Resistance is the ratio of
(voltage between two points in the circuit)
divided by
(current between the same points).
It's expressed in units of Ohms, so the correct choice is "none of the above".
The distance of the object from the lens is 3.12 cm.
<h3>What is magnification?</h3>
Magnification is the process of of enlarging an apparent size of an object.
<h3>Object distance</h3>
The object distance is calculated using the following lens formula;
![M = \frac{V}{U}](https://tex.z-dn.net/?f=M%20%3D%20%5Cfrac%7BV%7D%7BU%7D)
where;
- M is the magnification
- V is the image distance
- U is object distance
![- 8 = \frac{-25}{U} \\\\U = \frac{-25}{-8} \\\\U = 3.12 \ cm](https://tex.z-dn.net/?f=-%208%20%3D%20%5Cfrac%7B-25%7D%7BU%7D%20%5C%5C%5C%5CU%20%3D%20%5Cfrac%7B-25%7D%7B-8%7D%20%5C%5C%5C%5CU%20%3D%203.12%20%5C%20cm)
Thus, the distance of the object from the lens is 3.12 cm.
Learn more about object distance here: brainly.com/question/24894435
It would connect the Earth of the device to Live, causing the metal casing of the device to become Live, touching it would cause a serious electrical shock.
Answer:
1681714.28571 N/C
Yes it could exist
Explanation:
m = Mass of housefly = 12 m
q = Charge = 70 pC
g = Acceleration due to gravity = 9.81 m/s²
E = Electric field
When an object accumulates charge it means that it is gaining electrons making it negatively charged. This is the concept of static electricity.
Here, the electric force and the graviational force will balance each other
![F_e=W\\\Rightarrow qE=mg\\\Rightarrow E=\frac{mg}{q}\\\Rightarrow E=\frac{12\times 10^{-6}\times 9.81}{70\times 10^{-12}}\\\Rightarrow E=1681714.28571\ N/C](https://tex.z-dn.net/?f=F_e%3DW%5C%5C%5CRightarrow%20qE%3Dmg%5C%5C%5CRightarrow%20E%3D%5Cfrac%7Bmg%7D%7Bq%7D%5C%5C%5CRightarrow%20E%3D%5Cfrac%7B12%5Ctimes%2010%5E%7B-6%7D%5Ctimes%209.81%7D%7B70%5Ctimes%2010%5E%7B-12%7D%7D%5C%5C%5CRightarrow%20E%3D1681714.28571%5C%20N%2FC)
1681714.28571 N/C of electric field would be required to levitate
The direction of the electric field would be upwards vertically.
In air the critical value of electric field is
which is more than the critical value of electric field in air. So, the electric field can exist.