<h3>Answer:</h3>
1. Resistance is the opposition offered in a path of flow of current by the atoms or molecules of the conductor.
Factors on which resistance of a conductor depends are:
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- Length
- Area of cross section
2. Rheostat is used to change the resistance without changing the voltage source in an electric circuit.
3.
Given :
We know that,
The intensity of an electromagnetic wave increases with the field strength.
Answer:
Explanation:
First, we can find the mass of the object in air
Since W = mg
m = W/g = (8.9)/(9.8) = 0.908 kg
Then, by Archimedes principle, we can find its volume. The volume is found by the weight of the water displaced by the formula
W = Vρg
The Weight is the difference in scale readings. The density of water is 1000 kg/m3
(8.9- 7.8) = V(1000)(9.8)
Thus V = 1 X 10-4 m3
Then, since density is mass / volume
ρ = 0.908/1 X 10-4
ρ = 8254 kg/m3 which is 8 X 103 kg/m3
The density of gold is 19.3 X 103 kg/m3
Since those densities are not the same, the crown is either hollow or not pure gold
The correct answer is B) Ultraviolet light source. Hope this helps.
