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Question #43583
The Question
In a Young's Double Slit Experiment (YDSE), two identical slits emit coherent light of intensity and optical angular frequency . An electro-optic modulator is placed in front of one of the slits, introducing a time-varying phase shift , where is a positive constant in and is the applied voltage. The voltage is supplied by an ideal circuit (inductor , capacitor ). At , the capacitor is fully charged to a voltage and the current is zero. Assume the oscillation frequency is much smaller than . Given the integral identity , where is the zeroth-order Bessel function of the first kind, what is the time-averaged intensity at the central point on the screen (where the geometrical path difference is zero) over one complete period of the oscillation?
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Intuition_Breaker
Train your brain to resist "obvious" answers that are designed to deceive your intuition.
Concepts Behind This Question
Intensity Distribution in YDSE|L-C Circuit Analogy
Why This Question Is Tricky
Common Mistakes
This question tests the transition from static interference models to dynamic, time-averaged intensity distributions.
Students commonly fall into the trap of averaging the phase shift first () and substituting it into the static formula to get , or they incorrectly use the RMS or maximum voltage directly in the static equation.
The lethal collision occurs when they fail to recognize that the interference term is a non-linear function of the oscillating charge.
Correct physical analysis requires applying the time-average integral directly to the instantaneous intensity function, which maps the sinusoidal LC circuit discharge to a Bessel function dependency for the optical intensity.
Quick Facts About This Question
Question Information
| Subject | Physics |
| Chapter | Wave Optics - Class 12 |
| Concept | Intensity Distribution in YDSE |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |