Which one if you want independent variable meaning that means variable (often denoted by x ) whose variation does not depend on that of another.
Sorry I didn't see this before...
Okay, I see two major problems with this student's experiment:
1) Nitric acid Won't Dissolve in Methane
Nitric acid is what's called a mineral acid. That means it is inorganic (it doesn't contain carbon) and dissolves in water.
Methane is an organic molecule (it contains carbon). It literally cannot dissolve nitric acid. Here's why:
For nitric acid (HNO3) to dissolve into a solvent, that solvent must be polar. It must have a charge to pull the positively charged Hydrogen off of the Oxygen. Methane has no charge, since its carbon and hydrogens have nearly perfect covalent bonds. Thus it cannot dissolve nitric acid. There will be no solution. That leads to the next problem:
2) He's Not actually Measuring a Solution
He's picking up the pH of the pure nitric acid. Since it didn't dissolve, what's left isn't a solution—it's like mixing oil and water. He has groups of methane and groups of nitric acid. Since methane is perfectly neutral (neither acid nor base), the electronic instrument is only picking up the extremely acidic nitric acid. There's no point to what he's doing.
Does that help?
Answer: The electrons flowing through the wire are referred to as a quantity of electricity, and the flow of electricity is referred to as “an electric current.”
Explanation: Hope it Helps have a blessed day
Answer:
Frequency required will be 2421.127 kHz
Explanation:
We have given inductance 
Current in the inductor 
Voltage v = 13 volt
Inductive reactance of the circuit 

We know that


f = 2421.127 kHz