Electrical Engineering Materials

Malleability ✘ Toughness ✘ Softness ✘ None of the above ✔

Nichrome ✘ Constantan ✘ Kanthal ✘ Molybdenum ✔

Increase ✘ Decrease ✘ Remain unchanged ✘ Any of the above ✔

Cast-iron ✘ Graphite ✘ Rubber ✘ Glass ✔

Decreases ✘ Increases ✘ Remains constant ✘ Becomes temperature independent ✔

Where lubrication is difficult or im-possible ✘ Where corrosive chemical action exists ✘ Where high temperature exists ✘ All of the above ✔

Holes can exist in certain semiconductors only ✘ Holes can exist in any material including conductors ✘ Holes may constitute an electric current ✘ Holes can be considered as a net positive charge ✔

Insulators ✘ Conductors ✘ Semiconductors ✘ Superconductors ✔

Inject more charge carriers ✘ Reduce the energy gap ✘ Increase the kinetic energy of valence electrons ✘ All of the above ✔

Intensity ✘ Speed ✘ Frequency ✘ Wave length ✔