Answer:
1) ironing a shirt 2) writing on surfaces 3) working of an eraser
B b b b b b b bb bb bb b b b b b b b b b
They compress or expand depending on amount of pressure or depending on the temperature
Answer:

Explanation:
We are given that

Distance between the wires,
1mm=
Length of other wire,l=0.3 m
Length of one wire is infinite.
We have to find the magnitude of force between the two wires.
We know that magnetic force

Where 


When the wires carrying equal current in opposite direction then the force between two wires repel to each other.
Answer:
Ben's average speed was twice Debby's average speed.
Explanation:
Ben covered a total distance of 16 miles (10+4+2) and Debby covered 8 miles (3+2+2+1) which is half of what Ben covered. As they both reached the place in the same amount of time it tells us Ben was faster.