What voltage levels are used for binary 0 in RS-232?

Which of the following microcontrollers has 8 interrupt sources?

Which I/O port can be used for the higher address byte with addresses A8-A15?

Which of the following values can be taken in a counter of 8051 microcontroller?

Which of the following is a branch instruction in the instruction set of 8051 microcontroller ?

The TMOD register has inputs 1010 0011. Which of the following timer is functional here in the 8051 microcontroller ?

Which addressing mode in the 8051 microcontroller uses the @ symbol ?

What is the function of Pin No. 20 in the 8051 microcontroller pin configuration?

What does UART stands for, in the serial communication of 8051 microcontroller ?

Which of the following statements about the I/O port pins in an 8051 microcontroller is false?