruments like the seismograph and scales such as the Richter scale or Moment Magnitude scale.


Q: Which of the following is the structural and functional unit of kidneys?

A: Nephron

B: Pits

C: Nutrofil

D: Tentacle



Correct Option: A  [ Nephron ]

Remark:

Explanation: The nephron is the basic structural and functional unit of the kidney. Each human kidney contains about 1 to 1.5 million nephrons. A nephron consists of two main parts — the renal corpuscle (Bowman's capsule and glomerulus) and the renal tubule. It performs three main functions: filtration of blood, reabsorption of essential substances, and secretion

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