An electric heater is rated 750W-200V. Calculate 1) resistance 2) current. If the heater is used to heat 400g of water at 20’C and switched on for 5 min. calculate the final temperature of water.
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0
Answer:
1) 160/3 ohms
Explanation:
1) P =
750 =
R = 160 / 3 Ω
Answered by
0
Answer:
Given
P=750W V = 200 V t= 5 min or 300 secs
R = V²/P
1)R = 200 x 200 / 750 = 53.33 ohm
I=P/V (P=VI)
2)I= 750/200= 3.75 Amphere
P = W/t, W=E=Q
Therefore, Q = P x t
Q = 750 x 300 = 225000 J
Q = mcΔt
Δt= Q/mc= 225000/400 x 4.2= 134 (round off)
Final temperature = Δt + intial temp = 134 + 20 = 154 k
Explanation:
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