Question

pla answer this class 10th electricity​

Answer 1

Answer:

As we know that KWh is equivalent to units consumed by any electrical appliances.

So, it can be written in equation form as-

1unit=1Kwh

=3.6×106J

.

So,1unit

consumes3.6×106J

of energy.

Here it is given in the question that geysers consume 2.2

units of electric energy.

So, 2.2units=2.2Kwh=2.2×3.6×106J

=7.92×106J

.

So, geysers consume 7.92×106J

of energy in 1 hour.

a).Work = Energy Consumed by geyser = 7.92×106J

Time of operating the device =1hr=3600s

As we know that,

∵Power=WorkTime=EnergyTime

∴Power=7.92×1063600

Power=2200Watt

So the power rating of this device is2200Watt

.

SI unit of power is Watt.

b).Let us assume the value of current isI

.

Voltage of mains supply is given =220V

Power consumed by device =2200Watt

∵P=VI

I=PV=2200220=10A

So current flowing through this device when it is connected to mains is10A

.

SI unit of Current in Ampere (A)

c).Let us assume the resistance of this device isR

.

Operating Voltage of device V=220Volt

Current Flowing through deviceI=10A

∵R=VI=22010=22Ω

So resistance of the device is22Ω

.

SI unit of resistance is Ohm(Ω)

d).As we know that Resistance and Temperature are directly proportional to each other, so if temperature of device will increase then its resistance will also increase and if it is decreased then resistance also gets decreased. So here the temperature of geysers will increase so its resistance to geysers will also increase. It can be expressed mathematically by the given equation.

Rt=R0(1+αΔT)

Where,

Rt

= Resistance of Conductor att0C

.

R0

= Resistance of Conductor at00C

α

= Temperature Coefficient.

ΔT

= Temperature difference.

e).As it is given in the question that ,

Cost of 1unit=Rs6

It is given that geysers consume 2.2units

of electrical energy.

So, Cost of 2.2units=2.2×6

=Rs13.20