If the cross-sectional area of a wire is decreased while all other factors remain the same, how will the resistance change? OA
It will increase
OB.
It will decrease.
OC. It will go to zero.
OD
The cross-sectional area does not affect the resistance.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.

0.93xc=0.93x3x10^8m/s

2.54cm is 1 inch

360seconds i 1 hr