Astronomers observed that the orbit of Uranus was not uniform. Therefore, they hypothesized the existence of another planet. This is an example of scientific investigation being led by

Which of the following are guidelines to follow for obtaining accurate observations

Acoil suspended freely, points in some direction when no current is passed through it . can you tell what will happen when a current is passed though it?

The illuminance of a surface varies inversely with the square of its distance from the light source. if the illuminance of a surface is 120 lumens per square meter when its distance from a certain light source is 6 meters, by how many meters should the distance of the surface from the source be increased to reduce its illuminance to 30 lumens per square meter?