1. Resistivity of a material depend on
(A) nature of material.
(B) area of the conductor section.
(C) length of the conductor.
(D) all of the above.
2. Negatively charged particle present in an atom is
3. Which of the following metal have lowest temperature coefficient of resistance?
4. The material preferred for transmitting electrical energy over long distance is
(C) steel reinforced copper.
(D) steel reinforced aluminium.
5. The conductivity of a conductor can be increased by
(A) decreasing its temperature.
(B) increasing its temperature.
(C) decreasing its vibration.
(D) increasing its vibration.
6. Superconductivity is observed for
(A) infrared frequencies.
(B) d.c. and low frequency.
(C) a.c. and high frequency.
(D) frequencies having no effect.
7. Which of the following resistive materials has the lowest temperature co-efficient of resistance ?
8. The coils of D.C. motor starter are wound with wire of
9. Which of the following material has the highest dielectric strength?
(A) Oiled Paper.
10. With the decrease in magnetic intensity the relative permeability of a magnetic material
(C) become zero.
(D) remain the same.
11. Which of the following dielectric material is used in the transformers?
(D) Oiled Paper.
12. Which of the following is a paramagnetic material?
13. Which of the following is a diamagnetic material?
14. Which of the following magnetic material is used to made the permanent magnets?
(B) Soft steel.
(C) Hardened steel.
15. Soldering wires are generally made of
(A) steel-tin alloy.
(D) lead-tin alloy.
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