Answer: Capacitor
Explanation:
Given the following ;
At time, t = T/4 ; I = 0
At time, t = T/2 ; I = - Imax
Where T = period
We can confirm what the unknown element is by using the relation, such that the parameters satisfy the stated condition ;
Recall;
I = Iosin(wt + π/2) [for CAPACITOR]
w = 2π/T
At t = T/4
I = Iosin(2π/T(T/4) + π/2)
I = Iosin(π/2 + π/2)
I = Iosin(0)
I = 0
At t = T/2
I = Iosin(2π/T(T/2) + π/2)
I = Iosin(π + π/2)
I = Iosin(0)
I = Iosin(3π/2)
I = Iosin(540/2)
I = Iosin(270)
I = -Io
Note : Io = Imax
Both conditions are met, Hence, the unknown element is a CAPACITOR.
Answer:
Explanation:
Given
length=8 m
width=4 m
deep=4 m
Area of base 
hydro static Pressure on bottom

Force on bottom
Now pressure at the side wall

where
is the mean length of wall = 4 m

The type of ions that electrons collide with to cause resistance in a circuit is B. Metallic
Answer: Option (a) is the correct answer.
Explanation:
When gases, liquids, or solids are in contact with a moving object then friction occurs due to the movement of objects in opposite directions.
During this opposite movement, bonds between the molecules of respective objects break and again their is formation of new bonds.
This breaking or making of bonds results in the formation of energy in the form of heat.
Thus, we can conclude that when gases, liquids, or solids are in contact with a moving object, the flow of heat occurs due to frictional forces.