Question

20. In which of the following cases more electrical energy is consumed per hour?

1. A current of 1 ampere passed through a resistance of 300 ohms

2. A current of 2 amperes passed through a resistance of 100 ohms.

Answer 1

If current is represented as 'i' resistance as 'r', and time 't', then electrical energy e is defined
as,
$e = {i}^{2} \times r \times t$

(Note: time in seconds = t*60 )

first case:
1*1*300*1*60
=18000 Joule

second case:
2*2*100*1*60
= 24000 Joule

Thus second case consumed more in a hour.

Answer 2

Explanation:

1.

If current is represented as 'i' resistance as 'r', and time 't', then electrical energy e is defined

as,

e = {i}^{2} *r *t

(Note: time in seconds = t*60 )

first case:

1*1*300*1*60

=18000 Joule

second case:

2*2*100*1*60

= 24000 Joule

Thus second case consumed more in a hour.