Electronics - Ohm's Law - Discussion

40W * 1750hr/ 1000 = 70W or 40W is converted into KW i.e 0.04KW * 1750 = 70W.

We know that,

P = W/T.
or W = P*T = 40*1750 = 70000watt-h.
= 70kwatt-h.

1 KW/1000 W = 40 W/ x W.

Solve for x and you'll get the number of watts.

x= 40 w * 1750 hr ( the hrs that the lamp remain on).

= 70 Whr.

I think this is as simple as that.

We know that 1 kilowatt = 1000 watt.

So, 40 watt = 40/1000 = 0.040 kilowatt.

Now as per the formula, 0.040 X 1750 = 70 (Answer).

Here he gives us kwh consumption it means 1000---->1hr.

So for making 40 watt to 1000 watt we need to multiply.

40*25----->1000.

It means if a light having 40 watt for 1750 hr.

We need divide the term with multiple term.

40 * 25 * x = 1750 * 40.

x = 1750 / 25.

x = 70.

Here the problem asked is Kilowatt-hour consumption. So,the formula is (no.of kilo watts * no.of hours).

But we have the power of bulb in watts , so we need to change into kilowatts.
multiply and divide the numerator by 1000,

Hence, (40*1750)*1000/1000 watts.

this implies , [(40*1750)/1000]KILOWATTS,wherein one kilowatt=1000 watts
as the question asked was kilowatt-hours.

How do you solve this problem?

I do not understand. Please give me a deep explanation.