An ammeter is connected in series to a battery of voltage V_b and a resistor of unknown resistance R_u (Figure 1) . The ammeter reads a current I_o. Next, a resistor of unknown resistance R_r is connected in series to the ammeter, and the ammeter’s reading drops to I₁. Finally, a second resistor, also of resistance R_r, is connected in series as well. Now the ammeter reads I₂.

If I₁/I₀=4/5, find I₂/I₀.

Express the ratio I₂/I₀ numerically.

I₂/I₀ =

Relevant knowledge:

Light is made up of transverse electrical electromagnetic field oscillations. When we speak of light oscillations, it’s just about electrical field oscillations. The process of polarization involves a way of limiting light oscillations to one plane. This plane is called the vibration plane. The other plane parallel to this plane that contains the direction of the propagation is known as the polarization plane in which the electric field is blocked from oscillation or from oscillating. Intensity of plane polarized light passing through a polarizer is given by the equation I=I₀cos²(θ). Here I₀, I, θ are the incident intensity, transmitted intensity, angle between the plane of vibration of the polarized beam and transmission axis of the polarizer respectively.