21. The relative permeability of a ferromagnetic material is A. Less than one B. More than one C. More than 10 D. More than 100 or 1000 Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
22. Energy stored by a coil is doubled when its current is increased by percent. A. 25 B. 50.14 C. 41.4 D. 100 Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
23. Hard steel is suitable for making permanent magnets because A. It has good residual magnetism B. Its hysteresis loop has large area C. Its mechanical strength is high D. Its mechanical strength is low Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
24. The unit of reluctance is A. $$\frac{{{\text{Meter}}}}{{{\text{Henry}}}}$$ B. $$\frac{{{\text{Henry}}}}{{{\text{Meter}}}}$$ C. $${\text{Henry}}$$ D. $$\frac{1}{{{\text{Henry}}}}$$ Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
25. Hysteresis loss least depends on A. Volume of material B. Frequency C. Steinmetz’s coefficient of material D. Ambient temperature Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
26. The rate of rise of current through an inductive coil is maximum A. At 63.2% of its maximum steady value B. At the start of the current flow C. After one time constant D. Near the final maximum value of current Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B No explanation is given for this question Let's Discuss on Board
27. The property of a material which opposes the creation of magnetic flux in it is known as A. Reluctivity B. Magneto-motive force C. Permeance D. Reluctance Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
28. Conductivity is analogous to A. Retentivity B. Resistivity C. Permeability D. Inductance Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board