A: That refers to a resistor pull up that is not sufficient to do the job that is to pull up. It also means is greater in value that it should be

A "pull-up" resistor is a resistor used to to perform a specific electronic function - it is not a different type of resistor. A very small current flows through a pull-up resistor so it does not need to be high wattage (1/8 watt is generally fine). The value of a pull-up resistor depends on the resistance of the sensor. If it is simply on or off (no resistance) then a typical pull-up resistor might be 10k ohms.

pull up resistor is a one of the dubakur resister

A pull-up resistor is used to "pull-up" a signal to prevent it from floating or creating an undefined state. Typically a digital input might be looking for a ground or low state to indicate a state. The pull-up resistor is attached to the signal line and to a level which will "pull" the line to a high level in the absense of a low signal. The effect is to provide a reliable hi or lo to an input. The pull up may located close to an input or directly at an output to effect the results. Some eletronic devices have the pull-up devices internally installed.

A strong pullup means using small value resistor for pull up whereas a weak pullup means using high value resistor for pulling the signal to Vcc. A strong pullup reduces the RC time constant.

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