Figure Q4 shows for op-amps each used in a comparator circuit

[armin999]

tttttttttttaaaankkkkkkkkkkkkks

 

[hexreader]

Each LED lights when the + input of the corresponding comparator is a higher voltage than the - input.

That is as much of your homework as I am willing to do for you. I will leave you to do the rest of the thinking needed to provide the full answer.

 

[armin999]

but if u give me full answer better for me because I have submit this and other question tomorrow they are assignment and carry mark (sigh) any way thank u so much

 

[SABorn]

Not 100% sure on this question either. My take on it is...........

With 0 volts on the signal input all leds will be on, as you increase the voltage on the signal input each led will go off 1 by 1 as the voltage gets higher (0 to 5 volt)

A use for it might be to indicate a battery voltage (although dont know of a 5 volt battery) and as the battery got flatter more leds came on.

Another use might be a sensor indicator as long as the sensor varied the voltage between 0 and 5 volts.

Also worth noting it would work in 1 volt steps, at 1 volt all leds on, 2 volt 3 leds, 3 volt 2 leds, 4 volt 1 led, 5 volt no leds.

 

[Electronworks]

Slight correction: when the input is at 0V, NO of the LEDs will be on - the LEDs are pulled low. This is the basis of an analogue to digital converter. You might want to Google 'Flash ADC' or 'Flash Analog to Digital converter' That is all the help I am giving you

 

[colin mac]

but if u give me full answer better for me because I have submit this and other question tomorrow they are assignment and carry mark (sigh) any way thank u so much

What's best for you is reading your notes and making an attempt yourself. Then ask a question if you need to. Not copying what someone writes here and submitting it as your own.