The size of a household electric iron is 220 V 800 W. it can generate J heat and use kwh electric energy after 10 minutes of normal operation

The size of a household electric iron is 220 V 800 W. it can generate J heat and use kwh electric energy after 10 minutes of normal operation

J = I square RT = 3.64 * 3.64 * 60 * 10 = 6691 kJ (I = P / u = 800 / 220 = 3.64A; r = u / I = 220 / 3.64 = 60 Ω)
W=PT=0.8（KW）*10/60=0.133A
For copper wire and aluminum wire with the same length and cross-sectional area, whose resistance is higher?
The resistance of aluminum wire is high! The unit resistance of silver in metal is the smallest and the conductivity is the best
A 1000 watt bulb consumes one kilowatt hour, and how many kilowatt hours does a 36 watt bulb consume?
One kilowatt hour is equal to 1 degree, 1000 * 1 = 1000 watt hour = 1 degree, 36 * 1 = 36 watt hour = 0.036 degree
Three phase 18 kW air switch
Three phase five wire 18 KW electric oven, how much air switch do you need? Thank you for your reply
The electric oven is connected by star connection, and the current is:
18*1000/（3*220）=27（A）
Use 30A air switch
If copper and aluminum wires of the same length have the same resistance, then ()
A. Copper wire should be thinner. B. aluminum wire should be thinner. C. copper wire and aluminum wire have the same thickness. D. their thickness cannot be compared
The factors influencing the resistance are the material, length and cross-sectional area of the conductor. If copper wire and aluminum wire of the same length have the same resistance, the conductivity of copper is better than that of aluminum, the resistivity of copper is smaller, and the cross-sectional area of copper wire is smaller
Is it 1000 watts per hour?
One kilowatt hour = 1000 watt hours
How much air switch and insurance does a 15 kW motor need
If it is a three-phase motor, 2 amperes per kilowatt, 30 amperes for 15 kilowatts, select d30 air switch. If it is a single-phase motor, select D63 amperes air switch. The fuse is selected according to 1.5-2 times of the rated current. 60 amperes for three items and 120 amperes for single item
What is the concept that the resistivity of copper wire exceeds 3% of the standard resistivity?
When r = ρ L / s, the resistivity increases by 3%, which means that the cross-sectional area of copper wire decreases by 3%, and the radius of copper wire shortens by 1.73%
"The resistivity of copper wire is 3% higher than the standard resistivity"
It may be due to the purity of the material used to make the wire - because the number of free carriers in the wire is reduced.
A 1000 watt electric appliance consumes one kilowatt hour. How much electricity does a 3000 Watt electric appliance consume in 15 minutes?
The power consumption is 1.5 degree in half an hour and 0.75 degree in 15 minutes
Can a 20 kW three-phase motor be directly controlled by a 60 a air switch?
It doesn't start very often
It's not easy to use, it will over-current when starting. It's better to use 100A air switch, star delta starting or step-down starting