1. DC average current of a half wave rectifier output is

(Where I_{m} is the maxI_{m}um peak current of input

a) 2I_{m}/ᴨ

b) I_{m}/ᴨ

c) I_{m}/2ᴨ

d) 1.414I_{m}/ᴨ

### View Answer

_{m}/ᴨ . Since output of half wave rectifier contains only one half of the input. The average value is the half of the area of one half cycle of sine wave with peak I

_{m}. This is equal to I

_{m}/ᴨ.

2. DC power output of half wave rectifier is equal to

(I_{m} is the peak current and R_{L} is the load resistance)

a) (2I_{m}^{2}/ ᴨ^{2})R_{L}

b) (I_{m}^{2}/2 ᴨ^{2})R_{L}

c) (I_{m}^{2}/ ᴨ^{2})R_{L}

d) (4I_{m}^{2}/ ᴨ^{2})R_{L}

### View Answer

_{m}

^{2}/ ᴨ

^{2})R

_{L}. Since power is VDC * IDC, = I

_{m}/ᴨ

_{x}V

_{m}/ᴨ = V

_{m}I

_{m}/ ᴨ

^{2}We know V

_{m}= I

_{m}R

_{L}. Therefore, power = (I

_{m}

^{2}/ ᴨ

^{2})R

_{L}.

3. Ripple factor of half wave rectifier is

a) 1.414

b) 1.21

c) 1.3

d) 0.48

### View Answer

4. If input frequency is 50Hz then ripple frequency of half wave rectifier will be equal to

a) 100Hz

b) 50Hz

c) 25Hz

d) 500Hz

### View Answer

5. Transformer utilization factor of a half wave rectifier is equal to

a) 0.267

b) 0.287

c) 0.297

d) 0.256

### View Answer

6. If peak voltage on a half wave rectifier circuit is 5V and diode cut-in voltage is 0.7, then peak inverse voltage on diode will be

a) 5.7V

b) 3.6V

c) 4.3V

d) 5V

### View Answer

_{m}um reveres bias voltage that can be appeared across a diode in the circuit. If PIV rating of the diode is less than this value breakdown of diode may occur. For a half wave rectifier PIV of diode is V

_{m}– VD. Therefore, PIV is 5-0.7V.

7. Efficiency of half wave rectifier is

a) 50%

b) 81.2%

c) 40.6%

d) 45.3%

### View Answer

8. In an half wave rectifier, the input sine wave is 200sin100 ᴨt. The average output voltage is

a) 57.456V

b) 60.548V

c) 75.235V

d) 63.694V

### View Answer

_{m}sin wt. Therefore, E

_{m}=200 Hence output voltage is E

_{m}/ ᴨ. That is 200/ ᴨ.

9. In an half wave rectifier, the input sine wave is 200sin200 ᴨt. If load resistance is of 1k then average DC power output of half wave rectifier is

a) 3.25W

b) 4.05W

c) 5.02W

d) 6.25W

### View Answer

_{m}sin wt. On comparing E

_{m}= 200 Power = E

_{m}

^{2}/ ᴨ

^{2}R

_{L}= 200/ ᴨ

^{2}x 1000.

10. In an half wave rectifier, the input sine wave is 250sin100 ᴨt. The output ripple frequency of rectifier will be

a) 100Hz

b) 200Hz

c) 50Hz

d) 25Hz

### View Answer

_{m}sin wt. On comparing equation w = 100 ᴨ rad/s We know w=2 ᴨ

_{x}frequency. Therefore, frequency = 50 Hz. Ripple frequency and input frequency are the same.