Let's mention 2 examples of a mixture:
1) blood- blood is a mixture of blood plasma and blood cells. Blood is very important to many forms of life, including humans. It's therefore essential to living things!
2) ocean water! it's also a mixture and it covers a great portion of the Earth.
Answer:

Explanation:
From the question we are told that:
Dimension of Wall:

Electric field 
Angle 
Generally the equation for electric Flux is mathematically given by



Answer:
15km/h
Explanation:
Time taken to complete 30km/h=2 hours=15km/h hence the average speed is 15km/h.
Answer: Atoms are electrically neutral because they have equal numbers of protons (positively charged) and electrons (negatively charged). If an atom gains or loses one or more electrons, it becomes an ion.
Answer:
Same
Explanation:
Let R be the resistance of the cell and E be the emf.
Let i be the current in the circuit.
i = E / R ..... (1)
Now emf and resistance be doubled.
so, i' = 2E/2R = E/R
So, i' = i (From equation (1)
Current remains same.