The simple machine used is called atwood machine.
Answer:
C. Water passes into the salt solution, dehydrating bacterial cells and making them harmless.
Explanation:
The salt solution is hypertonic to the bacterial cells and as such, water molecules will move from the bacterial cells into the salt solution, dehydrating the cells and rendering them harmless.
Option A is also true but it is irrelevant to the question asked. Option B and D are wrong.
The correct option is C.
<span>a narrow, variable band of very strong, predominantly westerly air currents encircling the globe several miles above the earth. There are typically two or three jet streams in each of the northern and southern hemispheres.</span>
Answer: Option (c) is the correct answer.
Explanation:
When current passes through a wire then a magnetic field is formed. Therefore, when two wires carry current in the same direction then both the wires with have respective magnetic fields in the same direction and their total magnetic field will be large.
But when current between two wires flow in opposite direction then the magnetic field produced will also be in opposite direction. Therefore, both the magnetic fields cancel each other out. Thus, total magnetic field will be small.
As a result, wires which carry current in the opposite direction repel each other.