D.
Always use the right tool to get accurate measurements
Answer:
temperature measures heat - the unit is Celsius - and it is measured with a thermometer.
length is measuring how long, tall, or wide something is - the base unit it metres - and it is measured with a ruler or a metre stick
volume is measuring the quantity of a three dimensional space - the unit is cubic centimetre - you find volume by taking the measurements with a ruler
mass is measuring how much space something takes up/ weight - unit is the gram - you use a scale
I guess the correct answer is the first one.
Answer:
Motors commonly contain a "commutator" which allows a magnetic field due to a loop of wire to always be in a say "clockwise or counterclockwise" direction even tho the loop of wire is rotating.
That means that magnetic field due to the surrounding magnets is always in the same direction, but the magnetic field due to the rotating loop of wire is continually changing so that it will always oppose the surrounding field which remains in a constant direction.
This is most easily seen in a "DC - direct current motor".
