T2 Q3
Start buttons in a DOL motor control circuit are wired
in parallel with the existing start button
within a DOL wiring circuit emergency stop N/C contact and a remote stop N/C contact are wired
in series with eachother
Within a DOL wiring circuit the N/C closed auxiliary contact of an overload relay is wired
in series with the control stop button
when immersed in water the magnetic field around a permanent magnet will
remain the same
The RMS of a sine wave is calculated by using
0.707 x peak value
the average of a sinewave can be calculated by which of the following
peak x 0.637
The three phase supply is connected in star in order to
create a neutral point
with regard to magnesium oxide as an insulation material which of the following statements is incorrect
it is resistance to carbon dioxide and moisture from the atmosphere
SWA cable buried directly in soil in agricultural installations shall be buried a minimum depth of
600mm
Cables buried in the ground and are enclosed in ducting having a high resistance to impact, other than concrete should be coloured
red
The phase voltage (Uph) of a 400V three phase DELTA supply is
400V
Fire performance cables that are laid onto cable tray should be
should be clipped to tray using copper or stainless steel clips with brass screws or bolts
the minimum level of protection in a wet location of an agriculture premieres which are housed down such as milking parlors and dairies is
IP44
When comparing the heating effects of an alternating supply that has a maximum current of 7A with that of a DC supply that has a current of 5A it can be said that
both circuits generate the same anount of heat
The peak to peak value of a sinewave can be calculated by which of the following formula
peak x 2
the number of full cycles completed by a 50HZ Ac supply in 1 minute is
3000
which of the following coils would have the strongest magnetic field when a current of 2 anos AC flows through it
a coil with 500 turns
which of the following cannot be displayed by an oscilloscope
RMS voltage value
the property of an electrical circuit that opposes the charge in current flow is
impedence
When a 50Hz AC supply of 230V is connected across the plates of a 400V capacitor that is connected in series with a lamp
the capacitor will charge and discharge in sequence with the frequency and the lamp will stay illuminated
Which of the following denotes Inductanve Reactance
XL and is stated in Ohms
The frequency of a 130V DC supply is
0Hz
The display on a digital volt-meter that is set at AC is the
Root mean squared value of the supply