Yes it had in the history more than once.
- Sweden had 30 days in the month of February while changing from Julian to Gregorian calendar in 1712 .
- Soviet Union had 30 days in the month of February in 1930 and 1931 while following thier revolutionary calender which had 30 days for all months and some holidays which didn't come in any of the month.
- Also an unverified info said that during 45 BC to 8 BC all the leap year February months had 30 days.
Electrical device is the one which contains passive components like wires, resistors, etc for which the output is always not greater than the input (which does not amplify) and does not require any power supply for thier own functioning. Eg. Iron box.
Electronic Device is the one which has active components like transistors, ICs etc which may or may not amplify depending upon the functional design and which requires power supply for its own working. Eg: Mobile Phone.
- Arun