Physics Questions

So, resistance of Wire 2 is R/4 as radius is half of wire 1, so area would be 4 times of wire 1.

Now for resistance in series. R= R1 + R2.

Therefore, Final R= R + R/4 = 5R/4

Sound intensity or level is measured by a unit called a decibel. An 85 decibel noise level is not a safe standard for the public.

Hence, Acceptable noise level for human ear is less than 85 db.

Cast iron is a group of iron-carbon alloys with a carbon content greater than 2% and is a brittle material.

Its usefulness derives from its relatively low melting temperature.

Electrostatic precipitator is used to control Air pollution. An electrostatic precipitator is a filtration device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit.

Bicycle is a compound machine in the above given options. A compound machine is a machine that is formed by two or more simple machines.

Long sightedness is a common vision condition in which nearby objects are blurry.

In this situation, the person with this condition of the eye where the curvature of the cornea is flat or the axial length of the eyeball is short. When light enters the eye, it does not focus directly on the retina, but focuses beyond the retina. This causes near images to appear out of focus and blurred.

Long sightedness is also called hyperopia, and sometimes presbyopia.

We know that,

Weight W = mg. That is mass times gravitational force.