Question Description
Directions: Answer the given question based on the following passage.Our digital world depends on the interconnectivity between wireless devices, often battery-free with no direct power supply. Such devices include wireless passive sensors, designed to receive and respond to signals from the environment. These devices can be powered by electromagnetic waves, provided their antenna can efficiently convert waves to energy. When Alexander Graham Bell made the first-ever phone call in 1876, calling his assistant to meet him, the connectivity of todays world would have been well beyond his wildest dreams. Perhaps even in the late 1980s and early 1990s, when the internet as we know it started to emerge, the digital world we have since built would have been unimaginable. Today, we dont just use technology to communicate with each other: we are also finding ways to make devices communicate between themselves to allow us to control our environments. The Internet of Things, as it is now called, is the combination of the immense web of sensors, devices, apps, and other technology that are connected and sharing information between them.To control our world, however, we need to be able to interconnect many devices which, for ease of installation and pleasing design, are usually wireless, including no power supply cables. For environmental reasons, it is also beneficial that these devices are battery-free. Battery-free devices can instead be powered by the electromagnetic waves they receive from the powered devices they are connected to. With the right equipment, the electromagnetic waves sent by the Wi-Fi router could be enough to supply the energy needed to power the motion sensor. Devices whose function is to detect and respond to physical signals from the surrounding environment are called passive sensors. The ability of a passive sensor to harvest energy from the environment depends heavily on the ability of its antenna – which receives electromagnetic waves – to efficiently turn waves into electricity that can power it. As such, a crucial part of improving this remote powering technology involves making the rectifier (the part of the antenna responsible for converting waves to power) work as efficiently as possible.The rectifier performance can be measured in terms of its voltage conversion efficiency, or its power conversion efficiency, where voltage refers to an electrical potential, and power here refers to the rate at which electrical energy is transferred through an electrical circuit. However, these two quantities are closely interlinked in complex ways, to such an extent that optimising one of these parameters is often done at the expense of the other, and it is not possible to optimise both parameters simultaneously. Dominik Mair and his colleagues at the University of Innsbruck in Austria, have shown in a recent publication that using either voltage or power conversion efficiency as measures of rectifier performance is not feasible. Instead, the team demonstrated that the concept of a mean conversion efficiency (the average of the voltage and power conversion efficiencies) allows optimisation algorithms to find optimum rectifier circuit designs much quicker. Not only that, but the resulting designs also show superior overall performance when compared to previous ones, even with very low power from incoming waves. The growing demand for intelligent devices that are interconnected with each other, allowing us to control our environment, is pushing the development of wireless, battery-free sensors which can gather information and even make decisions or control actuators.Q.Why does the author consider that it would have been impossible to imagine a digital world even in the late 20th century?a)There was no knowledge of characteristics like voltage and power efficiency measures during the late 20th century.b)The technology of 1980s and 1990s was incapable to cater to the dynamic idea of Internet of Things (IoT).c)It was difficult to imagine the compounding growth that technology and internet would foster over the coming periods.d)Technology was believed to be the preserve of a few fortunate sections possessing digital know-how and resources to access.Correct answer is option 'C'. Can you explain this answer? for CAT 2024 is part of CAT preparation. The Question and answers have been prepared according to the CAT exam syllabus. Information about Directions: Answer the given question based on the following passage.Our digital world depends on the interconnectivity between wireless devices, often battery-free with no direct power supply. Such devices include wireless passive sensors, designed to receive and respond to signals from the environment. These devices can be powered by electromagnetic waves, provided their antenna can efficiently convert waves to energy. When Alexander Graham Bell made the first-ever phone call in 1876, calling his assistant to meet him, the connectivity of todays world would have been well beyond his wildest dreams. Perhaps even in the late 1980s and early 1990s, when the internet as we know it started to emerge, the digital world we have since built would have been unimaginable. Today, we dont just use technology to communicate with each other: we are also finding ways to make devices communicate between themselves to allow us to control our environments. The Internet of Things, as it is now called, is the combination of the immense web of sensors, devices, apps, and other technology that are connected and sharing information between them.To control