TRANSFORMERS MCQs SET 21

TRANSFORMERS MCQs SET 21

1. The output transformers are also named as _________
a) Audio transformers
b) Power transformers
c) Industrial transformers
d) Electric transformers
 
Answer: a

2. Which of the following is the major requirement for the transformers used for electronic purposes?
a) Perfect DC isolation
b) Maximum efficiency
c) Constant amplitude voltage gain
d) Perfect DC isolation , maximum efficiency and constant voltage gain
 
Answer: c

3. Why frequency scale is logarithmic?
a) Frequency range is very small for these transformers
b) Frequency range is very large for these transformers
c) Frequency used is negligible
d) Can’t say
 
Answer: b

4. When series leakage inductances are ignored then the region is called as _____________
a) Low-frequency region
b) High-frequency region
c) Mid-frequency region
d) Ultra high-frequency region
 
Answer: c
 
5. What is the gain of the transformer in mid-band region?
a) [N2/N1] [RL ‘/(R+RL’)].
b) [N2/N1] [RL ‘/(R+RL’+jωL)].
c) AH=A0/ [1+(ω/ ωH)2]1/2
d) AL=A0/ [1+(ω/ ωL)2]1/2
 
Answer: a

6. When series leakage inductances are not ignored but shunt inductance is an effective open circuit then the region is called as _____________
a) Low-frequency region
b) High-frequency region
c) Mid-frequency region
d) Ultra high-frequency region
 
Answer: b

7. What is the gain of the transformer in high-frequency region?
a) [N2/N1] [RL ‘/(R+RL’)].
b) [N2/N1] [RL ‘/(R+RL’+jωL)].
c) AH=A0/ [1+(ω/ ωH)2].
d) AL=A0/ [1+(ω/ ωL)2]1/2
 
Answer: b

8. When series leakage inductances are not ignored but shunt inductances are considered in parallel then the region is called as _____________
a) low-frequency region
b) high-frequency region
c) mid-frequency region
d) ultra high-frequency region
 

Answer: a

9. What is the gain of the transformer in low-frequency region?
a) [N2/N1] [RL ‘/(R+RL’)].
b) [N2/N1] [RL ‘/(R+RL’+jωL)].
c) AH=A0/ [1+(ω/ ωH)2].
d) AL=A0/ [1+(ω/ ωL)2]1/2

Answer: d

10. Relative voltage ratio curve for an output transformer is _______________
a) Circular
b) Straight line
c) Bell shaped
d) Irregular curve
 

Answer: c
 
11. Phase angle characteristic of an output transformer is ____________
a) Curve increasing towards high-frequency region
b) Curve increasing towards low-frequency region
c) Curve increasing towards mid-frequency region then decreasing
d) Can’t define
 

Answer: a