why is the emf zero , when the maximum number of magnetic field lines of force pass through the coil?

I couldn't understand the meaning of the question

How to get expertise in Class 10 science this year and get preparation for boardexam

AB is a current carrying conductor in the plane of the paper as shown in the figure below. (i) What is the direction of the magnetic field produced by it at point ‘X’? Write the statement of the rule used to find the direction of field lines. (ii) If the polarity of the battery connected to the wire is reversed, how would the direction of the magnetic field be changed? (iii) Point ‘X’ is at a distance r1 and point ‘Y’ is at a distance r2 (r1

formula of c in curies temperature please ansewr i am waiting for the answer

 

For minimum flux the angle between the magnetic field and normal to the surface is

What is the de Broglie wavelength ( in am) associated with an electron subjected to a potential difference of 54 volt