our world, however, we need to be able to interconnect many devices which, for ease of installation and pleasing design, are usually wireless, including no power supply cables. For environmental reasons, it is also beneficial that these devices are battery-free. Battery-free devices can instead be powered by the electromagnetic waves they receive from the powered devices they are connected to. With the right equipment, the electromagnetic waves sent by the Wi-Fi router could be enough to supply the energy needed to power the motion sensor. Devices whose function is to detect and respond to physical signals from the surrounding environment are called passive sensors. The ability of a passive sensor to harvest energy from the environment depends heavily on the ability of its antenna – which receives electromagnetic waves – to efficiently turn waves into electricity that can power it. As such, a crucial part of improving this remote powering technology involves making the rectifier (the part of the antenna responsible for converting waves to power) work as efficiently as possible.The rectifier performance can be measured in terms of its voltage conversion efficiency, or its power conversion efficiency, where voltage refers to an electrical potential, and power here refers to the rate at which electrical energy is transferred through an electrical circuit. However, these two quantities are closely interlinked in complex ways, to such an extent that optimising one of these parameters is often done at the expense of the other, and it is not possible to optimise both parameters simultaneously. Dominik Mair and his colleagues at the University of Innsbruck in Austria, have shown in a recent publication that using either voltage or power conversion efficiency as measures of rectifier performance is not feasible. Instead, the team demonstrated that the concept of a mean conversion efficiency (the average of the voltage and power conversion efficiencies) allows optimisation algorithms to find optimum rectifier circuit designs much quicker. Not only that, but the resulting designs also show superior overall performance when compared to previous ones, even with very low power from incoming waves. The growing demand for intelligent devices that are interconnected with each other, allowing us to control our environment, is pushing the development of wireless, battery-free sensors which can gather information and even make decisions or control actuators.Q.Why does the author consider that it would have been impossible to imagine a digital world even in the late 20th century?a)There was no knowledge of characteristics like voltage and power efficiency measures during the late 20th century.b)The technology of 1980s and 1990s was incapable to cater to the dynamic idea of Internet of Things (IoT).c)It was difficult to imagine the compounding growth that technology and internet would foster over the coming periods.d)Technology was believed to be the preserve of a few fortunate sections possessing digital know-how and resources to access.Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for CAT 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Directions: Answer the given question based on the following passage.Our digital world depends on the interconnectivity between wireless devices, often battery-free with no direct power supply. Such devices include wireless passive sensors, designed to receive and respond to signals from the environment. These devices can be powered by electromagnetic waves, provided their antenna can efficiently convert waves to energy. When Alexander Graham Bell made the first-ever phone call in 1876, calling his assistant to meet him, the connectivity of todays world would have been well beyond his wildest dreams. Perhaps even in the late 1980s and early 1990s, when the internet as we know it started to emerge, the digital world we have since built would have been unimaginable. Today, we dont just use technology to communicate with each other: we are also finding ways to make devices communicate between themselves to allow us to control our environments. The Internet of Things, as it is now called, is the combination of the immense web of sensors, devices, apps, and other technology that are connected and sharing information between them.To control our world, however, we need to be able to interconnect many devices which, for ease of installation and pleasing design, are usually wireless, including no power supply cables. For environmental reasons, it is also beneficial that these devices are battery-free. Battery-free devices can instead be powered by the electromagnetic waves they receive from the powered devices they are connected to. With the right equipment, the electromagnetic waves sent by the Wi-Fi router could be enough to supply the energy needed to power the motion sensor. Devices whose function is to detect and respond to physical signals from the surrounding environment are called passive sensors. The ability of a passive sensor to harvest energy from the environment depends heavily on the ability of its antenna – which receives electromagnetic waves – to efficiently turn waves into electricity that can power it. As such, a crucial part of improving this remote powering technology involves making the rectifier (the part of the antenna responsible for converting waves to power) work as efficiently as possible.The rectifier performance can be measured in terms of its voltage conversion efficiency, or its power conversion efficiency, where voltage refers to an