The figure illustrate how B, the flux density inside a sample of unmagnetised ferromagnetic material varies with `B_(0)`, the magnetic flux density in which the sample is kept. For the samle to be suitable for making a permanent magnet

Options

A. `OQ` should be large, `OR` should be small
B. `OQ` and `OR` should both be large
C. `OQ` should be small, `OR` should be large
D. `OQ` and `OR` should both be small

Answer

B

Explanation

In the given figure OQ refers to retentivity while OR refer to coercivity, for permanents both retentivity and coercivity should be high.