Typically the micrometer reading giving the deep (and very shan ) null could be 10 mm. (it would normally be expressed to several significant figures, e.g 10.02 mm.)
Other nulls will be found. In a typical experiment the next two null occured at 14.86 mm (less deep) and 13.7 to 14 mm (quite deep broadly spread over this 0.3 mm- long region). Other nulls may be found, becoming increasingly erratic.
At these results show, selection of the correct null is essential. The micrometer should be screwed fully in to start with, then unscrew carefully until the deepest null is found.
along the guide. There are thus two waves; the original, or"incident" wave, and the "reflected" wave travelling in the opposite direction. There are places where their electric fields will be in phase, and other places where they will tend to cancel each other.
Calculate the distance between the two null positions, which is That is; half the wavelength in the waveguide.
A microwave signal is a short-wavelength electromagnetic signal like a radio wave, characterised by a frequency and a wavelength. it can be generated (at low power) by an FET oscillator,guided by a waveguide,and detected by a suitable diode.
A Cavity will resonate at a frequency determined by its physical dimensions. Such a cavity can be used in resonant circuits and filters, much in the same way as an LC circuit is used at lower frequencies. There are many modes of resonance possible in a cavity but the one with the lowest resonant frequency usually gives the deepest null and is most simply related to the cavity dimensions.
An absorption frequency meter is an application of a resonant cavity, loosely coupled to the transmission path,which absorbs r.f. energy when the frequency of the signal is matched by one of the cavity"s resonances. Such a component could be calibrated for measurement of frequency.
The wavelength of the signal in the guide can be measured by sliding a detector probe along a slot in the guide. This component is commonly called a "slotted line