When you rub a balloon on a sweater, for example, some electrons come off and end up on the balloon. The fibers have lost electrons giving them a positive charge. The rubber gained electrons giving it a negative charge. ... The positively charged fibers are now attracted to the negatively charged balloon.
I think it is b , that what I would i pick
Except when necessary for takeoff and landing, <span>the minimum safe altitude required for a pilot to operate an aircraft over other than congested area is an altitude of 1000 ft above the highest obstacle within a 2000 ft horizontal radius of the aircraft.
It is also good to know that apart from taking off and landing, the aircraft must not operate at a distance less than 500 ft from any person, vessel, structure or vehicle.</span>
Answer: matter is anything that has mass and volume
Explanation:
Answer:1200 kg
Explanation:
Given
Electromagnet can lift a mass of 
Magnetic force necessary to hold mass is proportional to Magnetic field
and magnetic field (B) is proportional to NIA
where N=no of turns
I=current in the magnet
A=area of cross-section
When we double the no of turns and triple the current then
N becomes 2 N
I becomes 3 I
therefore magnetic field becomes 6 times
Thus magnetic force becomes 6 times and we can say that electromagnet can hold the 6 times of given weight
i.e. 