electrical potential, and power here refers to the rate at which electrical energy is transferred through an electrical circuit. However, these two quantities are closely interlinked in complex ways, to such an extent that optimising one of these parameters is often done at the expense of the other, and it is not possible to optimise both parameters simultaneously. Dominik Mair and his colleagues at the University of Innsbruck in Austria, have shown in a recent publication that using either voltage or power conversion efficiency as measures of rectifier performance is not feasible. Instead, the team demonstrated that the concept of a mean conversion efficiency (the average of the voltage and power conversion efficiencies) allows optimisation algorithms to find optimum rectifier circuit designs much quicker. Not only that, but the resulting designs also show superior overall performance when compared to previous ones, even with very low power from incoming waves. The growing demand for intelligent devices that are interconnected with each other, allowing us to control our environment, is pushing the development of wireless, battery-free sensors which can gather information and even make decisions or control actuators.Q.Why does the author consider that it would have been impossible to imagine a digital world even in the late 20th century?a)There was no knowledge of characteristics like voltage and power efficiency measures during the late 20th century.b)The technology of 1980s and 1990s was incapable to cater to the dynamic idea of Internet of Things (IoT).c)It was difficult to imagine the compounding growth that technology and internet would foster over the coming periods.d)Technology was believed to be the preserve of a few fortunate sections possessing digital know-how and resources to access.Correct answer is option 'C'. Can you explain this answer?.

Solutions for Directions: Answer the given question based on the following passage.Our digital world depends on the interconnectivity between wireless devices, often battery-free with no direct power supply. Such devices include wireless passive sensors, designed to receive and respond to signals from the environment. These devices can be powered by electromagnetic waves, provided their antenna can efficiently convert waves to energy. When Alexander Graham Bell made the first-ever phone call in 1876, calling his assistant to meet him, the connectivity of todays world would have been well beyond his wildest dreams. Perhaps even in the late 1980s and early 1990s, when the internet as we know it started to emerge, the digital world we have since built would have been unimaginable. Today, we dont just use technology to communicate with each other: we are also finding ways to make devices communicate between themselves to allow us to control our environments. The Internet of Things, as it is now called, is the combination of the immense web of sensors, devices, apps, and other technology that are connected and sharing information between them.To control our world, however, we need to be able to interconnect many devices which, for ease of installation and pleasing design, are usually wireless, including no power supply cables. For environmental reasons, it is also beneficial that these devices are battery-free. Battery-free devices can instead be powered by the electromagnetic waves they receive from the powered devices they are connected to. With the right equipment, the electromagnetic waves sent by the Wi-Fi router could be enough to supply the energy needed to power the motion sensor. Devices whose function is to detect and respond to physical signals from the surrounding environment are called passive sensors. The ability of a passive sensor to harvest energy from the environment depends heavily on the ability of its antenna – which receives electromagnetic waves – to efficiently turn waves into electricity that can power it. As such, a crucial part of improving this remote powering technology involves making the rectifier (the part of the antenna responsible for converting waves to power) work as efficiently as possible.The rectifier performance can be measured in terms of its voltage conversion efficiency, or its power conversion efficiency, where voltage refers to an electrical potential, and power here refers to the rate at which electrical energy is transferred through an electrical circuit. However, these two quantities are closely interlinked in complex ways, to such an extent that optimising one of these parameters is often done at the expense of the other, and it is not possible to optimise both parameters simultaneously. Dominik Mair and his colleagues at the University of Innsbruck in Austria, have shown in a recent publication that using either voltage or power conversion efficiency as measures of rectifier performance is not feasible. Instead, the team demonstrated that the concept of a mean conversion efficiency (the average of the voltage and power conversion efficiencies) allows optimisation algorithms to find optimum rectifier circuit designs much quicker. Not only that, but the resulting designs also show superior overall performance when compared to previous ones, even with very low power from incoming waves. The growing demand for intelligent devices that are interconnected with each other, allowing us to control our environment, is pushing the development of wireless, battery-free sensors which can gather information and even make decisions or control actuators.Q.Why does the author consider that it would have been impossible to imagine a digital world even in the late 20th century?a)There was no knowledge of characteristics like voltage and power efficiency measures during the late 20th century.b)The technology of 1980s and 1990s was incapable to cater to the dynamic idea of Internet of Things (IoT).c)It was difficult to imagine the compounding growth that technology and internet would foster over the coming periods.d)Technology was believed to be the preserve of a few fortunate sections possessing digital know-how and resources to access.Correct answer is option 'C'. Can you explain this answer? in English & in Hindi are available as part of our courses for CAT. Download more important topics, notes, lectures and mock test series for CAT Exam by signing up for free.

