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.
1. Based on Figure 2, at θ = 380°, V would most likely be closest to which of the following?
Your Answer is
Correct Answer is C
Explanation
Looking at figure 2, it can be seen that 360° is two complete cycles, then 380° is equivalent to 360°+20°, just look at the corresponding ordinate when the abscissa is 20°, it should be 4.4 V< /p>