Use Lenz's law to determine the direction of induced current in the situations described by Figure:
$(a)$ $A$ wire of irregular shape turning into a circular shape;
$(b)$ $A$ circular loop being deformed into a narrow straight wire.

(N/A) According to Lenz's law,the direction of the induced emf is such that it opposes the change in magnetic flux that produced it.
$(a)$ As the wire expands to form a circle,the area enclosed by the loop increases. Since the magnetic field is directed into the page (represented by crosses),the magnetic flux through the loop increases. To oppose this increase,the induced current must create a magnetic field directed out of the page. By the right-hand rule,this corresponds to an anticlockwise direction of current,i.e.,along $adcba$.
$(b)$ When the circular loop is deformed into a narrow straight wire,the area enclosed by the loop decreases,leading to a decrease in the magnetic flux through the loop. To oppose this decrease,the induced current must create a magnetic field directed into the page. By the right-hand rule,this corresponds to a clockwise direction of current,i.e.,along $abcda$.