Answer:
OT
It is important to wear protective equipments during games and practices.
Explanation:
Practice is a review of what is about to happen in some time to come and with practice ,the future can be trusted.
During practice it is very important to use protective gears or equipments because without them, injuries and accidents are liable to occur.
During the major game it is also important to prevent accidents or big injuries as the equipments protect each vital part of the body.
The air would contract therefore the answer is the second choice.
Answer:
Diameter will be 351.42 mm
Explanation:
We have given current flowing in the copper wire i = 310 A
Voltage drop across the wire V = 0.55 volt
We know that resistance is given by 
Length of the copper wire l = 1 m
Resisitivity of the copper wire 
We know that resistance 


As area 


So diameter
= 351.42 mm