Explanation:
Given that,
Length of gold wire, l = 4 m
Voltage of battery, V = 1.5 V
Current, I = 4 mA
The resistivity of gold, 
Resistance in terms of resistivity is given by :

Also, V = IR
So,

A is area of wire,
, r is radius, r = d/2 (diameter=d)

Out of four option, near option is (C) 17 μm.
The answer is b i just did the test
The change in the internal energy of the system is 110 kJ.
<h3>What is internal energy?</h3>
Internal energy is defined as the energy associated with the random, disorder motions of molecules.
calculate the change in internal energy, we apply the formula below.
Formula:
- ΔU = Q-W.................... Equation 1
Where:
- ΔU = Change in internal energy
- Q = Heat absorbed from the surroundings
- W = work done by the system
From the question,
Given:
Substitute these values into equation 1
Hence, The change in the internal energy of the system is 110 kJ.
Learn more about change in internal energy here: brainly.com/question/4654659
Voltage = current x resistance
since R is doubled, current must reduce by half.
So,
new current = 120/2 = 60mA