GATE CS Application Layer Protocols: DNS, SMTP, HTTP, FTP, Email questions

Which of the following statements is/are true with respect to the interaction of a web browser with a web server using HTTP $1.1$?

Which one of the following protocols may need to broadcast some of its messages?

Consider the resolution of the domain name $\textsf{www.gate.org.in}$ by a $\text{DNS}$ resolver. Assume that no resource records are cached anywhere across the $\text{DNS}$ servers and that iterative query mechanism is used in the resolution. The number of $\text{DNS}$ query-response pairs involved in completely resolving the domain name is …

Assume that you have made a request for a web page through your web browser to a web server. Initially the browser cache is empty. Further, the browser is configured to send $\textsf{HTTP}$ requests in non-persistent mode. The web page contains text and five very small images.The minimum number of $\textsf{TCP}$ connections required to display the web …

Which of the following protocol pairs can be used to send and retrieve e-mails (in that order)?

Which one of the following protocols is NOT used to resolve one form of address to another one?

Which of the following is/are example(s) of stateful application layer protocol? $\textsf{HTTP}$ $\textsf{FTP}$ $\textsf{TCP}$ $\textsf{POP3}$

In one of the pairs of protocols given below , both the protocols can use multiple $\textsf{TCP}$ connections between the same client and the server. Which one is that?

The protocol data unit (PDU) for the application layer in the Internet stack is:

Consider the different activities related to email. $\text{m1}:$ Send an email from mail client to mail server $\text{m2}:$ Download an email from mailbox server to a mail client $\text{m3}:$ Checking email in a web browser Which is the application level protocol used in each activity?

What is the maximum size of data that the application layer can pass on to the TCP layer below?

Which one of the following uses UDP as the transport protocol?