1. If lower voltage is given to the primary and higher voltage is taken from the secondary of a transformer, it is called
a) step up
b) step down
c) current transformer
d) voltage stabilizer
ans. a
2. If the input voltage is 100 V and output voltage is 200 V, which side of the transformer winding's will be primary
a) 200 V side
b) 100 V side
c) Winding with more turns
d) Winding with less turns.
ans. d
3. Shell-type transformer is commonly used because
a) it has more magnetic flux leakage
b) it has less magnetic flux leakage
c) it has two magnetic paths
d) both b and c are correct
ans. d
4. The transformer is commonly used because
a) it has high efficiency
b) frequency remains constant
c) construction cost per kVA is less as compared to other machines
d) All of these
ans. d
5. The emf induced in the secondary winding depends upon
a) number of turns
b) flux
c) supply frequency
d) all of these
ans. d
6. When the secondary of the transformer is loaded , the flux in the transformer will
a) remain constant
b) directly proportional to secondary current
c) directly proportional to the current drawn by primary winding
d) none of these
ans. a
7. When secondary of the transformer is loaded , the current in the primary side will
a) not be effected
b) increase
c) decrease
d) be the sum of no-load current and excessive current drawn due to secondary current.
ans. d
8. Electric power is transferred from one coil to the other coil in a transformer
a) electrically
b) electromagnetically
c) magnetically
d) physically
ans. c
9. A transformer operates
a) always at unity power factor
b) has its own power factor
c) at a power factor below a particular value
d) at power factor depending on the power factor of the load
ans. d
10. The lamination's are made from
a) silicon sheet steel
b) nickel alloy steel stamping
c) low carbon steel
d) chrome steel sheets
ans. a
a) step up
b) step down
c) current transformer
d) voltage stabilizer
ans. a
2. If the input voltage is 100 V and output voltage is 200 V, which side of the transformer winding's will be primary
a) 200 V side
b) 100 V side
c) Winding with more turns
d) Winding with less turns.
ans. d
3. Shell-type transformer is commonly used because
a) it has more magnetic flux leakage
b) it has less magnetic flux leakage
c) it has two magnetic paths
d) both b and c are correct
ans. d
4. The transformer is commonly used because
a) it has high efficiency
b) frequency remains constant
c) construction cost per kVA is less as compared to other machines
d) All of these
ans. d
5. The emf induced in the secondary winding depends upon
a) number of turns
b) flux
c) supply frequency
d) all of these
ans. d
6. When the secondary of the transformer is loaded , the flux in the transformer will
a) remain constant
b) directly proportional to secondary current
c) directly proportional to the current drawn by primary winding
d) none of these
ans. a
7. When secondary of the transformer is loaded , the current in the primary side will
a) not be effected
b) increase
c) decrease
d) be the sum of no-load current and excessive current drawn due to secondary current.
ans. d
8. Electric power is transferred from one coil to the other coil in a transformer
a) electrically
b) electromagnetically
c) magnetically
d) physically
ans. c
9. A transformer operates
a) always at unity power factor
b) has its own power factor
c) at a power factor below a particular value
d) at power factor depending on the power factor of the load
ans. d
10. The lamination's are made from
a) silicon sheet steel
b) nickel alloy steel stamping
c) low carbon steel
d) chrome steel sheets
ans. a
