This set of Video Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Essential Features of Front Projectors”.
1. In rear projector, the screen size is not fixed.
Explanation: The above statement is false. Standard TV sets have 4:3 aspect ratio. HDTV and movies on DVD discs use a wider aspect ratio of 16:9. So, we need to see that the projector supports both 4:3 and 16:9 aspect ratio. In rear projector, the screen size is fixed. It can be made bigger or smaller in a front projection system by shifting the projectors or changing its settings.
2. How is the resolution expressed in a front projector?
a) Number of aspect ratio
b) Number of lines
c) Number of colors
d) Number of pixels
Explanation: Resolution means capacity to produce clear and sharp pictures for any device producing pictures like projectors and televisions. Resolution is expressed by the number of pixels from which the information gets picked up during scanning. It is different from vertical and horizontal scanning.
3. Which annoying effect can be overcome by using interlaced scanning in front projectors?
b) Black level
c) Blanking level
d) Contrast ratio
Explanation: To overcome the annoying effect of flicker, interlaced scanning is used where a vertical scanning rate of 25 frames (50 fields) per second is used in PAL system and 30 frames (60 fields) are used in NTSC system.
4. Which projectors usually have the best black level?
Explanation: DLP (Digital Light Processing) projectors usually have the best black level. Black level is the ability of a projection TV to reproduce colors in their original form. Good black level is important for making dimly lit scenes look good. Reflective, Front and Transmissive projectors black level is not as good as DLP.
5. What is the ideal range of gain while selecting a screen in a front projector?
a) 1.2 to 2
b) 3.2 to 4
c) 4.1 to 4.9
d) 3.6 to 4.5
Explanation: Screen quality is one of the essential features of front projector. While selecting the screen, particular attention should be paid to its gain (the reflectivity). Gain between a range of 1.2 to 2 is good because very high gain limits the viewing angle.
Sanfoundry Global Education & Learning Series – Video Engineering.
To practice all areas of Video Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.