UGC NET JULY 2018 (Computer Science And Applications Paper-II) (Question 8)

UGC NET JULY 2018 (Computer Science And Applications Paper-II) (Question 8)

Q8. A graphic display system has a frame buffer that is 640 pixels wide, 480 pixels high and 1-bit of color depth. If the access time for each pixel on the average is 200 nanoseconds, then the refresh rate of the frame buffer is approximately :

(1) 16 frames per second                                                  (2) 19 frames per second
(3) 21 frames per second                                                  (4) 23 frames per second

 Answer: (1) 16 frames per second    

Reason : Here 640 pixel wide is width of screen means vertical line on screen and 480 pixels high is means vertical line on screen.
Now                                 width (w) = 640 px             and                   height (h) = 480 px
                                        Total = 640 x 480 = 307200

                                        Color depth = 1-bit/px
                                        Memory required for total pixel = w x h x Color Depth
                                        Memory required for total pixel = 640 x 480 x 1-bit = 307200

                                       1 pixel takes 200 nano second to refresh
                                       To refresh the whole screen = 640 x 480 x 200 ns = 61440000 nano second
                                     
                                       For 1 nano second =   ____1____  screen
                                                                            61440000
                                                                                                                                                        9
                                      Now Convert nano seconds to second we multiply above value with 10
                                                                                                     9
                                      For 1 nano second =   ____1____  x 10  = 16.2760 = 16 (Approximately)
                                                                            61440000

                                      The above solved values is closed to Option (1).