Monday, December 24, 2018

Model question paper for Dubai municipality exam for electrical contracting activity

As per the requests of many Engineers, I have prepared a model question paper for the Dubai Municipality exam for Electrical contracting activity.
Please note, this is only a model of questions asked in the exam. If you want to win this exam, you have to study the DEWA regulation document thoroughly.

Model Question Paper:-

Q.1) What is the minimum clear height required for transformer room in basement ?

a)   2.75 
b)   3.0 m
c)   3.7 m
d)   4 m


Q.2) One HP =

a)   0.457 kW
b)   0.600 kW
c)   0.746 kW
d)   1.60 kW

Q.3) What is current rating of an incomer MCCB/Isolator & size of incomer cables required in a distribution board for an electric load of  12kW

a)   40A /16 Sq. mm
b)   63A /25 Sq.mm
c)   80A /35 Sq.mm
d)   100A /35 Sq.mm

Q.4) What should be the height to 13A switched socket provided in kitchen area 

a)   25cm(From the work top)
b)   45cm(From the work top)
c)    60cm(From the work top)
d)   10cm(From the work top)

Q.5) What is the advantage of star connection over delta connection is

a)   Step down voltage 
b)   Step down current
c)   Extra step up current
d)   Extra step up power

Q.6) What is the minimum depth to which an earth electrode must be driven to

a)   3m
b)   4m
c)   5m
d)   6m

Q.7) What is the maximum voltage drop allowed from the point of supply to any point/equipment/appliances connected

a)   1.5% of the nominal voltage of the electric supply
b)   2.5%of the nominal voltage of the electric supply
c)   4.0% of the nominal voltage of the electric supply
d)   5.0%of the nominal voltage of the electric supply

Q.8) What is the maximum earth resistance value allowed for main earth electrode, for each incoming DEWA supply/MDB

a)   10 Ohms
b)   5 Ohms
c)   1 ohm
d)   0.1 Ohm

Q.9) How much voltage is set for 1 minute for High voltage test or Dielectric test on LV panel/MDB conducted in factory as per DEWA regulation

a)   2.5 kV
b)   5 kV
c)   7.5 kV
d)   10 kV

Q.10) The efficiency of a transformer is depended on

a)   Core Loss
b)   Copper Loss
c)   Stray Loss
d)   Dielectric Loss

Q.11) The nominal electric supply voltage from DEWA is

a)   220/380V,50 HZ, 3 phase
b)   230/400V, 50HZ, 3 phase
c)   240/415V,50 HZ, 3 phase
d)   250/440V,50 HZ, 3 phase

Q.12) Metering by means of CT shall be installed where the CB rating at the point of supply is

a)   200 Amp
b)   300 Amp
c)   400 Amp
d)   600 Amp

Q.13) Transformers are rated in

a)   kW
b)   kWh
c)   kV
d)   kVA

Q.14) One lux means

a)   One Lumen/1000 sq. m
b)   One Lumen/100 sq. m
c)   One Lumen/10 sq. m
d)   One Lumen/1 sq.m

Q.15) The glare of lighting can be reduced by:

a)   Using reflectors
b)   Using diffusers in front of reflectors
c)   Increasing the height of lamp
d)   All of above

Q.16) The acceptable power factor of an installation:

a)   Above 0.9 lagging
b)   Below 0.9 lagging
c)   Between 0.8 & 0.9 lagging
d)   Between 0.9 leading and unity

Q.17) Three phase dead short circuit is:

a)   A symmetrical fault
b)   An unsymmetrical fault
c)   All of the above
d)   None of the above

Q.18) What is the maximum chiller load (kW) can be connected to 1500 kVA transformer as per DEWA regulations:

a)   950kW
b)   1200 kW
c)   1500 kW
d)   2000 kW

Q.19) The sum of combined single core cross sectional area of all cables installed on a cable tray shall not exceed how much percentage of interior cross sectional area of that cable tray:

a)   35%
b)   40%
c)   50%
d)   60%

Q.20) In a series circuit the current is:

a)   Constant
b)   Different in different resisters
c)   Proportional to the resistance
d)   Zero always

