Answer: The correct statements are ; A and B.
Explanation:
The strength of the magnetic field(B) in an electromagnet can be calculated using formula:

= Relative permeability
N = number of turns
I = Current in the wire of the solenoid
L = length of the solenoid or electromagnetic
As we can see from the formula:


So, by increasing the turns and increasing current flowing through wire one can increase the strength of an electromagnet.
Hence, the correct statements are ; A and B.
Answer: a
Explanation: because an Arrhenius acid is a compound that increases the H + ion concentration in aqueous solution. An Arrhenius base is a compound that increases the OH − ion concentration in aqueous solution.
I have heard they can use hair is stocking or nets to absorb the oil out of the water
To answer this item, we assume that oxygen behaves ideally such that it is able to fulfill the following equation,
PV = nRT
If we are to retain constant the variable n and V.
The percent yield can therefore be solved through the following calculation,
n = (10.5 L)/(22.4 L) x 100%
Simplifying,
n = 46.875%
Answer: 48.87%