Paper 1 October/November 2022 Combined Science (0653/13) IGCSE
Cambridge
IGCSE
Science Combined (0653)
بهمن
2022
شامل مباحث:
تعداد سوالات: 40
سطح دشواری:
متوسط
شروع:
آزاد
پایان:
آزاد
مدت پاسخگویی:
45 دقیقه
پیش نمایش صفحه اول فایل
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?