An essential energy source is electricity. One of the effects of electricity is the foundation for all electrical gadgets. For instance, chemical, thermal, magnetic, etc. effects. This chapter enlightens us on the various effects of electricity.
$I^{2}RT$
$H=\left(\frac{V}{R} \right)^{2} * RT = \frac{V^{2}RT}{R^{2}}$
Ø Effects of electricity: Heating effect, lighting effect, chemical effect, mechanical effect and magnetic effect.
Ø Heating effect of electric current - The essential component of a heat-producing device is the heating coil. The alloy of nickel, chromium, iron, and manganese known_as nichrome is used to make heating coils.
Ø Advantages of Nichrome - The benefits of nichrome include its high resistivity, high_melting point, and long-lasting red-hot condition without oxidation.
Ø The factors that affect the amount of heat developed in a conductor are intensity_of electric current (I), resistance of the conductor (R), time of flow of current (t).
Ø Joules law : The heat generated in a current carryinq conductor is the product of the_square of the current (I) in the conductor, the resistance of the conductor (R) and the time (t) of flow of current.
Ø If we substitute the value of for $\frac{V}{R}$
I in H = $I^{2}RT$
$H=\left(\frac{V}{R} \right)^{2} * Rt = \frac{V^{2}Rt}{R^{2}}$
Ø Similarly replace R with
$\frac{V}{I} \ in \ H = I^{2}Rt$
$H = I^{2}Rt$
$H = I^{2}-\frac{V}{I}t = VIt$
$H=VIt=I^{2}Rt= \frac{V^{2}t}{R}$
Ø When resistors are connected in series the effective resistance
R = R1 + R2 + R3
Ø When resistors are connected in parallel the effective resistance.
$\frac{1}{R} = \frac{1}{R_{1}} + \frac{1}{R_{2}} + \frac{1}{R_{3}}$
A safety fuse uses the heating effect of electric current to operate. It is a tin and lead alloy. A fuse wire's melting point is low.
Ø Safety Fuse - A safety fuse uses the heating effect of electric current to operate. It is a tin and lead alloy. A fuse wire's melting point is low.
Ø Electric circuits are shielded by fuse wires from short-circuit or overload damage.
Ø Short circuit - A short circuit is created when the positive and negative terminals of a battery or the two mains cables come into touch without a resistance in between.
Ø When all of the appliances connected to a circuit have more power than the circuit can handle, the circuit is said to be overloaded.
Ø Amperage is the product of an equipment's power and the applied voltage. Amperage rises as conductor thickness increases
Ø Lighting Effect of Electric Current.
Incandescent lamp :
Ø Discharge lamp - Electrodes and a glass tube filled with a gas at low pressure make up the discharge lamp's essential components. The applied potential difference ionises the gas between the electrodes in a discharge lamp when it is coupled to an electrical source. High-speed collisions between ionised and unionised atoms occur.
Ø During this process the energy stored in them will be radiant as light. The gas inside the discharge lamp determines the colour of the light.
Ø Fluorescent lamp contains heating coil coated with thorium oxide, glass tube coated with fluorescent substance, Hg vapour etc. Unionized mercury vapour molcules are struck by the quickly travelling electrons. Ultraviolet rays are consequently created. The fluorescent substance absorbs these photons, which are then reemitted as visible light.Some fluorescent bulbs also emit blue light and ultraviolet radiation. In addition to being employed in banks to identify false currency and documents, they are fly traps.
Ø Compact fluorescent lamps (CFL) : created to operate at low power. CFLs operate in a manner akin to that of fluorescent lamps.
Ø Light Emitting Diode: These lights produce more light while using less electricity. Advantages of LED lamps: No filament and no loss of energy since there is no mercury in It, It is not harmful to environment.
Ø Arc lamp - The primary component of this lamp is a set of carbon rods held at a predetermined distance inside of an evacuated glass tube..
Ø When a high voltage is introduced between them, an electric discharge occurs, producing intense light for the arc lamp.
Ø Electric power : An electrical appliance's power is defined as how much electricity it uses in a certain period of time.
$P = \frac{H}{T} \ = \ IR^{2} \ = \ IV = \frac{V^{2}}{R}$
Unit of power is watt (W)
Ø Building of LED bulbs. Punching the base unit onto the heat sink will fix it. Insulation tapes should be used to wrap the power supply board so that the input and output supply wires are visible but not obstructed by dust or moisture. Passing the wires through the heat sink and terminal holes will secure the wires visible on the input portion of the power supply board to the rear conductor. Fix the red wire in the output into the part marked positive in the board and the black wire into the negative marking. Apply heat sink compound at the back of the LED Printed Circuit Board and then fix it on the base plate. Press and close the heat sink by using the diffuser cup.
Ø Tools required to repair LED bulbs
· Solderinq iron
· Multimeter
· Tester
· Screw driver
· LED Chip
· Nose pliers
· Tweezer
Ø Repairing of LED bulbs : Open a non functioning bulb and examine the parts, rectifier, load resistor, filter capacitor, and LED chip using a multimeter to know whether the parts are functioning or not. Then replace the damaged part with new on.
Ø Scientific disposal of LED Bulbs : Divide the LED bulb's plastic, electrical, and metal components into their respective disposal units.
Other important links
Class10-Physics-Ch1-Effects
of Electric current - Main reference
Class10-Physics-Ch1-Effects
of Electric current - 1 mark expected question - page-1
Class10-Physics-Ch1-Effects
of Electric current - 1 mark expected question - page-2
Class10-Physics-Ch1-Effects
of Electric current - 2 mark expected questions
Class10-Physics-Ch1-Effects
of Electric current - 3 mark expected questions