Cho sơ đồ chỉnh lưu hình tia 3 pha làm việc ở chế độ nghịch lưu phụ thuộc như hình 2-07-C2. Biết
ua=220
2
sin100t(V), ub=220
2
sin(100t-2/3)(V),
uc= 220
2
sin(100t+2/3)(V), La=1mH, E =-200V,
R = 2, L = ,  = 2
0
, Id = 27,2A. Hãy:
a) Xác định góc điều khiển .
b) Vẽ dạng sóng điện áp trên tải u’d.

We want to calculate the total metabolic heat generated by a singing canary taking into account heat transfer by radiation, convection and exhaling air. the air temperature is 20 oc, canary’s body internal and surface temperature is 33oc, external body surface convective heat transfer coefficient is 25.2 w/m2 .k, temperature difference between the inhaled and exhaled air is 4.3 oc, the ventilation rate is 0.74 cc of air per second, specific heat of air is 1.0066 kj/kg.k and density of air is 1.16 kg/m3 . assume the canary’s body to be a cylinder with 7 cm diameter and 9 cm length, and heat exchange is from the side as well as the top and bottom of cylinder. calculate 1) the net rate of heat lost by radiation, assuming heat gained by the bird through radiation from the surroundings is 11.5 w; 2) rate of heat transferred by convection to the surrounding air; 3) rate of heat transferred in the exhaling air without considering any internal evaporation; 4) total metabolic power.

*drag each tile to the correct location in the sequence* the table shows chronological events in the life of our sun, a medium-sized star. place the missing events into the correct rows of the table.

In order of decreasing light-transmitting capabilities of materials, which is the correct sequence? a. transparent -> translucent -> opaque b. opaque -> transparent -> translucent c. opaque -> translucent -> transparent d. translucent -> transparent -> opaque