push button and keypad

what is the primary function of a push button switch

Connect two contacts to allow current flow

Pushbutton has four pins, how many actual electrical connections does a tactile push-button have?

2

Why are pull-up or pull-down resistors used in button circuits?

To ensure stable input and avoid floating states

What can happen if a push-button is connected without a resistor?

Input may float and give unreliable readings

Which Arduino code keyword enables the internal pull-up resistor?

input pullup

What does a pull-down resistor do in a push-button circuit?

Pulls signal LOW when button is open

What does a pull-down resistor do in a push-button circuit?

Pulls signal LOW when button is open

What value resistor is commonly used as a pull-down resistor?

10k

What issue does debouncing address?

Noisy signals from mechanical buttons

Why is “digitalRead” used in button programs?

To read the state of the button

Which state is interpreted as “pressed” in INPUT_PULLUP mode?

low

Which pin mode requires an external resistor?

input

what is a keypad made of

Matrix of buttons arranged in rows and columns

What happens when a keypad button is pressed?

A row and a column are connected

Which combination corresponds to pressing number 5 on a 4x4 keypad?

Row 2, Column 2

How does Arduino detect a pressed key on the keypad?

It checks for continuity between specific row and column pins

What does the Keypad.h library help with?

Interpreting key presses from matrix keypads

Why must each row and column of the keypad be mapped in the code?

To determine which key was pressed

Which of the following devices most likely contains a matrix keypad?

Microwave oven