Question

6. An electric iron has a rating of 750W,220V. Calculate : a) current passing through it and
b) its resistance when in use.
7. Two lamps , one rated 100W at 220V and other 40 W at 220V are connected parallel to 220V mains supply. Calculate the current drawn from the supply line.
8. An electric lamp is marked 100W,220V.It is used
for 5 hours daily.Calculate:
a)Its resistance when in use.
b)Energy consumed in KWh per day.
9.two resistors of resistance 3 ohm and 6 ohm respectively are connected to a battery of 6V so as to have
a) Min resistance

Answer 1

6.
a) Power (watts) P = V * I
I = P/V
b) \[P=I ^{2}R\]
\[R=\frac{P}{I ^{2}}\]
7.
Calculate current for ewach lamp using I = P/V and add the two values of current to find the total current.
8.
a) Current I = P/V
\[R=\frac{P}{I ^{2}}\]
b) 100W = 0.1kW
Energy = 0.1 * 5 kWh per day
9. Connecting the resistors in parallel gives minimum resistance.

Answer 2

* for each lamp

Answer 3

thank you for your guidance kropot72.

Answer 4

You're welcome :)

Answer 5

could you explain Q9. again, please?

Answer 6

Q9 is not the full question? Please check.

Answer 7

actually, I had reached the limit of the page, so I could type no more.

Answer 8

You can post it as a new question.

Answer 9

yes, I will.Thank you.