Measurement is the process of comparison of the given physical quantity with the known standard quantity of the same nature. A unit is the quantity of a constant magnitude that is used to measure the magnitudes of other quantities of the same nature. The magnitude of a physical quantity is expressed as Physical quantity = […]

Newton’s first law: If a body is in a state of rest, then it will remain in that state, and if the body is in a state of motion, then it will continue moving with the same velocity in the same direction unless an external force is applied on it. The property of an object

The magnets found in nature are called natural magnets. An artificial magnet is a magnetized piece of iron or any other magnetic material. Some forms of artificial magnets are bar magnets, horseshoe magnets, magnetic needles, magnetic compasses, etc. If a magnet is suspended with a silk thread such that it is free to rotate in

The weight of the object exerts a force on the liquid. The liquid also exerts a certain amount of force on the object in the upward direction. This force is called the buoyant force. The tendency of a liquid to exert an upward force on any object immersed in it is called buoyancy. The upward

The regular pencil cells used in daily life provide a direct current. Direct current is a current of constant magnitude flowing in one direction. Electric Current is a scalar quantity. Its SI unit is ampere (A). Conventionally, the direction of current is taken in the direction of the flow of positive charge. This direction is

A body is said to be at rest if its position with respect to its surrounding does not change. While a body is said to be in motion if its position changes with respect to its surroundings. One-dimensional motion: When a body moves along a straight line path, its motion is said to be a

The return of light into the same medium after striking a surface is called reflection. We see the objects around us due to reflection. A plane mirror reflects almost all the light falling on it. When a beam of light falls on a smooth and polished surface (a plane mirror), regular reflection occurs. When a

A lens is a transparent refracting medium bounded by two curved surfaces, of which one or both surfaces are spherical. A lens with both surfaces bulging outwards is called a double convex lens or simply a convex lens. A convex lens converges the light rays incident on it to a point. Hence, a convex lens

Sound is produced and is heard when a body vibrates in a medium. When the vibrations reach our ears, a sound is heard. Our ears are sensitive only to a limited range of frequencies, from 20 Hz to 20,000 Hz. Sound of frequency above 20,000 Hz is called ultrasonic, while the sound of frequency below

Machines help us to perform daily activities in a better efficient way. A machine can be defined as a device by which we can either overcome a large resistive force (or load) at some point by applying a small force (or effort) at a convenient point and in a desired direction or by which we