The rated voltage is 220 V ~, the rated frequency is 50 Hz, and the rated total input power is 2000 W. what kind of patch board is better

The rated voltage is 220 V ~, the rated frequency is 50 Hz, and the rated total input power is 2000 W. what kind of patch board is better

The rated current of 10A is OK. However, it is recommended that you choose carefully when purchasing. Don't choose the one with poor quality - this kind of contact resistance is big. Bull is good. If you have silver contact, it's best

A few days ago, Xiao Liang's mother bought an "Tianji" brand automatic electric kettle for her grandfather, whose name plate is as shown in the right watch (220 V, 50 Hz, 1100 w)
A few days ago, Xiaoliang's mother bought an "Tianji" brand automatic electric kettle for her grandfather. Its name plate is like the right watch (220 V, 50 Hz, 1100 w). After receiving 800 ml of water, the water boils 5 minutes later, and the power is cut off automatically. The initial temperature of the water is 20 ° C
(1) Water absorbs heat
(2) If the voltage in the home is 220 V, calculate the thermal efficiency of the electric kettle (keep two decimal places)
(3) The actual voltage drop is 198v. What is the actual power of the electric kettle?

(1) Water mass m = v = 1g / cm3 × 800 cm3 = 800g = 0.8kg (1 point)
The heat absorbed by water is q = cm (t-t0) = 4.2 × 103J / (kg ·℃) × 0.8kg × (100 ℃ - 20 ℃) = 2.7 × 105J
(2 points)
(2) The electric energy consumed by electric kettle is w = Pt = 1100W × 300s = 3.3 × 105J (2 points)
η = q absorption / W electricity = 2.7 × 105J / 3.3 × 105J = 81.8% (1 point)
(3) Resistance of electric kettle r = U2 / P = (220V) 2 / 1100W = 44 (2 points)
Actual power P = U2 / r = (198v) 2 / 44 = 891w (2 points)

In the exchange activities with foreign high school students, Xiao Ming brought back an electrical appliance from abroad, with rated voltage of 110V and rated power of 25W
An electric appliance with rated voltage of 110V and rated power of 25W can not be used because it can not adapt to the 220 V grid voltage in China. It is suggested that the electric appliance should be connected in series with a "220 V, 100 W" incandescent lamp and then connected into the 220 V circuit
A. The electric appliance can work normally; B. the actual voltage borne by the electric appliance will be higher than 110V; C. the actual voltage borne by the electric appliance will be lower than 110V; D. the actual power of the incandescent lamp will be greater than 25W

I have worked, with the remaining problem-solving skills, come to the conclusion: the actual power of incandescent lamp is less than 25W
The normal resistance of incandescent lamp is R1, and the resistance is R (0

Japanese friends gave Xiaohong's father two electric kettles, the specifications of which are "110V, 500W" and "110V, 100W", but they can't be used in our country's home circuit alone. Xiaohong thought: since the rated voltage of the two electrical appliances is 110V, then they can be connected in series and then connected to the home. ① is Xiaohong's method OK? Why? ② If you want to use the "110V, 500W" electric kettle normally, what should you do?

(1) R1 = u2p1 = (110V) 2500W = 24.2 Ω, R2 = u2p2 = (110V) 2100W = 121 Ω. I = u1r1 + R2 = 220v24.2 Ω + 121 Ω = 1.5A, U2 = IR2 = 1.5A × 121 Ω = 181v, which can not be connected in this way