29. A resistance having rating 10 ohms, 10 W is likely to be a
(a) metallic resistor
(b) carbon resistor
(c) wire wound resistor
(d) variable resistor
Ans: c
30. Which one of the following does not have negative temperature co-efficient ?
(a) Aluminium
(b) Paper
(c) Rubber
(d) Mica
Ans: a
31. Varistors are
(a) insulators
(6) non-linear resistors
(c) carbon resistors
(d) resistors with zero temperature coefficient
Ans: b
32. Insulating materials have the function of
(a) preventing a short circuit between conducting wires
(b) preventing an open circuit between the voltage source and the load
(c) conducting very large currents
(d) storing very high currents
Ans: b
33. The rating of a fuse wire is always expressed in
(a) ampere-hours
(b) ampere-volts
(c) kWh
(d) amperes
Ans: d
34. The minimum charge on an ion is
(a) equal to the atomic number of the atom
(b) equal to the charge of an electron
(c) equal to the charge of the number of electrons in an atom (#) zero
Ans: b