ELECTRICITY Electricity time ‘t’, then the current flowing through the conductor is I = ( . ) . . SI unit of electric current The SI unit of electric current is ampere (A).
The current flowing through a conductor is said to be one ampere, when a charge of one coulomb flows across any cross-section of a conductor, in one second. Hence, ampere = . Solved Problem- A charge of coulomb flows through a bulb in second. What is the current through the bulb?
Solution: Charge Q = C, Time t = s. Therefore, current I = = = . A . ELECTRIC CIRCUIT An electric circuit is a closed conducting loop (or) path, which has a network of electrical components through which electrons are able to flow.
This path is made using electrical wires so as to connect an electric appliance to a source of electric charges (battery). A schematic diagram of an electric circuit comprising of a battery, an electric bulb, and a switch is given in Figure . . Figure .
A simple electric circuit Table . Symbols of some components of a circuit COMPONENT USE OF THE COMPONENT SYMBOL USED Resistor Used to fix the magnitude of the current through a circuit Variable resistor or Rheostat Used to select the magnitude of the current through a circuit. Ammeter Used to measure the current. Voltmeter Used to measure the potential difference.
Galvanometer Used to detect the current and its direction. A diode It is used in electronic devices. Light Emitting Diode (LED) It is used in seven segment display. Ground connection Used to provide protection to the electrical components.
It also serves as a reference point to measure the electric potential. th Standard Science In this circuit, if the switch is ‘on’, the bulb glows. If it is switched off, the bulb does not glow. Therefore, the circuit must be closed in order that the current passes through it.
The potential difference required for the flow of charges is provided by the battery.