An Automatic Night Light uses a photocell to detect the amount of available light in a room. Under strong light the resistance of the photocell is 1kO but goes up to 100k2 in total darkness. The photocell is put in series with a 4.7kN resistor so as to make a voltage divider when the ends are connected between +5V and GND as shown. As it gets darker in the room, the resistance of the photocell goes up and raises the voltage on the "Sensor Voltage" line. At “dusk", the photocell has a resistance of 10k2. Automatic Night Light 5v Vdd а. What will the range of the sensor voltage be as the photocell +5V goes from 1k2 (bright light) to 100k2 (total darkness)? Photocell Sensor Voltage LM358AD b. Write the equation for VoUT expressed in terms of the op-amp Vout U1A mmarceau 5V inputs and gain. What is the maximum range for VoUT? Reference R4 34.7ka Voltage (V) White LED C. Assuming the light is to come on at "dusk", what must the POTENTIOMETER reference voltage be set to to have the LED come on? SR3 d. If the white LED has a VF of 3.0V @ 10mA, what would be a suitable value for R3?

Q: The book says I should have found 46amps. Is this a misprint?

A: as the given explanation in the previous is correct.

Q: 6. Refer to the graphics appendix. What is the total current from the battery? 23.3 mA 21.85 mA 8.75…

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Q: 1=4 mA E=6 V

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Q: 20. Refer to graphic H. What is the resistance needed to be equivalent to the circuit in the box,…

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Q: which of the following does not increase resistance.

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Q: finding the current to each resistance

A: Assign the voltages at the nodes and the currents in the resistors as shown. Use nodal analysis to…

Q: Convert 2 cm2 to  m2 Convert 100 m3 to cm3

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Q: 4. Solve GOV the currents and find the voltage drop for each resistor. R₁ = 102 R3 57 R5 1522 the…

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Power Measurement

According to Blondel's theorem, the total power is measured with one less number of wattmeters than the number of wires present in the system. So, a single-phase and two-wire system will require one wattmeter and a single-phase and the three-wire system will require two wattmeters, and a three-phase and the three-wire system will also require two wattmeters and a three-phase and the four-wire system will require three wattmeter devices. The wattmeter is a device that measures power using one voltage and one current input as shown in the above figure. Multiple current or voltage input pair cables are used by many power analyzers and digital storage oscilloscopes (DSOs) for measuring watts, in effect within a single instrument acting as multiple wattmeters. It is possible to measure three-phase and four-wire power with one correctly specified power analyzer.