A wave completes 20 oscillations in 4 seconds. Frequency is MCQ with Answer and Explanation

Explanation:
Ice displaces water equal to its weight. When melted, it occupies exactly that volume. So level unchanged. Classic question.

Explanation:
In the SI system of prefixes, 'Peta' stands for 10^15. Other common large prefixes include Kilo (10^3), Mega (10^6), Giga (10^9), Tera (10^12), and Exa (10^18). It's crucial to memorize both positive and negative powers (like nano, pico, femto) for competitive exams.

Explanation:
Thermostat uses differential expansion to make/break circuit.