Here you can find the meaning of Directions: Answer the given question based on the following passage.Our digital world depends on the interconnectivity between wireless devices, often battery-free with no direct power supply. Such devices include wireless passive sensors, designed to receive and respond to signals from the environment. These devices can be powered by electromagnetic waves, provided their antenna can efficiently convert waves to energy. When Alexander Graham Bell made the first-ever phone call in 1876, calling his assistant to meet him, the connectivity of todays world would have been well beyond his wildest dreams. Perhaps even in the late 1980s and early 1990s, when the internet as we know it started to emerge, the digital world we have since built would have been unimaginable. Today, we dont just use technology to communicate with each other: we are also finding ways to make devices communicate between themselves to allow us to control our environments. The Internet of Things, as it is now called, is the combination of the immense web of sensors, devices, apps, and other technology that are connected and sharing information between them.To control our world, however, we need to be able to interconnect many devices which, for ease of installation and pleasing design, are usually wireless, including no power supply cables. For environmental reasons, it is also beneficial that these devices are battery-free. Battery-free devices can instead be powered by the electromagnetic waves they receive from the powered devices they are connected to. With the right equipment, the electromagnetic waves sent by the Wi-Fi router could be enough to supply the energy needed to power the motion sensor. Devices whose function is to detect and respond to physical signals from the surrounding environment are called passive sensors. The ability of a passive sensor to harvest energy from the environment depends heavily on the ability of its antenna – which receives electromagnetic waves – to efficiently turn waves into electricity that can power it. As such, a crucial part of improving this remote powering technology involves making the rectifier (the part of the antenna responsible for converting waves to power) work as efficiently as possible.The rectifier performance can be measured in terms of its voltage conversion efficiency, or its power conversion efficiency, where voltage refers to an electrical potential, and power here refers to the rate at which electrical energy is transferred through an electrical circuit. However, these two quantities are closely interlinked in complex ways, to such an extent that optimising one of these parameters is often done at the expense of the other, and it is not possible to optimise both parameters simultaneously. Dominik Mair and his colleagues at the University of Innsbruck in Austria, have shown in a recent publication that using either voltage or power conversion efficiency as measures of rectifier performance is not feasible. Instead, the team demonstrated that the concept of a mean conversion efficiency (the average of the voltage and power conversion efficiencies) allows optimisation algorithms to find optimum rectifier circuit designs much quicker. Not only that, but the resulting designs also show superior overall performance when compared to previous ones, even with very low power from incoming waves. The growing demand for intelligent devices that are interconnected with each other, allowing us to control our environment, is pushing the development of wireless, battery-free sensors which can gather information and even make decisions or control actuators.Q.Why does the author consider that it would have been impossible to imagine a digital world even in the late 20th century?a)There was no knowledge of characteristics like voltage and power efficiency measures during the late 20th century.b)The technology of 1980s and 1990s was incapable to cater to the dynamic idea of Internet of Things (IoT).c)It was difficult to imagine the compounding growth that technology and internet would foster over the coming periods.d)Technology was believed to be the preserve of a few fortunate sections possessing digital know-how and resources to access.Correct answer is option 'C'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of Directions: Answer the given question based on the following passage.Our digital world depends on the interconnectivity between wireless devices, often battery-free with no direct power supply. Such devices include wireless passive sensors, designed to receive and respond to signals from the environment. These devices can be powered by electromagnetic waves, provided their antenna can efficiently convert waves to energy. When Alexander Graham Bell made the first-ever phone call in 