Login/Sign Up
a) An electric iron is rated at 230V, 750W. Calculate i) the maximum current, ii) the number of units of electricity it would use in 30 minutes. b) Which of the following fuse ratings would be suitable for this electric iron? 1A, 3A, 5A, 13A.
a) An electric iron is rated at 230V, 750W. Calculate i) the maximum current, ii) the number of units of electricity it would use in 30 minutes. b) Which of the following fuse ratings would be suitable for this electric iron? 1A, 3A, 5A, 13A.
CBSE | Class 10 | Lakhmir Singh | Magnetic Effects of Electric Current | Physics
a) An electric iron is rated at 230V, 750W. Calculate i) the maximum current, ii) the number of units of electricity it would use in 30 minutes. b) Which of the following fuse ratings would be suitable for this electric iron? 1A, 3A, 5A, 13A.

Solution:

a) Given, V = 230V

P = 750W

T = 30/60 = 0.5 hours

i) Let the maximum current be I

As we know that,

P = VI

Evaluating value of current,

750 = 230I

I = 3.26A

ii) Electric energy consumed, E = PT

E = 0.75kW×0.5 hours

E = 0.375 kWh

Therefore, the number of units used in 30 minutes = 0.375

b) For example, the electric iron will require a fuse with a current rating of 5A because the maximum current for the specified iron is 3.26A.

i

More Material