knockingpoint

Heat energy is generated when current flows through a conductor. The heating effect of an electric current depends on below-given factors: The resistance, R of the conductor= A higher resistance produces more heat. The time, t for which current flows= The longer the time the larger the amount of heat produced The amount of current, I= Higher the current, larger the amount of heat generated. Joule’s Equation of Electrical Heating Hence the heating effect produced by an electric current, I through a conductor of resistance, R for a time, t is given by  H = I 2 Rt.  This equation is called the Joule’s equation of electrical heating. Electrical energy and power The work done in pushing a charge around an electrical circuit is given by Work= VIt So that power,  P = Work /t = VI The electrical power consumed by an electrical appliance is given by  P = VI = I 2 R = V 2 /R Numerical An electrical bulb has 100W & ...

Sound is a form of energy which stimulates our sense of hearing. Everyday, we hear many sounds all around us all the time: the radio blaring, the telephone bell ringing, students, friends’ talking to each other and so on. How is sound produced? If we touch a silent bicycle bell we do not find anything special in it. If we ring the bell and touch it gently, we’ll find that the bell is vibrating continuously till such time that it stops ringing. As it is ringing if we hold it tightly, the vibrations will stop and no sound will be heard. This clearly tells us that sound is produced by vibrating bodies. The vibrating body has a certain amount of energy which travels in the form of sound waves. This energy is provided to it by some outside source. Sound can be produced by the following methods:  (i) by vibrating strings as in veena, violin, etc., known as string instruments. (ii) by vibrating air as in flute, trumpets, etc., known as wind instruments. (iii) by vibrating membranes as...

All about sound All about sound.!!! 1.Sound travels from one point to another in the form of waves. 2. Sound is produced due to vibration of different objects. 3. Sound waves are longitudinal in nature. 4. Sound travels as a longitudinal wave through a material medium. 5. Sound travels as successive compressions and rarefactions in the medium. 6. In sound propagation, it is the energy of the sound that travels and not the particles of the medium. 7. Sound cannot travel in vacuum. 8. Sound waves cannot be polarised. 9. The change in density from one maximum value to the minimum value and again to the maximum value makes one complete oscillation. 10. The part or region of a longitudinal wave in which the density of the particles of the medium is higher than the normal density is known as compression. 11. The part or region of a longitudinal wave in which the density of the particles of the medium is lesser than the normal density is called a rarefaction. 12. The distance ...

Light is a electromagnetic waves that is also transverse wave. Light is form o energy has wavelength between 3900 A° to 7800A°. Photoelectric effect, Compton Effect will be explained by using on the basis of the theory as proposed by Einstein . Its speed measure by Romer (1678 AD).  . 🎻 Refractive index:  it is a medium which is defined using the ratio of light in vacuum to the speed of light in medium. Refractive Index varies in various medium. In small refractive index velocity of light is large.Sun light takes 8 minutes to reach to earth. . 🎻 Reflection of Light: One way to change the direction of light is to let it fall on a shiny surface.For example, a shining stainless steel plate or a shining steel spoon can change the direction of light.The distance between mirror to object and mirror to image is equal distance.Water surface is a medium of change light and its act like a mirror.When light falls in mirror its chan...