1876, calling his assistant to meet him, the connectivity of todays world would have been well beyond his wildest dreams. Perhaps even in the late 1980s and early 1990s, when the internet as we know it started to emerge, the digital world we have since built would have been unimaginable. Today, we dont just use technology to communicate with each other: we are also finding ways to make devices communicate between themselves to allow us to control our environments. The Internet of Things, as it is now called, is the combination of the immense web of sensors, devices, apps, and other technology that are connected and sharing information between them.To control our world, however, we need to be able to interconnect many devices which, for ease of installation and pleasing design, are usually wireless, including no power supply cables. For environmental reasons, it is also beneficial that these devices are battery-free. Battery-free devices can instead be powered by the electromagnetic waves they receive from the powered devices they are connected to. With the right equipment, the electromagnetic waves sent by the Wi-Fi router could be enough to supply the energy needed to power the motion sensor. Devices whose function is to detect and respond to physical signals from the surrounding environment are called passive sensors. The ability of a passive sensor to harvest energy from the environment depends heavily on the ability of its antenna – which receives electromagnetic waves – to efficiently turn waves into electricity that can power it. As such, a crucial part of improving this remote powering technology involves making the rectifier (the part of the antenna responsible for converting waves to power) work as efficiently as possible.The rectifier performance can be measured in terms of its voltage conversion efficiency, or its power conversion efficiency, where voltage refers to an electrical potential, and power here refers to the rate at which electrical energy is transferred through an electrical circuit. However, these two quantities are closely interlinked in complex ways, to such an extent that optimising one of these parameters is often done at the expense of the other, and it is not possible to optimise both parameters simultaneously. Dominik Mair and his colleagues at the University of Innsbruck in Austria, have shown in a recent publication that using either voltage or power conversion efficiency as measures of rectifier performance is not feasible. Instead, the team demonstrated that the concept of a mean conversion efficiency (the average of the voltage and power conversion efficiencies) allows optimisation algorithms to find optimum rectifier circuit designs much quicker. Not only that, but the resulting designs also show superior overall performance when compared to previous ones, even with very low power from incoming waves. The growing demand for intelligent devices that are interconnected with each other, allowing us to control our environment, is pushing the development of wireless, battery-free sensors which can gather information and even make decisions or control actuators.Q.Why does the author consider that it would have been impossible to imagine a digital world even in the late 20th century?a)There was no knowledge of characteristics like voltage and power efficiency measures during the late 20th century.b)The technology of 1980s and 1990s was incapable to cater to the dynamic idea of Internet of Things (IoT).c)It was difficult to imagine the compounding growth that technology and internet would foster over the coming periods.d)Technology was believed to be the preserve of a few fortunate sections possessing digital know-how and resources to access.Correct answer is option 'C'. Can you explain this answer?, a detailed solution for Directions: Answer the given question based on the following passage.Our digital world depends on the interconnectivity between wireless devices, often battery-free with no direct power supply. Such devices include wireless passive sensors, designed to receive and respond to signals from the environment. These devices can be powered by electromagnetic waves, provided their antenna can efficiently convert waves to energy. When Alexander Graham Bell made the first-ever phone call in 1876, calling his assistant to meet him, the connectivity of todays world would have been well beyond his wildest dreams. Perhaps even in the late 1980s and early 1990s, when the internet as we know it started to emerge, the digital world we have since built would have been unimaginable. Today, we dont just use technology to communicate with each other: we are also finding ways to make devices communicate between themselves to allow us to control our environments. The Internet of Things, as it is now called, is the combination of the immense web of sensors, devices, apps, and other technology that are connected and sharing information between them.To control our world, however, we need to be able to interconnect many devices which, for ease of installation and pleasing design, are usually wireless, including no power supply cables. For environmental reasons, it is also beneficial that these devices are battery-free. Battery-free devices can instead be powered by the electromagnetic waves they receive from the powered devices they are connected to. With the right equipment, the electromagnetic waves sent by the Wi-Fi router could be enough to supply the energy needed to power the motion sensor. Devices whose function is to detect and respond to physical signals from