Subelement A: RADAR Principles – 10 Key Topics – 10 Exam Questions – 8 Drawings— Topic 10: Circuits-2
Question 8-10A2
Element 8 (RADAR)If more light strikes the photodiode in Fig. 8A5, there will be:
Explanation
Photodiodes are semiconductor devices specifically designed to convert light energy into electrical current. When photons of light strike the depletion region of the photodiode, they impart energy to electrons, creating electron-hole pairs. These charge carriers are then swept across the p-n junction by the diode's internal electric field (or an external reverse bias, if operated in photoconductive mode). This movement of charge constitutes an electric current.
Therefore, if more light strikes the photodiode, more photons are absorbed, generating a greater number of electron-hole pairs and resulting in a larger diode current.
Options A and B are incorrect because they contradict the fundamental operating principle of a photodiode, which is to produce more current in response to increased light. Option D is irrelevant to the effect of light intensity on current; while proper polarity is crucial for operation, the question assumes a functional setup and focuses on the *change* in current due to varying light.
Related Questions
8-10A1 In the circuit shown in Fig. 8A4, U5 pins 1 and 4 are high and both are in the reset state. Assume one clock cycle occurs of Clk A followed by one cycle of Clk B. What are the output states of the two D-type flip flops?8-10A3 In the circuit shown in Fig. 8A6, which of the following is true?8-10A4 What is the correct value of RS in Fig. 8A7, if the voltage across the LED is 1.9 Volts with 5 Volts applied and If max equals 40 milliamps?8-10A5 The block diagram of a typical RADAR system microprocessor is shown in Fig. 8A2. Choose the most correct statement regarding this system.