Question Continuation
True or False?
Answer:
False
Explanation:
Given
Columns: book_title and year_released
SQL statement: SELECT book_title, year_released FROM books GROUP BY year_released
Expected Result: To select the number of books released each year
Although the GROUP BY used in the SQL statement is meant to group rows with same values into summary rows but it's not user properly because the GROUP BY clause, as used here needs the COUNT aggregate functions to group the result-set by one or more columns.
Answer:
Average power dissipated by the 700-Ω resistor=47W
Explanation:
average power dissipated by the 700-Ω resistor
=47W
Answer:
No, the claim is not reasonable for 20 W electric power consumption.
It is reasonable for 40 W electric power consumption.
Explanation:
Power = (1/2)*mass flow rate*(square of velocity)
mass flow rate = 1 kg/s
velocity = 8 m/s
square of velocity = 64 m^2 / s^2
Power = (1/2)*(1)*(64)
Power = 32 W
For a fan that consumes 20 W power it is not possible to deliver more power than 20 W but this one is delivering 32 W hence it is a false claim.
For a fan that consumes 40 W it is indeed possible to deliver 32 W considering the efficiency. Hence this claim is reasonable.