Physics Questions

From the given circuit,

The resistors R1 and R2 are in parallel connection and R3 is in series with R1 & R2

The equivalent resistance of R1 and R2 is

Req = (12 × 4)/(12 + 4) = 3 Ω.

Adding R3 in series with the pair gives

R = Req + 9

R = 3 + 9

R = 12 Ω.

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.

Application of temperature changes in the atmosphere is in adiabatics, or temperature change which are caused by compressing or allowing air to expand.

No work done as there is no external external pressure in free expansion. 

Hence, Work done in a free expansion process is Zero.

Nuclear Force

Wind is the flow of gases on a large scale. On the surface of the Earth, wind consists of the bulk movement of air. The force that generates wind is called as Pressure gradient force.

All of the factors that contribute to global winds are 

1) Uneven warming of the earth by the sun
2) Coriolis Effect
3) Convection Cells