Physics Past Questions and Answers

I. Coherence
II. Same frequency
III. Same wavelength
IV. Same Intensity
Which of the conditions above are necessary to produce interference fringes?

A boy observes a piece of stone at the bottom of a river 6.0m deep. If he looks from the surface of the river, what is the apparent distance of the stone from him? [Refractive Index of Water = 4/3]

A thin wire with heavy weights attached to both ends is hung over a block of ice resting on two supports. If the wire cuts through the ice block while the block remains solid behind the wire, the process is called

Dry
Day 1 - 30°C | Day 2 - 29°C | Day 3 - 25°C
Wet
Day 1 - 22°C | Day 2 - 22°C | Day 3 - 21°C
The reading above are for three consecutive days from a wet and dry bulb hygrometer. It can be concluded that the relative humidity for the three days

One end of a long wire is fixed while a vibrator is attached to the other end. When the vibrator is energized, the types of waves generated in the wire are