Question

What are the practical applications of heating effect of electric current? Relate SI unit of energy with its commercial unit.(3 marks)

Answer 1

Answer:

The Electric Bulb: The filament bulb is such that the inner core filament (mostly tungsten as it does not melt easily) is heated up to a certain temperature after which it is illuminated.

The Electric Iron: Bimetallic plates and applying the heating effect of current helps the iron break the flow of electricity when a certain temperature is reached. you may have noticed this when the red light on an iron box comes on and off.

Electric Heater: Similar to that of an iron box but here, a circuit breaker is used

The Electric Fuse: Copper or zinc can be used as the fuse element. When there is an excess of current flow through the electrical circuit, the heat generated increases as well and melts the fuse, thereby breaking the circuit.

The amount of heat generated (H) is given by the following relation.

H ∝ I2Rt where,

I is the electric current through the component

R is the resistance

t is the time span of heat generation.

The SI unit of energy is Joule(J).

One kilowatt hr is the amount of energy consumed by an appliance in 1 he working at a constant rate of 1 kilowatt(I.e.,at the rate of 1000J in 1 second).

So,

1Kwh=1Kw ×1hr

1Kwh =1000W ×1hr

=1000J/s ×3600s

1Kwh=3600000=3.6 ×10 to power 6 J

Hope the answer helps u

Thank u

Answer 2

Answer:

For exploiting the heating effect of electric current, the element of appliances must have high melting point to retain more heat. The heating effect of electric current is used in the following applications: Electric Bulb: In an electric bulb, the filament of bulb gives light because of heating effect of electricity

Explanation:

the SI unit joule is too small to express very large quantities of energy. Hence we use a bigger unit called kilowatt hour (kWh) to express energy. 1 kWh is the amount of energy consumed by an electrical gadget in one hour at the rate of 1000 J/s or 1kW. The commercial unit of energy is kWh(kilo watt hour).