Question

10 electric lamp of 100 watt is used for 5hours per day calculate the units of
energy

consumed by lamp in oneday


a.15units

b.20units

c.5unit

d.10unit​

Answer 1

Given:-

• Number of lamps=10

• Power of 1 lamp=100 watt

• Time for which each lamp used is one day=5 hrs

To find:-

• Energy consumed by lamp in one day

Solution:-

Power of 1 lamp=100 watt

Power of 10 lamp=100×10 watt=1000 watt

Time for which 1 lamp used=5 hrs

Total time for which 10 lamp used=5×10hr=50 hrs

Now we are applying formula for power:

⇒ E=P×t

Here:-

• P=power

• E=Energy

• t=time

Now substituting given values in formula:

⇒ E=1000 watt×50hrs

⇒ Energy=50000 Watt.hr

Now we have to convert it into standard unit or kilowatt hr, so we will divide it by 1000.

⇒ Energy=50000 ÷1000 KiloWatt.hr

⇒ Energy=50 KiloWatt.hr

• 1 kilowatt hr=1 unit

• 50 kilowatt hr=50 units

∴ So the required energy consumption is 50 units.