Physics Questions

Thermoplastic materials is a type of plastic material that can be cooled and heated several times without any change in their chemistry or mechanical properties.

Examples of Thermoplastic ::

• polyethylene,
• polypropylene,
• polyvinyl chloride,
• polystyrene,
• polybenzimidazole,
• acrylic,
• nylon and
• teflon

Based on conventionality in deriving energy, energy sources could be classified as

Conventional ::

coal, oil, hydro, nuclear, etc... sources which can be used up or exhaustible.

(and)

Non - conventional ::

solar, wind, tidal, geothermal, biogas, etc... sources which are not exhausted.

Among the given options, Geothermal energy is the alternative energy source among all the choices that are given in the question, that is exhaustible.

without this centripetal force, circular motion is not possible. It acts radially towards the centre and if this force is removed there will be no circular motion but the revolving body will fly off at a tangent.

Black  surfaces are good emitters of heat ( They are also good absorbers of heat). If the black surface is rough too, the emitting will be better. So (b) is the correct answer. Shining surfaces reflect back radiation. So if the black surface is also shining the effectiveness of emitting heat is lessened.

Fathometer is used to measure the depth of the ocean.

Hooke's law states that within the elastic limit, stress developed is directly proportional to the strain produced in a body.Hooke’s law is valid only in the linear part of stress-strain curve. Hence, statement 1 is correct.

1st copper wire: R = pl/A = pl/ πr2

2ndcopper wire: R’ = p’l’/A’ = pl/(4 πr2) = R/4

If joined in parallel, (1/Req) = (1/R) + (1/R’)

= 1/R + 4/R1/Req= 5/R

Req= R/5

All automobiles uses satellite communication channel for their GPS devices.