【单选题】在电动势为3V的电路中,用3个相同电阻组成先并联后串联电路,要想得到2A的总电流强度,单个电阻的阻值应为()Ω。
【单选题】把两个阻值相同的电阻串联起来接入电路中,两电阻消耗的总功率为 P 1 ,若将这两个电阻并联起来接入同一电路中,两电阻消耗的总功率为 P 2 ,则 P 1 与 P 2 之比为 。
【单选题】What is the main idea of the text?
A.
Recycling of electronic items is a 'success story'.
B.
Environmentalists are opposed to recycling electronics.
C.
Recycling can not keep pace with electronics sales.
D.
It is unnecessary to recycle electronics.
【单选题】Which of the following statements best describes the main idea of Success for Teens ?
A.
Good habits somewhat help but don’t promise success.
B.
Bad habits constantly hold teens back.
C.
Possibly it takes longer to develop a good habit than to get rid of a bad one.
D.
Certain useful tips that teens can implement will help them develop good habits.
【单选题】两个阻值相同的电阻,串联接入电源时,电路中的总电流为1A,若将它们改成并联,接入同一电源中,则电路中的总电流是()
【判断题】变压器等效电路的串联和并联表示的激磁回路中,激磁电阻和铁耗电阻值相同。
【单选题】Java中main()函数的返回值是( )。
【单选题】在电动势为3V的电路中,用3个相同电阻组成先并联后串联电路,在不计内阻的情况下,要想得到2A的总电流强度,单个电阻的阻值应为()。