An electronic circuit in a fire alarm makes a loudspeaker vibrate alternately at two different frequencies.
Which pair of frequencies is suitable to use in the alarm to alert people to the danger of fire?
1 )
1.5Hz and 15Hz
2 )
15Hz and 150 000Hz
150Hz and 15 000Hz
4 )
150000Hz and 15000000Hz
تحلیل ویدئویی تست
منتظریم اولین نفر تحلیلش کنه!