Spring tides occur during New and Full Moons when the gravitational pulls of the Sun and Moon are aligned, creating the greatest difference between high and low tide.

Venus is the hottest planet in the Solar System. Its thick CO2 atmosphere creates a runaway greenhouse effect, trapping heat and raising surface temperatures to around 465°C.

In astronomy, the color of a star indicates its surface temperature. Blue and blue-white stars are the hottest, with temperatures exceeding 30,000 Kelvin, while red stars are the coolest.

Haematology studies blood, blood-forming organs, and related diseases such as anemia and leukemia. It includes diagnostics like blood counts and coagulation tests. Pathology more broadly addresses disease mechanisms, dermatology covers skin, and “Entramology” is not a recognized specialty. Therefore, haematology is correct.

Graphology claims to analyze personality through handwriting features such as slant and pressure. While scientifically contested, the term clearly refers to handwriting. Shell composition is conchology, geomagnetism concerns Earth’s field, and psephology studies elections. Therefore, A is correct.

Theories are developed after extensive testing and verification. They explain natural phenomena and predict outcomes. Unlike guesses, theories are supported by strong evidence.

The independent variable is manipulated to test its effect on the dependent variable. Controlled variables remain unchanged to ensure fairness. This distinction helps identify cause-and-effect relationships.

A controlled experiment isolates a single independent variable to determine its effect. All other factors are kept constant. This ensures reliable results and reduces confusion caused by multiple influences.

A hypothesis is a tentative statement predicting what might happen in an experiment. It is testable and forms the basis for investigation. If supported by evidence, it can lead to theories or laws.

In science, a theory is a comprehensive explanation supported by significant evidence. It explains patterns and predicts outcomes. Unlike a hypothesis, which is a testable guess, a theory has been repeatedly validated.