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.

We know that,

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

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

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

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.

Wind and solar energy are examples of Renewable energies. 

Renewable energy sources are those which can be naturally replenished. 

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.