Physics Questions

The HF band is based on frequencies 3 to 30 Mhz. AM radio stations are in the HF band but normally are stated in kilohertz.

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.

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.

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

Metamorphism is the change of minerals or geologic texture in pre-existing rocks, without the protolith melting into liquid magma. The change occurs primarily due to heat, pressure, and the introduction of chemically active fluids.

The parent rock must be in solid form. Tons of pressure must be applied for metamorphism to happen. The process must take place underground.

Distance between two Consecutive Crests or two Consecutive Troughs is called Wavelength. But the distance between crest and adjacent trough is half the wavelength.

That is the distance between adjacent crest and trough is called Half the wavelength.

A transformer that increases voltage from primary to secondary (more secondary winding turns than primary winding turns) is called a Step-Up Transformer.

Conversely, a transformer designed to do just the opposite is called a Step-Down Transformer. 

Any object rolls when there is no friction. So, Sliding to Rolling is correct.