DEFINITION AND CONCEPT Electromagnetic waves are produced by electromagnetic vibrations. Electromagnetic waves have electrical origin and the ability to travel in vacuum. So, electromagnetic waves are regarded as a combination… Read More »ELECTROMAGNETIC WAVES
Conductors, insulators and semi-conductors i) An insulatoris a material or object which resists flow of heat (thermal insulator) or electrical charges (electrical insulators). Examples are paraffin, wood, rubber, plastics etc.… Read More »ELECTRONICS
Introduction Radioactivity was discovered by Henri Becquerel in 1869. In 1898, Marie and Pierre Curie succeeded in chemically isolating two radioactive elements, Polonium (z=84) and Radium (z= 88). Radioactivity or… Read More »RADIOACTIVITY
Photoelectric effect was discovered by Heinrich Hertz in 1887. Photoelectric effect is a phenomenon in which electrons are emitted from the surface of a substance when certain electromagnetic radiation falls… Read More »PHOTOELECTRIC EFFECT
Electromagnetism is the effect resulting from the interaction between an electric current and a magnetic field. This effect brings about induced electromagnetic force (e.m.f) and the resulting current is called… Read More »ELECTROMAGNETIC INDUCTION
What is Electromagnetic?. Electromagnetic spectrum is a continuum of all electromagnetic waves arranged according to frequency and wavelength. It includes visible light, ultra-violet rays, microwaves, X-rays, radio waves and gamma… Read More »ELECTROMAGNETIC SPECTRUM
Introduction Circular motion is the motion of bodies travelling in circular paths. Uniform circular motion occurs when the speed of a body moving in a circular path is constant. This… Read More »UNIFORM CIRCULAR MOTION
Any object in a liquid whether floating or submerged experiences an upward force from the liquid; the force is known as upthrust force. Upthrust force is also known as buoyant… Read More »FLOATING AND SINKING
Pressure law This law states that “the pressure of a fixed mass of a gas is directly proportional to the absolute temperature if the volume is kept constant”. The comparison… Read More »THE GAS LAWS
What is heat?. Heat is a form of energy that flows from one body to another due to temperature differences between them. Heat capacity Heat capacity is defined as the… Read More »QUANTITY OF HEAT
When current flows, electrical energy is transformed into other forms of energy i.e. light, mechanical and chemical changes. Factors affecting electrical heating Energy dissipated by current or work done as… Read More »HEATING EFFECT OF AN ELECTRIC CURRENT
Electric fields An electric field is the space around a charged body where another charged body would be acted on by a force. These fields are represented by lines of… Read More »ELECTROSTATICS
Electric potential difference and electric current Electric current: Electric potential difference (p. d) is defined as the work done per unit charge in moving charge from one point to another.… Read More »CURRENT ELECTRICITY
Newton’s first law (law of inertia) This law states that “A body continues in its state of rest or uniform motion unless an unbalanced force acts on it”. The mass… Read More »NEWTON LAWS OF MOTION
Introduction Refraction is the change of direction of light rays as they pass at an angle from one medium to another of different optical densities. Exp. To investigate the path… Read More »REFRACTION OF LIGHT
Fluid in physics refers to liquids and gases. To study fluid flow we have to make the following assumptions: We consider fluids to be incompressible We assume that they have… Read More »FLUID FLOW
Introduction: Oersted’s discovery. Hans Christian Oersted discovered the magnetic effect of a current in 1819. The direction of the field is dependent on the direction of the current. This discovery… Read More »MAGNETIC EFFECT OF AN ELECTRIC CURRENT
Measuring length using vernier callipers. Vernier callipers is used when higher accuracy in measurement is required and this cannot be done using a metre rule. Vernier callipers has two scales;… Read More »MEASUREMENT II
Work done per unit charge is called electrical potential. Current is the flow of charge. For current to be continuous, potential difference between the two points must be sustained. Sources… Read More »CELLS AND SIMPLE CIRCUITS
Some substances get charged when rubbed against other substances i.e. nylon, plastic, paper etc. the charge acquired stays within the body i.e. it does not move and therefore known as… Read More »ELECROSTATICS I