Note:
From Question number's 21 to 30 rules for Answer marking.
If the Questions have options then you have to answer as follows 
If your answer is option 3 Then fill the OMR sheet as ‘3’
If your answer is options 2&4, Then fill the OMR sheet as ‘24’
if you answer is options 1,3&4 then fill the OMR sheet as ‘134’
And if you answer is options 1,2,3&4 then fill the OMR sheet as‘1234’
If the question is numerical based, then fill the OMR sheet as usual
 

The materials suitable for making electromagnets should have. 
(Choose correct options among the following)
1) high retentivity   2) high coercivity
3) low coercivity    4) low retentivity