# General Knowledge - Technology

### Exercise :: Technology - Section 1

16.

What frequency range is the High Frequency band?

 A. 100 kHz B. 1 GHz C. 30 to 300 MHz D. 3 to 30 MHz

Explanation:

The HF band is based on frequencies 3 to 30 Mhz. AM radio stations are in the HF band but normally are stated in kilohertz.

17.

The first step to getting output from a laser is to excite an active medium. What is this process called?

 A. Pumping B. Exciting C. Priming D. Raising

Explanation:

A collection of atoms or molecules that can be excited to a higher energy state is called an active medium. Before lasing can occur, the active media is "pumped". The process of raising the atoms in the active media from a lower energy state to a higher state is like pumping water up from a well.

18.

What is the relationship between resistivity r and conductivity s?

 A. R = s2 B. R = s C. R > s D. R = 1/s

Explanation:

No answer description available for this question. Let us discuss.

19.

Which motor is NOT suitable for use as a DC machine?

 A. Permanent magnet motor B. Series motor C. Squirrel cage motor D. Synchronous motor

Explanation:

The squirrel cage motor is the only one without any connection to the armature.

20.

A given signal's second harmonic is twice the given signal's __________ frequency...?

 A. Fourier B. Foundation C. Fundamental D. Field