Answer:

Explanation:
As per Ampere's law the magnetic field at the surface of the wire is given as

here we have

so we will have

now again we use same value of current but wire with double the diameter
so the magnetic field at the surface is given as

so we have

Answer:
always same
Explanation:
velocity and speed are same upto some extend but velocity is vector while speed is scalar quantity
Answer:
D. 4Al + 3O2 → 2Al2O3
Explanation:
Chemical reactions involves the chemical combination of two or more substances called REACTANTS to yield other substances called PRODUCTS. However, in accordance with the LAW OF CONSERVATION OF MASS, the amount of reactants must be equal to that of the products.
To accomplish this, the reaction must be BALANCED. A balanced equation is an equation in which the number of atoms of each element in the reactant side equals the number of atoms in the product side. In this reaction involving Aluminum and Oxygen to give Aluminum oxide as follows:
Al + 02 → Al2O3
A coefficient is used to balance the number of atoms on both sides of the equation as follows:
4Al + 3O2 → 2Al2O3
Answer:
Mumbai
Explanation:
Because Mumbai is a coastal city
due to high humidity,vigorous rusting damages all the iron structures
∴ rusting is a major problem in Mumbai
Answer: The right Answer is Velocity has both speed and direction.
Explanation:
i took the test