Showing posts with label Materials and Components. Show all posts
Showing posts with label Materials and Components. Show all posts

Thursday, October 29, 2015

Materials and Components

1.Which capacitor-store higher amount of energy?
Air capacitor Paper capacitor Mica capacitor Plastic film capacitor

2.In paramagnetic materials
permanent magnetic dipoles exist but the interaction between neighbouring dipoles is negligible permanent magnetic dipole do not exist permanent magnetic dipoles exist and the interaction between neighbouring dipoles is very strong permanent magnetic dipole moment may or may not exist

3.The core of a coil has a length of 10 cm. The self inductance is 8 mH. If the core length is doubled, all other quantities remaining the same, the self inductance will be
32 mH 16 mH 8 mH 4 mH

4.Two materials having temperature coefficients of 0.004 and 0.0004 respectively are joined in series. The overall temperature coefficient is likely to be
0.08 0.04 0.001 0.0001

5.The number of valence electrons in pentavalent impurity is
5 4 3 1