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:
32 comments Page 2 of 4.
Naser said:
1 decade ago
15*15/12 = 18.75.
18.75/60 = 0.3125.
0.3125*3 = 0.9375 wh.
18.75/60 = 0.3125.
0.3125*3 = 0.9375 wh.
Pankaj R.Patil said:
1 decade ago
v^2/r*t, t in hours.
RAVI said:
1 decade ago
15/12 = 1.25 A.
3/60 = 0.05 H.
P = 15*1.25 = 18.75 W.
E = 18.75*0.05 = 0.9375 WH.
3/60 = 0.05 H.
P = 15*1.25 = 18.75 W.
E = 18.75*0.05 = 0.9375 WH.
Zahid said:
10 years ago
Well said @Bains and @Debu.
Satish mahadu kukade said:
9 years ago
You are correct @Debu.
Gaikwad.pravin said:
8 years ago
Here, it is (v^2/R) *3.
Pranu said:
1 month ago
energy = power * time.
= v * I * t.
= v * (v/r) * t.
= 15 * (15/12) * (3/60).
= 0.938Wh.
= v * I * t.
= v * (v/r) * t.
= 15 * (15/12) * (3/60).
= 0.938Wh.
Ravi26v said:
2 decades ago
((V*V)/ R)*time in hrs
BIPRADAS GHOSH said:
1 decade ago
Energy = (I)2Rt.
I = V/R = 15/12 = 1.25.
R = 12 and t = 3 min = 3/60 hr = 0.05 hr.
So, Energy = (1.25)2*12*0.05 = 0.9375.
I = V/R = 15/12 = 1.25.
R = 12 and t = 3 min = 3/60 hr = 0.05 hr.
So, Energy = (1.25)2*12*0.05 = 0.9375.
Mrakovic said:
1 decade ago
W = U^2/R.
W = 225/12 = 18.75W.
3 min = 0.05h.
Wh = W*t = 18.75*0.05 = 0.9375Wh.
W = 225/12 = 18.75W.
3 min = 0.05h.
Wh = W*t = 18.75*0.05 = 0.9375Wh.
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