Answer:
At twice the distance, the strength of the field is e/4
Explanation:
F = the strength of an electric field.
F is inversely proportional to the squared distance from the point charge.
mathematically,
F = k(e/d²)
hence, if d is doubled,keeping other forms constant
F = e/4,
Answer:

Explanation:
The resistance of a metal rod is given by

where
is the resistivity
L is the length of the rod
A is the cross-sectional area
The resistivity changes with the temperature as:

where in this case:
is the resistivity of silver at 
is the temperature coefficient for silver
is the current temperature
Substituting,

The length of the rod changes as

where:
is the initial length at 
is the coefficient of linear expansion
Substituting,

The cross-sectional area of the rod changes as

So, substituting,

Therefore, if the initial resistance at 21.0°C is

Then the resistance at 180.0°C is:

The correct answer from the choices listed above is the first option. The statement that is true would be that c<span>ompound AB has chemical and physical properties that are completely different from those of A and B. They completely different substances with different properties.</span>