问题
计算题
从收音机从盘面上可以看出,它能够接收的调频波(FM)频率范围为88MHz~108MHz,那么这个范围内的电磁波的波长在什么范围?
答案
解:当频率为88MHz时,对应的波长=3×108m/s÷(88×106Hz)≈3.41m;
当频率为108MHz时,对应的波长=3×108m/s÷108×106Hz≈2.78m.
故电磁波的波长范围为3.41m~2.78m.
从收音机从盘面上可以看出,它能够接收的调频波(FM)频率范围为88MHz~108MHz,那么这个范围内的电磁波的波长在什么范围?
解:当频率为88MHz时,对应的波长=3×108m/s÷(88×106Hz)≈3.41m;
当频率为108MHz时,对应的波长=3×108m/s÷108×106Hz≈2.78m.
故电磁波的波长范围为3.41m~2.78m.
在方框中选择一个适当的词或短语,将正确形式内填在下列各句的空格上
小题2:You are____ to finish the work with your team. 小题3:She said she wouldn’t make any _____ in the coming exam. 小题4:He often ______ money for me when I was poor. 小题5:It used to be______ for us to study English. |