plz answer it fast

Solution : 

1. When the resistance of the conductor increases then the current will decrease (option B).
We know that, according to Ohm's law :
I = V/R 
i.e.  I ∝ 1/R 
where, I = current 
V = potential difference 
R = resistance 
The current is inversely proportional to the resistance. Hence, when resistance increases the current decreases 

2. We know that,
I = V/R
when potential difference is doubled and resistance is halved then,
I = 2V/(R/2) 
I = 4 V/R 
Hence, current becomes the four times (option D).

3. Straight line is obtained on drawing the graph of current against potential difference, this proves Ohm's law (option B).

Kindly post the different questions in different thread.