Consider the following statements related to d.c.-d.c. converters:
1. The polarity of output voltage and input voltage of a single-ended primary inductance converter is opposite.
2. The polarity of output voltage and input voltage of a Cuk converter is opposite.
3. The polarity of output voltage and input voltage of a buck-boost converter is same.
4. The polarity of output voltage and input voltage of a boost converter is same.
Which of the above statements are correct?
1
1, 2, 3 and 4
2
1, 2 and 3 only
3
1 and 3 only
4
2 and 4 only
5
None of these