Nt1310 Unit 6

1. Electron is a negatively charged particle present in an ----------.
(a) Atom
(b) Proton
(c) Neutron
(d) None of the above

2. The formula 2n2 determines the____________ that can be accommodated in any level.
(a) Electrons
(b) Atoms
(c) Neutrons
(c) Protons

3. __________ are used to get a strong magnetic field.
(a) Superconductors
(b) Semiconductors
(c) Magnetic field
(d) None of the above

4. -----------------are used in heating elements, precision instruments, incandescent lamps, and motor starters.

(a) Low Resistivity Materials
(6) Medium Resistivity Materials
(c) High Resistivity Materials
(d) None of the above

5. Mercury as a ________ contact material is a metal liquid.
(a) an Electric
(b) metallic
(c) liquid
(d) gas

6. -------------- is not a Semiconductor.
(a) Silica
(b) Silver
(c) Iron
(d) Aluminum

7.
If a sine wave has frequency of 50 Hz, then the angular frequency is.
(a) 10 n radian/second
(b) 100 n radian/second
(c) 200 n radian/second
(d) 50 n radian/second

8. The reactance offered by a capacitor to alternating current of frequency 50 Hz is 20 Q. If frequency is increased to 100 Hz, then reactance becomes -----------------.
(a) 100 ohms
(b) 20 ohms
(c) 10 ohms
(d) 15 ohms

9. The form factor is the ratio of r.m.s. to ___________.
(a) Peak
(b) average
(c)
medium
(d) none of the above

10. Si02 is the main constituent of -----------.
(a) Glass
(b) Quartz
(c) Corrundum
(d) Neoprene

11. A heater is having 230 V, 10 kW ,the value _________ refers to r.m.s. voltage.
(a) 230 V
(b) 200V
(c) 250V
(d) 100V

12. The resultant is a sinusoid of the same frequency, if two sinusoids of the same frequency but of different amplitudes and phase angles are _________.
(a) Subtracted
(b) added
(c) multiplied
(d) divided