Final answer:
The need for an IoT network is to ensure efficient connectivity and data exchange with minimal energy use, thus option 1 ('To use low power energy') is correct. IoT aims to minimize power consumption and reduce energy loss during transmission, rather than transmitting over long distances or using high power energy.
Step-by-step explanation:
The need for an Internet of Things (IoT) network is to provide connectivity among various devices that can monitor, control, and exchange data with minimal human intervention. One key requirement for an IoT network is to use low power energy to ensure efficiency and extended life for devices that may be battery operated or difficult to recharge frequently.
The IoT network does not aim to use high power energy; rather, it aims to be as energy-efficient as possible (reduce energy loss during transmission). In the context of power transmission, it is essential to transmit with high voltages and low currents to reduce power loss; this is because power loss is directly related to the square of the current (Plost = Itransmitted2 Rwire). By reducing the current, power losses over long distances, such as the kilometers-long lines from power companies, can be minimized. Finally, IoT networks often don't need the signal to be sent very far from the transmitter, which allows for even more power efficiency.
Therefore, the correct answer to the question 'What is the need of an IoT network?' is 'To use low power energy'. Consequently, options 1 ('To use low power energy') and 4 ('a and b are correct') could be considered correct if 'b' were interpreted as 'To reduce energy loss during transmission'. However, option 1 is the most precise answer.