Answer:
d. 2.3 ohms (5.3 amperes)
Explanation:
The calculator's 1/x key makes it convenient to calculate parallel resistance.
Req = 1/(1/4 +1/8 +1/16) = 1/(7/16) = 16/7 ≈ 2.3 ohms
This corresponds to answer choice D.
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<em>Additional comment</em>
This problem statement does not tell the applied voltage. The answer choices suggest that it is 12 V. If so, the current is 12/(16/7) = 21/4 = 5.25 amperes.
Answer:
The mechanical advantage is 3 to 1
Explanation:
A frictionless pulley with three support ropes carries equal tension on each of the ropes thus;
Tension in each pulley rope = T
Total tension in the 3 ropes = 3 × T = 3·T
Direction of the tension forces on each rope = Unidirectional
Total force provided by the 3 ropes = 3·T
Therefore, a force, T, applied at the end of the rope will result in a lifting force of 3·T
Hence, the mechanical advantage = 3·T to T which is presented as follows;
![Mechanical \ advantage = \dfrac{3 \cdot T}{T} = \dfrac{3}{1}](https://tex.z-dn.net/?f=Mechanical%20%5C%20advantage%20%3D%20%5Cdfrac%7B3%20%5Ccdot%20T%7D%7BT%7D%20%20%3D%20%5Cdfrac%7B3%7D%7B1%7D)
The mechanical advantage = 3 to 1.