EWRB Theory Exam Prep Questions With Guaranteed Pass Solutions.
7 views 0 purchase
Course
Electrical Theory
Institution
Electrical Theory
What is the minimum value of the permitted test result for the insulation resistance test of a three-phase, 400V, mains cable? - Answer 1MΩ
When carrying out testing on a low voltage electrical installation, which document details the tests and checks required to be carried out? - Answer ...
EWRB Theory Exam Prep Questions
With Guaranteed Pass Solutions.
What is the minimum value of the permitted test result for the insulation resistance test of a three-
phase, 400V, mains cable? - Answer 1MΩ
When carrying out testing on a low voltage electrical installation, which document details the tests and
checks required to be carried out? - Answer AS/NZS 3000
What is the minimum or maximum test result value you would consider acceptable for an Earth
Continuity test? - Answer 1Ω or less
State TWO types of electrical protection provided by a RCBO. - Answer ANY TWO:
- Earth Leakage
- Overload
- Short Circuit
If the voltage and current are known, what TWO other factors are required to calculate the power
consumed by a three-phase motor? - Answer √3 & Power Factor
What type of single-phase motor can be reversed by reversing the connections to the run winding? -
Answer ANY ONE:
- Split-Phase Motor
- Capacitor Start Motor
- Cap-Start, Cap-Run Motor
What type of single-phase motor can be reversed by reversing the connections to the armature brushes?
- Answer ANY ONE:
- Universal Motor
- Series Motor
, State ONE reason why the metal frame of a Class 1 electrical appliance is earthed. - Answer ANY ONE:
- To ensure the operation of a protective device under fault conditions.
- To keep the frame of the appliance at earth potential under fault conditions.
State TWO factors that determine the severity of electric shock upon the human body. - Answer ANY
TWO:
- Voltage Applied
- Shock Current Level
- Contact Duration
- Skin Dryness
- Current Path
You have carried out a test on a low voltage final subcircuit in an electrical installation, the result value
was 20MΩ. What type of test has been carried out? - Answer Insulation Resistance Test
State the main reason why interlocks are used in a star/delta starter. - Answer To prevent the star and
delta contractors closing simultaneously - and causing a short circuit.
Calculate the power factor of a small three-phase printing factory with mainly motor loading. Metering
instruments have recorded the following:
Power = 30000W
Voltage = 406V
Current = 57A per phase - Answer 0.748
pf = P/V×I×√3
Define the term CUT OFF TIME as it refers to HRC fuses. - Answer ANY ONE:
- Pre-arcing Time: Time taken to melt the fuse elements.
- Arcing Time: The time taken between the initiation of the arc, and the arc extinguishing.
- Cut Off Current: The fault current that will cause the fuse to blow.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller TestSolver9. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.49. You're not tied to anything after your purchase.
