Wires and Cables & Resistivity of Wires

Figure shown represents

• GI Conduit (Metallic)

• Cable Tray

• Cable Armouring

• Metallic Trunk

The figure shown represent a

• Single core cable

• Two core cable

• Multi core cable

• Three core cable

The accessory shown is an example of ………………..

• Electrical protection

• Mechanical protection

• Control equipment’s

• Instrument devices

Which one of the following is an example of cables electricalprotection

• Circuit breaker

• Conduit

• Trunk

• Armoring

The name of the device shown is8

• Digital  KWH  Meter

• Fuse

• Service entrance cable

• Main

The device in the picture shown is ...

• Chock coil

• Transformer

• Door lock

• Intercom system

The device shown is a/an ...............

• Three phase main switch

• Single phase ELCB

• Single phase main switch

• Three phase ELCB

According to Bahrain regulations the electric circuits in domesticinstallation are classified as............

• Lighting and power circuits

• Series and parallel circuits

• Ring and redial circuits

• Power and Control circuits

The formula used to calculate the resistance of conductor is givenby

• R = (ρ x A) / L

• R = (ρ) /( A x L )

• R = (ρ x L) / A

• R = L /( A x ρ )

The unit of resistivity of material is ……………..

• Ohm

• Ampere

• Ohm-meter (Ω.m).

• Voltage