Electrical Engineering - Energy and Power - Discussion
Discussion Forum : Energy and Power - General Questions (Q.No. 7)
7.
A 15 V source is connected across a 12 
resistor. How much energy is used in three minutes?
resistor. How much energy is used in three minutes?Discussion:
31 comments Page 3 of 4.
Tejswee said:
1 decade ago
Energy = Power*Time = (i^2*r)*(3/60) = 0.9375
(1)
Ravi Purohit said:
1 decade ago
As per ohm's law,
R = V / I
I = V / R
= 15 / 12
= 1.25 A
And Power P = V * I
= 15*1.25
= 18.75 w
Given duration is 3 miniute i.e. 3 / 60 hour
Therefore, Watt-hour = 18.75 * (3 / 60) = 0.9375
R = V / I
I = V / R
= 15 / 12
= 1.25 A
And Power P = V * I
= 15*1.25
= 18.75 w
Given duration is 3 miniute i.e. 3 / 60 hour
Therefore, Watt-hour = 18.75 * (3 / 60) = 0.9375
RAFI said:
1 decade ago
Energy=power*time
p=v*I
p=v*(v/R)(i=v/r)
p=Vsquare/R
=15*15/12=18.75
NOW,ENERGY IN 3MINUTES=18.75*3=56.25WATT MINUTES
ENERGY IN HOUR=18.75*0.05=0.9375WATT HOUR(3MINUTES=0.05HOUR)
ANSWER IS B
p=v*I
p=v*(v/R)(i=v/r)
p=Vsquare/R
=15*15/12=18.75
NOW,ENERGY IN 3MINUTES=18.75*3=56.25WATT MINUTES
ENERGY IN HOUR=18.75*0.05=0.9375WATT HOUR(3MINUTES=0.05HOUR)
ANSWER IS B
Sudip said:
1 decade ago
P=VI
P=15*1.25=18.75
Total power = 18.75*3/60= .937
P=15*1.25=18.75
Total power = 18.75*3/60= .937
Namrata said:
1 decade ago
@Debu is correct.
Rajesh Kumar R said:
1 decade ago
Bains is correct.
Debu said:
1 decade ago
15v/12=1.25amps P=VI = 15*1.25=18.75W consumed in one hour So in 3 minute 3/60=.05 POWER IN THREE MINUTE=.05*18.75=.9375
BAINS said:
1 decade ago
15v/12=1.25amps P=VI = 15*1.25=18.75 , FOR TIME IN MINUTE 3/60=.05 POWER IN THREE MINUTE=.05*18.75=.9375
Muhammad Fayyaz said:
1 decade ago
@Ravi26v is right.
ARAMUTHAN said:
1 decade ago
Energy = Power x time (V=IR)--I = 15 V/12Ohms = 19.5
Energy = (1.25*15) x 3
Energy = 56.25 Wh so the answer should be C
Energy = (1.25*15) x 3
Energy = 56.25 Wh so the answer should be C
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