A Metropolitan Area Network (MAN) usually interconnects several Local Area Networks (LANs) using a high-capacity backbone technology. Which one of the following links can be used to interconnect the LANs in the MAN?

Direction: Consider the following statements-
$1.$ Radio waves have frequencies from $300$ GHz to as low as $3$ kHz, and wavelength from $1$mm to several kilometers.
$2.$ Radio waves travel at the speed of light.
Which of the statements given above is/are correct?

Directions: Consider the following statements-
$1.$ Wi-Fi is a networking system and belongs to a class of Wireless Local Area Network (WLAN) devices.
$2.$ Wi-Fi uses the same radio frequencies as Bluetooth but with higher power resulting in a stronger connection.
Which of the statements given above is/are correct?

Direction: Consider the following statements-
$1.$ Wavelength Division Multiple Access is a variant of the Frequency Division Multiple Access.
$2.$ In Wavelength Division Multiple Access, the different data streams are transmitted using the different colors in fiber-optical communication systems.
Which of the statements given above is/are correct?

With reference to ‘Near Field Communication (NFC) Technology’, which of the following statements is/are correct?

1. It is a contactless communication technology that uses electromagnetic radio fields.
2. NFC is designed for use by devices which can be at a distance of even a metre from each other.
3. NFC can use encryption when sending sensitive information.
Select the correct answer using the codes given below.