Concept explainers
(a)
The magnitude and direction of the field due to the charges.
(a)
Answer to Problem 74E
The magnitude of net electric field above the surface of the earth is
Explanation of Solution
“The electric force per unit charge is defined as the electric field”.
The expression for the electric field due to a point charge is as follows:
Here,
Analogous to equation (I), the electric field at the surface of the earth just below the cloud due to the charge
Here,
Analogous to equation (I), the electric field at the surface of the earth just below the cloud due to the charge
Here,
Write the expression for the net electric field.
Here,
Use equation (II) and (III) in equation (IV).
Conclusion:
Substitute
The direction of the electric field due to both the charges at the surface of the earth is downward.
Therefore, the magnitude of net electric field above the surface of the earth is
(b)
The locations and values of the image charges corresponding to the
(b)
Answer to Problem 74E
The locations and values of the image charges corresponding to the
Explanation of Solution
The image charge for
Conclusion:
The image charge for
(c)
The total electric field due to all the charges at the surface of earth just below the cloud.
(c)
Answer to Problem 74E
The total electric field due to the charges at the surface of the earth just below the cloud is
Explanation of Solution
“The electric force per unit charge is defined as the electric field”.
The expression for the electric field due to a point charge is as follows:
Here,
Write the expression for the electric field due to the charges
Here,
Write the expression for the electric field due to the charges
Here,
Write the expression for the total electric field.
Here,
Use equation (V) and (VI) in equation (VII).
Conclusion:
Substitute
Therefore, the total electric field due to the charges at the surface of the earth just below the cloud is
(d)
Whether the lightning from this cloud strike the ground or not.
(d)
Answer to Problem 74E
No, the lightning will not strike the ground.
Explanation of Solution
The total electric field due to all the charges is less than the electric field generated by the air as a conductor. Since the electric field due to all the charges is less than the electric field generated by the air as a conductor, the cloud lightning does not strike the ground.
Conclusion:
Since the electric field due to all the charges is less than the electric field generated by the air as a conductor, the cloud lightning does not strike the ground.
Therefore, the lightning from the cloud does not strike the ground.
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Chapter 16 Solutions
General Physics, 2nd Edition