V=IR (voltage equals current<span> times </span>resistance<span>). So </span>if<span> the voltage </span>increases<span>, then the </span>current increases<span> provided that the </span>resistance remains constant<span>.</span>
I remember c/d. That's not a problem. But if you want 'c', you'll have to give me 'd'.
Answer:
a) 
b) 
Explanation:
Given:
height of water in one arm of the u-tube, 
a)
Gauge pressure at the water-mercury interface,:
we've the density of the water 
b)
Now the same pressure is balanced by the mercury column in the other arm of the tube:
<u>Now the difference in the column is :</u>
Pour the entire components into water.
First the iron filings can be separated using a magnet as iron is a magnetic element.
By pouring the mixture into water, it allows the salt to dissolve in the water, while the sand will not.
Next we can run this solution through a filtration device to separate the sand from the water.
Now all that's left is to let the water evaporate so that the salt will be exposed that dissolved into the water.
