Electronics and Communication Engineering - Power Electronics
Exercise :: Power Electronics - Section 8
1.
In a 3 phase bridge inverter, the gating signals for the three phases have a phase difference of
Answer: Option A
Explanation:
2.
Assertion (A): The circuit of figure thyristor will conduct for 180° during positive half cycle if it is continuously fired.
Reason (R): A thyristor can conduct only when it is forward biased.
A.
Both A and R are correct and R is correct explanation of A B.
Both A and R correct but R is not correct explanation of A C.
A is correct but R is wrong D.
A is wrong but R is correct
Answer: Option D
Explanation:
3.
The total number of leads in SCR, DIAC and TRIAC respectively are
A.
3, 2, 3 B.
2, 3, 3 C.
3, 3, 2 D.
3, 2, 4
Answer: Option A
Explanation:
4.
A single phase semiconverter is feeding a highly inductive load and has a freewheeling diode across the load. The waveshape of input current is
A.
sinusoidal B.
rectangular C.
sinusoidal or rectangular D.
triangular
Answer: Option B
Explanation:
5.
In the below figure, the load is highly inductive. The firing angle is a for each of the thyristors. The periods of conduction of Th1 and Th2 respectively are
A.
0 to p and p to 2p B.
a to p and p + a to 2p C.
a to p + a and p + p to 2p + a D.
a to p - a and p + a to 2p - a
Answer: Option C
Explanation: