1. What is a transducer?
a) A device that converts physical quantities into electrical signals
b) A device that amplifies electrical signals
c) A device that stores electrical energy
d) A device that controls digital systems
Answer: a) A device that converts physical quantities into electrical signals
Explanation: Transducers are devices that convert one form of energy into another. In the context of sensors, transducers convert physical quantities like temperature, pressure, or light into electrical signals that can be measured and analyzed.
2. Which of the following is NOT a type of sensor?
a) Proximity sensor
b) Temperature sensor
c) Amplifier sensor
d) Light sensor
Answer: c) Amplifier sensor
Explanation: Sensors detect and respond to physical stimuli, such as light, temperature, or proximity. An “amplifier sensor” is not a recognized type of sensor; amplifiers typically enhance electrical signals but do not directly detect physical quantities.
3. How do light sensors work?
a) By emitting light rays
b) By detecting changes in electrical resistance
c) By converting light into electrical signals
d) By measuring air pressure
Answer: c) By converting light into electrical signals
Explanation: Light sensors, also known as photodetectors, work by converting incident light into electrical signals. Common types include photodiodes and phototransistors, which generate current or voltage proportional to the intensity of light they receive.
4. What is the primary function of proximity sensors?
a) To measure temperature
b) To detect nearby objects
c) To sense changes in humidity
d) To monitor air quality
Answer: b) To detect nearby objects
Explanation: Proximity sensors are designed to detect the presence or absence of nearby objects without physical contact. They often use various technologies such as infrared, ultrasonic, or capacitive sensing to accomplish this task.
5. What phenomenon do Hall effect sensors rely on?
a) Temperature variation
b) Light reflection
c) Magnetic fields
d) Sound waves
Answer: c) Magnetic fields
Explanation: Hall effect sensors operate based on the Hall effect, which describes the generation of a voltage difference (Hall voltage) across an electrical conductor when subjected to a magnetic field perpendicular to the current flow. This principle is utilized in Hall effect sensors to detect magnetic fields.
6. In which numbering system is digital information represented using only two symbols?
a) Decimal
b) Binary
c) Octal
d) Hexadecimal
Answer: b) Binary
Explanation: Binary is a numbering system that uses only two symbols, typically represented as 0 and 1. It is widely used in digital systems due to its simplicity and compatibility with electronic circuits.
7. What is the hexadecimal equivalent of the binary number 1010?
a) A
b) 10
c) B
d) 101
Answer: a) A
Explanation: In hexadecimal, the binary number 1010 is equivalent to the digit A. Hexadecimal numbering system uses digits 0-9 and letters A-F to represent values from 0 to 15.
8. Which logic gate performs the operation of addition in binary arithmetic?
a) AND gate
b) OR gate
c) XOR gate
d) NOT gate
Answer: c) XOR gate
Explanation: XOR (exclusive OR) gate performs the addition operation in binary arithmetic. It outputs true (1) only when the number of true inputs is odd, making it suitable for addition in digital circuits.
9. What do control systems primarily regulate?
a) Electrical conductivity
b) Mechanical motion
c) Chemical reactions
d) Thermal expansion
Answer: b) Mechanical motion
Explanation: Control systems are designed to regulate and manipulate physical processes or systems, primarily focusing on aspects like mechanical motion, such as speed, position, or direction, in various applications ranging from industrial automation to robotics.
10. What is the basic unit of data representation in digital systems?
a) Bit
b) Byte
c) Megabyte
d) Kilobyte
Answer: a) Bit
Explanation: A bit (binary digit) is the fundamental unit of information in digital systems. It can represent two distinct states: 0 or 1, corresponding to off or on, false or true, etc. Multiple bits are grouped together to represent larger units of data, such as bytes, kilobytes, etc.