Worksheets141 S24 B
Total questions: 20
Worksheet time: 2hrs 40mins
Name
Class
Date
1.
What is the function of a step-up transformer in a power station arrangement?
a)
a) It decreases voltage
b)
b) It increases current
c)
c) It increases voltage
d)
d) It decreases current
2.
Why is it advantageous to have smaller current when transmitting electricity over long distances?
a)
a) It reduces losses due to resistance
b)
b) It reduces the voltage
c)
c) It requires thicker cables
d)
d) It increases costs
3.
What is the primary purpose of a step-down distribution transformer near the customer?
a)
a) To increase voltage
b)
b) To decrease current
c)
c) To lower voltage
d)
d) To lower current
4.
What determines the limit of a transformer's rating?
a)
a) The voltage it handles
b)
b) The current it handles
c)
c) The heat generated in the transformer
d)
d) The primary voltage
5.
Transformers are rated in:
a)
a) Watts
b)
b) Amperes
c)
c) Volt-Amps (VA)
d)
d) Ohms
6.
What does the "k" stand for in "kVA" and "M" in "MVA" when rating transformers?
a)
a) Kilo (1,000)
b)
b) Million (1,000,000)
c)
c) Kilowatt
d)
d) Megawatt
7.
What does the VA rating of a transformer indicate?
a)
a) The voltage it can handle
b)
b) The load it can deliver without overheating
c)
c) The current it can handle
d)
d) The primary voltage
8.
The VA rating is the same for which sides of the transformer?
a)
a) Primary and Secondary
b)
b) Primary only
c)
c) Secondary only
d)
d) None of the above
9.
How does a transformer control or limit the possible output current level?
a)
a) By increasing the voltage
b)
b) By reducing the voltage
c)
c) By limiting the heat generated
d)
d) By decreasing the winding size
10.
What is the primary function of a transmission or power transformer?
a)
a) To supply electricity to households
b)
b) To distribute power to industrial premises
c)
c) To transmit power between high-voltage networks
d)
d) To supply power to small appliances
11.
What are the typical ratings for transmission or power transformers?
a)
a) 4 MVA to 30 MVA
b)
b) 16 kVA up to 2500 kVA
c)
c) 60 MVA to 1000 MVA
d)
d) 10 to 50 VA
12.
Which type of transformers are used for supplying larger industrial premises or distribution substations?
a)
a) Transmission transformers
b)
b) Small transformers
c)
c) Distribution transformers
d)
d) Supply transformers
13.
What are the typical ratings for supply transformers?
a)
a) 4 MVA to 30 MVA
b)
b) 16 kVA up to 2500 kVA
c)
c) 60 MVA to 1000 MVA
d)
d) 10 to 50 VA
14.
What is the primary winding voltage range for distribution transformers?
a)
a) 36 kV to 66 kV
b)
b) 3.6 kV to 36 kV
c)
c) 500V
d)
d) 100V
15.
What are small transformers typically used for?
a)
a) Industrial premises
b)
b) Distribution substations
c)
c) Hand-held power supply units
d)
d) High-voltage networks
16.
What is the rating of special transformers used for electronics or low-voltage power supplies?
a)
a) 10 to 50 VA
b)
b) 4 MVA to 30 MVA
c)
c) 60 MVA to 1000 MVA
d)
d) 16 kVA up to 2500 kVA
17.
What is the maximum current a 5kVA transformer can handle with a primary voltage of 500V?
a)
a) 5 A
b)
b) 10 A
c)
c) 50 A
d)
d) 500 A
18.
If the secondary voltage is smaller than the primary voltage, what type of transformer is it?
a)
a) Step-up transformer
b)
b) Step-down transformer
c)
c) Distribution transformer
d)
d) Transmission transformer
19.
What does the transformer's rating control or limit?
a)
a) The primary voltage
b)
b) The output voltage
c)
c) The possible output current level
d)
d) The heat generated
20.
In what units are transformers rated on large transformers other than VA?
a)
a) Kilowatts
b)
b) Amperes
c)
c) Kilovolts
d)
d) Kilovolt-Amperes (kVA)
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