Answer:
The correct answer should be
A. 20 Joules
Explanation:
I'm taking the K12 Unit Test: Energy - Part 1 right now
Answer:
C) upward
Explanation:
The problem can be solved by using the right-hand rule.
First of all, we notice at the location of the negatively charged particle (above the wire), the magnetic field produced by the wire points out of the page (because the current is to the right, so by using the right hand, putting the thumb to the right (as the current) and wrapping the other fingers around it, we see that the direction of the field above the wire is out of the page).
Now we can apply the right hand rule to the charged particle:
- index finger: velocity of the particle, to the right
- middle finger: direction of the magnetic field, out of the page
- thumb: direction of the force, downward --> however, the charge is negative, so we must reverse the direction --> upward
Therefore, the direction of the magnetic force is upward.
Input heat, Qin = 4 x 10⁵ J
Output heat, Qout = 3.5 x 10⁵ J
From the first Law of thermodynamics, obtain useful work performed as
W = Qin - Qout
= 0.5 x 10⁵ J
By definition, the efficiency is
η = W/Qin
= 100*(0.5 x 10⁵/4 x 10⁵)
= 12.5%
Answer: The efficiency is 12.5%
In a series circuit, all of the components are connected in the same 'loop' and the current only has one direction/path it can flow through.
In the first three options, the current has multiple paths it can go through. So these three circuits are parallel and not series.
In the last option, the current only has one path where it can flow through, so that circuit is in series.
So Circuit <u>D </u>is a series circuit.
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Answer
Circuit D
