The desirable properties for making permanent magnets are

1.  high retentivity and high coercive force

2.  high retentivity and low coercive force

3.  low retentivity and high coercive force

4.  low retentivity and low coercive force

Electromagnets are made of soft iron because soft iron has

1.  high retentivity and high coercive force

2.  high retentivity and low coercive force

3.  low retentivity and high coercive force

4.  low retentivity and low coercive force

When a ferromagnetic material goes through a hysteresis loop, the magnetic susceptibility:
(a) has a fixed value
(b) may be zero
(c) may be infinity
(d) may be negative
Choose the correct option: 
1. (a), (b), (c)
2. (b), (c), (d)
3. (c), (d), (a)
4. (a), (d), (b)