An electric iron rated 250 V has a coil of resistance 125Ω. What is the cost of using it for I hour at 10k per kWh?

Theodoraumoh

2 years ago

Energy consumed = power × time
0.5kw × 1hr = o.5
i missed that in the pic

buster22

2 years ago

To find the cost of using the electric iron for 1 hour, we need to calculate the power consumption first.
The power
�
P consumed by the electric iron can be calculated using the formula:

�
=
�
2
�
P=
R
V
2

​


Where:

�
V is the voltage (250 V in this case).
�
R is the resistance (125 Ω in this case).
Substituting the given values:

�
=
25
0
2
125
=
62500
125
=
500
 
W
P=
125
250
2

​
=
125
62500
​
=500W

Now, we can calculate the energy consumed in 1 hour (in kWh):

Energy
=
�
×
time
1000
Energy=
1000
P×time
​


Substituting
�
=
500
 
W
P=500W and time = 1 hour:

Energy
=
500
×
1
1000
=
0.5
 
kWh
Energy=
1000
500×1
​
=0.5kWh

Now, we can calculate the cost:

Cost
=
Energy
×
Cost per kWh
Cost=Energy×Cost per kWh

Substituting the energy consumed (0.5 kWh) and the cost per kWh (10k):

Cost
=
0.5
×
10
=
5
�
Cost=0.5×10=5k

So, the answer is C. 5.00k

Emedion

9 years ago

Here is an explanation:

Given The Above Parameters.Calculate Your Current I From Ohm's Law V=IR.The Next Step Is To Substitute The Value Of I Into The Equation P=IVt In Order To Calculate Your Power Leaving Your Answer In Kilowatts.Multiply Your Calculated Power By 10 Since 1 Hour Costs 10 Kwh

Noblembachu

4 years ago

the ans. is 20k