Q.21) The area of coverage of smoke detector is:

a)    600 sqft
b)   450 sqft
c)   750 sqft
d)   900 sqft

Q.22) What is the recommended lux level in office area work table:

a)   300 lux
b)   500 lux
c)   700 lux
d)   900 lux

Q.23) How many floors in a high rise building shall be supplied by a busbar riser to ensure reliability of power supply interruption during an outage of the respective busbar:

a)   12 floors
b)   8 floors
c)   10 floors
d)   6 floors

Q.24) What is the maximum allowed number of 13A single switched sockets outlets installed in room other than kitchen and controlled by 30/32A circuit breaker in distribution board and connected in a ring circuit:

a)   3 sockets
b)   8 sockets
c)   10 sockets
d)   15 sockets

Q.25) What kind of socket shall be provided for window type air conditioner with cooling capacity upto 18000 BTU/hr:

a)   13 Amp socket
b)   15 Amp socket
c)   20 Amp socket
d)   30 Amp socket

Q.26) What is the recommended rated operating current (mA) value of RCCB for elevators/escalator:

a)   100/300 mA
b)   300/500 mA
c)   100/400 mA
d)   300/1000 mA

Q.27) Minimum cross sectional area of ECC conductor:

a)   16 sq. mm
b)   90 sq. mm
c)   Depends upon the cross sectional area of phase & neutral
d)   Depends upon the earth fault current of supplied load

Q.28) Sub main distribution board must be:

a)   Factory assembled
b)   Site assembled
c)   Factory and site assembled
d)   SMDBs are not acceptable in LV switchgear

Q.29) Which of the below is true about the installation of conduits and trunking:

a)   The cables or wires must be drawn before the installation of conduits
b)   The conduits must be installed before drawing of cables or wires
c)   Trunking is not suitable for the power cables
d)   Conduits are only acceptable as connected to walls or slab

Q.30) What is the minimum area required for 1 x 1000/1500 kVA transformer in basement

a)   21  sq. m(with minimum width of 4.57 mtr)
b)   42 sq. m(with minimum width of 6.1 mtr)
c)   30 sq. m (with minimum width of 3 mtr)
d)   38 sq. m (with minimum width of 5 mtr)

Answer Key:
Q.1 = b  (DEWA regulation 2017; Clause 11.2.6)
Q.2 = c
Q.3 = a
Q.4 = a  (DEWA regulation 2017; Clause 7.4.2)
Q.5 = a
Q.6 = a  (DEWA regulation 2017; Clause 5.2.2)
Q.7 = c  (DEWA regulation 2017; Clause 4.2.3)
Q.8 = c  (DEWA regulation 2017; Clause 5.2.5)
Q.9 = a  (DEWA regulation 2017; Appendix 7 (viii))
Q.10 = a
Q.11 = b  (DEWA regulation 2017; Clause 1.2)
Q.12 = a  (DEWA regulation 2017; Clause 3.3.8)
Q.13 = d
Q.14 = d (DEWA regulation 2017; Section 2, Definitions pg.24)
Q.15 = b
Q.16 = a  (DEWA regulation 2017; Clause 8.1.1)
Q.17 = a
Q.18 = a  (DEWA regulation 2017; Clause 4.7.2)
Q.19 = c  (DEWA regulation 2017; Appendix 12 (3))
Q.20 = a
Q.21 = d
Q.22 = b  (DEWA regulation 2017; Clause 12.2.4(c))
Q.23 = a  (DEWA regulation 2017; Clause 7.3.6)
Q.24 = c  (DEWA regulation 2017; Clause 4.7.1)
Q.25 = b  (DEWA regulation 2017; Clause 4.6.6)
Q.26 = b  (DEWA regulation 2017; Appendix 10)
Q.27 = c  (DEWA regulation 2017; Appendix 9)
Q.28 = a  (DEWA regulation 2017; Clause 4.5.1)
Q.29 = b
Q.30 = a  (DEWA regulation 2017; Clause 11.4.3)

So here I have considered 20 questions directly from DEWA regulation document and other questions are all mostly within the knowledge range of Electrical engineers. You have to score 70% marks to win this exam. So if you follow the DEWA regulations document closely, you can win this exam easily. 

Good luck friends!