Anaemia is caused due to a deficiency of iron in the body. Iron is an essential component of hemoglobin, the protein in red blood cells that carries oxygen. When the body lacks sufficient iron, it produces fewer and smaller red blood cells, leading to symptoms such as fatigue, weakness, dizziness, and pale skin. This condition is known as Iron-Deficiency Anaemia.

Other options (for context)

• Iodine: Its deficiency causes goitre, not anaemia.
• Vitamin: Certain vitamins like B₁₂ and folic acid deficiency can cause anaemia, but the most common cause is lack of iron.
• None of these: Incorrect — iron deficiency is the main cause of anaemia.

Explanation: The rusting of iron is an example of oxidation. When iron reacts with oxygen and moisture from the air, it forms hydrated ferric oxide (Fe₂O₃·xH₂O), commonly known as rust. This process involves the loss of electrons by iron, which is a characteristic feature of oxidation.

The CPU (Central Processing Unit) is known as the brain of the computer. It performs all major operations such as processing data, executing instructions, and controlling other components. The CPU consists of two main parts — the Arithmetic Logic Unit (ALU) for calculations and the Control Unit (CU) for directing operations.

• ALU: Handles arithmetic and logic operations only.
• Memory: Stores data and instructions, but doesn’t process them.
• Control Unit: Directs the flow of data but works as part of the CPU.

Explanation: The full form of USB is Universal Serial Bus. It is a standard interface used to connect devices such as keyboards, mice, flash drives, and printers to a computer. USB allows data transfer and power supply between connected devices.

Explanation: The Growth Hormone (GH), also known as Somatotropin, is secreted by the anterior lobe of the pituitary gland, which is located at the base of the brain. This hormone stimulates growth, cell reproduction, and regeneration in humans and other animals. It plays a vital role in increasing height during childhood and adolescence, regulating metabolism, and maintaining muscle and bone mass. A deficiency of GH causes dwarfism in children, while excess secretion leads to gigantism or acromegaly.

Explanation: Execution time is the period during which a job or program is actively processed by the computer’s CPU. It refers to the actual time taken to execute instructions, excluding waiting or idle times such as input/output delays or queue time.

Explanation: Smallpox is a highly contagious and deadly disease caused by the Variola virus. It is characterized by high fever, fatigue, and a distinctive pustular rash on the skin. Smallpox was one of the most devastating diseases in human history, but thanks to the worldwide vaccination campaign led by the World Health Organization (WHO), it was officially eradicated in 1980. The vaccine for smallpox was first developed by Edward Jenner in 1796.