Answer:
B. $5.18
Explanation:
Cost of electricity per kWh = $0.09
Power consumption of refrigerator = 320W = 320/1000 = 0.32kW
In a month (30 days) the refrigerator works 1/4 × 30 days = 7.5 days = 7.5 × 24 hours = 180 hours
Energy consumed in 180 hours = 0.32kW × 180h = 57.6kWh
Cost of electricity of 57.6kWh energy consumed by the refrigerator = 57.6 × $0.09 = $5.18
Answer:
V=L(di/dt) where i is current, V=0.208
Explanation:
using expression iL(t)=5e-2t+3te-2t-2 and L=0.05H(50/1000)
V=0.05*d(5e-2t+3te-2t-2)/dt
since there is no power of e, I'll assume the power to be 1
V=0.05*(-2+3e-2)
at t=0.25
V=0.15e-0.2
V=0.208
Answer:
The surface temperature of the ground is = 296.946K
Explanation:
Solution
Given
r₁= 0.05m
r₂= 0.08m
Tn =Ti = 77K
Ki = 0.0035 Wm-1K-1
Kg = 1 Wm-1K-1
Z= 2m
Now,
The outer type temperature (Skin temperature pipe)
Q = T₀ -T₁/ln (r2/r1)/2πKi = 2πKi T0 -T1/ln (r2/r1)
Thus,
10 w/m = 2π * 0.0035 = T0 -77/ln 0.08/0.05
⇒ T₀ -77 = 231.72
T₀= 290.72K
The shape factor between the cylinder and he ground
S = 2πL/ln 4z/D
where L = length of pipe
D = outer layer of pipe
S = 2π * 1/4 *2/ 2 * 0.08 = 1.606m
The heat gained in the pipe is = S * Kg * (Tg- T₀)
(10* 1) = 1.606 * 1* (Tg- 290.72)
Tg - 290.72 = 6.2266
Tg = 296.946K
Therefore the surface temperature to the ground is 296.946K
Answer:
minimum radius of bend.
Explanation:
The sharpest bend that can be placed in a piece of metal without critically weakening the part is called the minimum radius of bend.