the surrounding environment are called passive sensors. The ability of a passive sensor to harvest energy from the environment depends heavily on the ability of its antenna – which receives electromagnetic waves – to efficiently turn waves into electricity that can power it. As such, a crucial part of improving this remote powering technology involves making the rectifier (the part of the antenna responsible for converting waves to power) work as efficiently as possible.The rectifier performance can be measured in terms of its voltage conversion efficiency, or its power conversion efficiency, where voltage refers to an electrical potential, and power here refers to the rate at which electrical energy is transferred through an electrical circuit. However, these two quantities are closely interlinked in complex ways, to such an extent that optimising one of these parameters is often done at the expense of the other, and it is not possible to optimise both parameters simultaneously. Dominik Mair and his colleagues at the University of Innsbruck in Austria, have shown in a recent publication that using either voltage or power conversion efficiency as measures of rectifier performance is not feasible. Instead, the team demonstrated that the concept of a mean conversion efficiency (the average of the voltage and power conversion efficiencies) allows optimisation algorithms to find optimum rectifier circuit designs much quicker. Not only that, but the resulting designs also show superior overall performance when compared to previous ones, even with very low power from incoming waves. The growing demand for intelligent devices that are interconnected with each other, allowing us to control our environment, is pushing the development of wireless, battery-free sensors which can gather information and even make decisions or control actuators.Q.Why does the author consider that it would have been impossible to imagine a digital world even in the late 20th century?a)There was no knowledge of characteristics like voltage and power efficiency measures during the late 20th century.b)The technology of 1980s and 1990s was incapable to cater to the dynamic idea of Internet of Things (IoT).c)It was difficult to imagine the compounding growth that technology and internet would foster over the coming periods.d)Technology was believed to be the preserve of a few fortunate sections possessing digital know-how and resources to access.Correct answer is option 'C'. Can you explain this answer? has been provided alongside types of Directions: Answer the given question based on the following passage.Our digital world depends on the interconnectivity between wireless devices, often battery-free with no direct power supply. Such devices include wireless passive sensors, designed to receive and respond to signals from the environment. These devices can be powered by electromagnetic waves, provided their antenna can efficiently convert waves to energy. When Alexander Graham Bell made the first-ever phone call in 1876, calling his assistant to meet him, the connectivity of todays world would have been well beyond his wildest dreams. Perhaps even in the late 1980s and early 1990s, when the internet as we know it started to emerge, the digital world we have since built would have been unimaginable. Today, we dont just use technology to communicate with each other: we are also finding ways to make devices communicate between themselves to allow us to control our environments. The Internet of Things, as it is now called, is the combination of the immense web of sensors, devices, apps, and other technology that are connected and sharing information between them.To control our world, however, we need to be able to interconnect many devices which, for ease of installation and pleasing design, are usually wireless, including no power supply cables. For environmental reasons, it is also beneficial that these devices are battery-free. Battery-free devices can instead be powered by the electromagnetic waves they receive from the powered devices they are connected to. With the right equipment, the electromagnetic waves sent by the Wi-Fi router could be enough to supply the energy needed to power the motion sensor. Devices whose function is to detect and respond to physical signals from the surrounding environment are called passive sensors. The ability of a passive sensor to harvest energy from the environment depends heavily on the ability of its antenna – which receives electromagnetic waves – to efficiently turn waves into electricity that can power it. As such, a crucial part of improving this remote powering technology involves making the rectifier (the part of the antenna responsible for converting waves to power) work as efficiently as possible.The rectifier performance can be measured in terms of its voltage conversion efficiency, or its power conversion efficiency, where voltage refers to an electrical potential, and power here refers to the rate at which electrical energy is transferred through an electrical circuit. However, these two quantities are closely interlinked in complex ways, to such an extent that optimising one of these parameters is often done at the expense of the other, and it is not possible to optimise both parameters simultaneously. Dominik Mair and his colleagues at the University of Innsbruck in Austria, have shown in a recent publication that using either voltage or power conversion efficiency as measures of rectifier performance is not feasible. Instead, the team demonstrated that the concept of a mean