Olympiad Test Level 1: Science and Technology - 1 - Class 4 MCQ

Simple machines are basic mechanical devices that make work easier. A screwdriver is an example of a simple machine, specifically a lever. It helps in turning screws and accomplishing tasks with less effort.

The primary function of the lungs is to facilitate the exchange of gases, particularly oxygen and carbon dioxide, during the process of breathing. This exchange is crucial for providing oxygen to the body's cells and removing carbon dioxide, a waste product.

Mars is often referred to as the "Red Planet" due to its reddish appearance, caused by iron oxide (rust) on its surface. It is the fourth planet from the Sun in our solar system.

Photosynthesis is the process by which plants use sunlight, carbon dioxide, and water to produce glucose (a form of sugar) and oxygen. This vital process is the foundation of the food chain.

Solar power is derived from the sun and is considered a renewable source of energy. It harnesses sunlight to generate electricity and is environmentally friendly compared to non-renewable sources like coal and natural gas.

The Blue Whale holds the title of the largest mammal on Earth. These magnificent creatures can reach lengths of up to 100 feet and weigh as much as 200 tons.

Copper is an excellent conductor of electricity. It is commonly used in electrical wiring and circuits due to its ability to allow the flow of electric current.

Gravitational force, the attraction between objects with mass, is responsible for keeping planets in orbit around the Sun. It is the same force that keeps us grounded on Earth.

The Earth's atmosphere serves multiple purposes, including reflecting sunlight, holding in heat, and providing the essential gases, including oxygen, for life on Earth.

The kidneys play a crucial role in filtering waste and excess fluids from the blood to form urine. This process helps maintain a balance of electrolytes and fluids in the body.