Physics Questions

When the piece of iron is lowered into the water, the water level in the bucket increases. And so the pressure at the bottom of bucket also increases. Thus the total thrust at bottom also increases. Therefore the spring balance reading increases. Thus (a) is correct.

The trajectory of the bullet is a parabola

As the inside of the cooker is painted black, heat absorption is more producing heat waves of longer wavelength which cannot escape through glass and hence are trapped inside. Thus the food is cooked.

Sound is a mechanical vibration and needs a medium for propagation. The higher the density of the medium, the faster the sound travels. So, sound cannot travel through vacuum.

As the sound travels faster in solids than liquids and gases, sound travels faster in the glass than Air and water.

"Pressure" is the ratio of mass to area. So, for any given area, the one with more mass pressing on it will experience a higher pressure.

As you go more deeply into the atmosphere OR earth itself, you are putting more and more mass over you. For the same unit area therefore, the pressure, (mass/area) increases.

Hence, the lowest layer will always have the highest pressure i.e, inner core.

The eye can see images separately only if they are exhibited at an interval of more than 1/10 of a second. In the case of a movie, the still pictures come one after the other at less than this minimum interval. So we do not see them separately but only as a continuous moving picture.

Evaporation causing cooling.Here the evaporation is less. Therefore cooling is less.

A barometer is a tool that measures air pressure

A rising barometer indicates increasing air pressure, a falling barometer indicates decreasing air pressure.

In space, there is a nearly complete vacuum, so the air pressure is zero.