conversion efficiency (the average of the voltage and power conversion efficiencies) allows optimisation algorithms to find optimum rectifier circuit designs much quicker. Not only that, but the resulting designs also show superior overall performance when compared to previous ones, even with very low power from incoming waves. The growing demand for intelligent devices that are interconnected with each other, allowing us to control our environment, is pushing the development of wireless, battery-free sensors which can gather information and even make decisions or control actuators.Q.Why does the author consider that it would have been impossible to imagine a digital world even in the late 20th century?a)There was no knowledge of characteristics like voltage and power efficiency measures during the late 20th century.b)The technology of 1980s and 1990s was incapable to cater to the dynamic idea of Internet of Things (IoT).c)It was difficult to imagine the compounding growth that technology and internet would foster over the coming periods.d)Technology was believed to be the preserve of a few fortunate sections possessing digital know-how and resources to access.Correct answer is option 'C'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice Directions: Answer the given question based on the following passage.Our digital world depends on the interconnectivity between wireless devices, often battery-free with no direct power supply. Such devices include wireless passive sensors, designed to receive and respond to signals from the environment. These devices can be powered by electromagnetic waves, provided their antenna can efficiently convert waves to energy. When Alexander Graham Bell made the first-ever phone call in 1876, calling his assistant to meet him, the connectivity of todays world would have been well beyond his wildest dreams. Perhaps even in the late 1980s and early 1990s, when the internet as we know it started to emerge, the digital world we have since built would have been unimaginable. Today, we dont just use technology to communicate with each other: we are also finding ways to make devices communicate between themselves to allow us to control our environments. The Internet of Things, as it is now called, is the combination of the immense web of sensors, devices, apps, and other technology that are connected and sharing information between them.To control our world, however, we need to be able to interconnect many devices which, for ease of installation and pleasing design, are usually wireless, including no power supply cables. For environmental reasons, it is also beneficial that these devices are battery-free. Battery-free devices can instead be powered by the electromagnetic waves they receive from the powered devices they are connected to. With the right equipment, the electromagnetic waves sent by the Wi-Fi router could be enough to supply the energy needed to power the motion sensor. Devices whose function is to detect and respond to physical signals from the surrounding environment are called passive sensors. The ability of a passive sensor to harvest energy from the environment depends heavily on the ability of its antenna – which receives electromagnetic waves – to efficiently turn waves into electricity that can power it. As such, a crucial part of improving this remote powering technology involves making the rectifier (the part of the antenna responsible for converting waves to power) work as efficiently as possible.The rectifier performance can be measured in terms of its voltage conversion efficiency, or its power conversion efficiency, where voltage refers to an electrical potential, and power here refers to the rate at which electrical energy is transferred through an electrical circuit. However, these two quantities are closely interlinked in complex ways, to such an extent that optimising one of these parameters is often done at the expense of the other, and it is not possible to optimise both parameters simultaneously. Dominik Mair and his colleagues at the University of Innsbruck in Austria, have shown in a recent publication that using either voltage or power conversion efficiency as measures of rectifier performance is not feasible. Instead, the team demonstrated that the concept of a mean conversion efficiency (the average of the voltage and power conversion efficiencies) allows optimisation algorithms to find optimum rectifier circuit designs much quicker. Not only that, but the resulting designs also show superior overall performance when compared to previous ones, even with very low power from incoming waves. The growing demand for intelligent devices that are interconnected with each other, allowing us to control our environment, is pushing the development of wireless, battery-free sensors which can gather information and even make decisions or control actuators.Q.Why does the author consider that it would have been impossible to imagine a digital world even in the late 20th century?a)There was no knowledge of characteristics like voltage and power efficiency measures during the late 20th century.b)The technology of 1980s and 1990s was incapable to cater to the dynamic idea of Internet of Things (IoT).c)It was difficult to imagine the compounding growth that technology and internet would foster over the coming periods.d)Technology was believed to be the preserve of a few fortunate sections possessing digital know-how and resources to access.Correct answer is option 'C'. Can you explain this answer? tests, examples and also practice CAT tests.