Science !

1. according to the diagram where is the resistor located?
a, b, c, or d

2. according to the diagram where is the switch located?

a, b, c, or d

1. The resistor is located at point D.

A resistor is an element of a circuit that opposes to the flow of current through it: the value of its resistance (R) tells how much the resistor opposes to the flow of current, and the resistance is related to the voltage in the circuit (V) and the current (I) by the Ohm's law:

Resistance is measured in Ohm (), and a resistor is usually represented with a zig-zag line as the one at point D.

2. The switch is located at point B.

A switch is an element of the circuit that can be switched on and off, opening and closing the circuit, therefore allowing or not the flow of current through it. When the switch is open, no current flows; when it is closed, the current can flow through the circuit.

The symbol of a switch is represented at point B.

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.