Passage I
The LCD screen of a laptop computer emitted plane-polarized light. (A plane-polarized light wave always vibrates along the same axis [for example, up and down]). A special filter was placed in front of the computer screen. Light from the screen passed through the filter and struck a light sensor that was attached to a voltmeter, producing a voltage, V (see Figure 1). As the angular position, θ, of the filter varied, V varied.
A graph of V, in volts, versus θ, in degrees, is shown in Figure 2. Figure 3 shows the relationship between V and the filtered light's intensity, I, in lux.
2. In Figure 2, the change in V was greatest across which of the following intervals of θ ?
Your Answer is
Correct Answer is H
Explanation
Look at figure 2, the change in V is the largest, that is, the vertical coordinate corresponding to the line segment has the largest change, which should be 160°-180°