对电源变压器各绕组电压进行测量时,其输出的空载电压值()。
A.不允许超过标称值
B.应超过标称值的10%
C.略高于标称值但不超过10%
D.允许波动±7%
参考答案:C
A five-year bond with a 8.00 percent semiannual coupon currently trades atl02. 345 percent of a par value of $1000. Which of the following is closest to the current yield on the bond()
A. 3.91%.
B. 7.43%.
C. 7.82%.
有关地震波()
A.地震波是一种无线电波
B.纵波传播到古登堡面时完全消失
C.纵、横波波速在莫霍面都明显减小
D.从震源发出的地震波纵波比横波先到达地面