Teaching BPSC बिहार माध्यमिक TGT (9 to 10) शिक्षक भर्ती 4.0 Mock Test General Science Physics Magnetism
The magnetic field produced by a solenoid increases by:
1
changing direction of current
2
placing soft iron core inside it
3
changing direction of solenoid
4
More than one of the above
5
None of the above