UGC NET Questions (Paper – 1)

For a fixed distance, speed and time are inversely proportional, meaning that as speed increases, the time required decreases. When the train’s speed rises from 60 km/h to 80 km/h, it covers the same distance in less time. This relationship is fundamental in time and distance problems. Therefore, the time taken to travel the same distance will decrease.

Option A:
An increase in time would occur only if the speed decreased, not when it increased. Because speed is the rate at which distance is covered, moving faster cannot logically result in taking more time for the same distance. Thus, "increase" contradicts the basic formula time = distance ÷ speed.

Option B:
Decrease is correct because when speed rises while distance remains constant, the denominator in the time formula increases, making the overall time smaller. For example, travelling 160 km at 60 km/h takes about 2 hours 40 minutes, whereas at 80 km/h it takes only 2 hours. This clearly shows a reduction in time, validating option B.

Option C:
If time remained the same, it would imply that changing speed has no effect on duration, which violates the fundamental relationship between distance, speed and time. Since the distance is fixed, a change in speed must affect time. Therefore, this option is not logically possible.

Option D:
Time becoming double would happen only if the speed were halved for the same distance. Here, the speed is increased, not decreased, so the time cannot become double. This directly contradicts the inverse proportional relationship between speed and time.