Question

4. An electric heater consumes 5 A of current
when run on 220 V mains. Find the cost of
running it for 7 hrs. when the electric energy
is supplied at 30 paise per unit?
​

Answer 1

Answer:

Power = VI

= 220 × 5 = 1100 watt

= 1.1 kw

Cost per hour = 1.1 × 6

= 6.6

Explanation:

hope it helps u..

Answer 2

Answer:

Here, Heat energy consumed $\large\rm { = P = 2kW = 2000W \ and \ time \ = t = 10 \ hour = 36000s }$

$\large\rm {P = \frac {E}{t}}$

$\large\rm { → E = Pt = 2kW \times 10h = 20kWh = 20 units }$

$\large\rm {( Since \ 1 \ unit = 1 \ kWh)}$

$\large\bf { cost = 20 \times 30 = ₹600}$