_______ is a controlled electronic switch fabricated using a semiconductor.
Transistor
Understanding Controlled Electronic Switches
The question asks us to identify a device that is a controlled electronic switch and is made using a semiconductor material. Let's look at the options provided and see which one fits this description.
First, let's understand the key terms:
- Semiconductor: A material that has electrical conductivity between that of a conductor (like metal) and an insulator (like glass). Common semiconductor materials include silicon and germanium.
- Controlled electronic switch: An electronic component that can turn an electrical signal or current on or off, where this switching action is controlled by another electrical signal.
Analyzing the Options
Let's examine each option:
- Transistor: A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. Transistors are fundamental building blocks of electronic devices. They are made from semiconductor materials and can function as controlled switches, allowing a small signal to control a larger current flow.
- Hard-disk: A hard-disk drive (HDD) is a data storage device used for storing and retrieving digital information using magnetic storage. It is not an electronic switch.
- Monitor: A monitor is an output device that displays information in pictorial form. It is not an electronic switch.
- Coupler: A coupler is a device that connects two parts or systems. In electronics, it could refer to various devices (like optical couplers, directional couplers), but a general "coupler" is not primarily defined as a controlled electronic switch made from a semiconductor, although some specific types might incorporate semiconductor components. The description in the question specifically points to a fundamental semiconductor switching device.
Conclusion on the Controlled Electronic Switch
Based on the analysis, the device that is widely known as a controlled electronic switch fabricated using a semiconductor is a Transistor.
Transistors are the core components used in almost all modern electronic circuits for switching applications, from simple on/off functions to complex digital logic gates in microprocessors.
| Device | Semiconductor? | Controlled Electronic Switch? |
|---|---|---|
| Transistor | Yes | Yes |
| Hard-disk | No (primarily magnetic/mechanical) | No |
| Monitor | No (primarily display technology) | No |
| Coupler | Generally No (role is connection, not switching) | No (not its primary function/definition) |
Revision Table: Electronic Switches and Semiconductors
It is important to remember the functions of basic electronic components for exam preparation.
| Component Type | Primary Function | Made of Semiconductor? | Example |
|---|---|---|---|
| Resistor | Oppose current flow | No (typically carbon, metal film) | Fixed Resistor |
| Capacitor | Store electrical energy | No (dielectric material) | Ceramic Capacitor |
| Inductor | Store magnetic energy | No (coil of wire) | Solenoid |
| Diode | Allow current flow in one direction | Yes | PN junction diode |
| Transistor | Amplify or switch electronic signals | Yes | BJT, MOSFET |
Additional Information: Types of Transistors
Transistors are broadly classified into two main types:
- Bipolar Junction Transistors (BJTs): These transistors use both electrons and holes as charge carriers. They include NPN and PNP types.
- Field-Effect Transistors (FETs): These transistors use only one type of charge carrier (either electrons or holes). They include MOSFETs (Metal-Oxide-Semiconductor FETs) and JFETs (Junction FETs). MOSFETs are the most common type of transistor used in digital circuits today, primarily functioning as electronic switches.
Both BJTs and FETs are fabricated using semiconductor materials like silicon and serve as fundamental controlled electronic switches or amplifiers in circuits.
Important Questions from Miscellaneous
A stone is thrown horizontally from the top of a 20 m high building with a speed of 12 m/s. It hits the ground at a distance R from the building. Taking g = 10 m/s2 and neglecting air resistance will give :
A sphere of volume V is made of a material with lower density than water. While on Earth, it floats on water with its volume f1V (f1 < 1) submerged. On the other hand, on a spaceship accelerating with acceleration a < g (g is the acceleration due to gravity on Earth) in outer space, its submerged volume in water is f2V. Then:
A railway wagon (open at the top) of mass M1 is moving with speed v1 along a straight track. As a result of rain, after some time it gets partially filled with water so that the mass of the wagon becomes M2 and speed becomes v2. Taking the rain to be falling vertically and the water stationery inside the wagon, the relation between the two speeds v1 and v2 is :
Consider the following statements:
1. Distance between the longitudes becomes zero on North Pole and South Pole.
2. Distance between the longitudes is maximum on the Equator.
3. Number of longitudes is more than number of latitudes.
Which of the statements given above is/are correct?
One block of 2⋅0 kg mass is placed on top of another block of 3⋅0 kg mass. The coefficient of static friction between the two blocks is 0⋅2. The bottom block is pulled with a horizontal force F such that both the blocks move together without slipping. Taking acceleration due to gravity as 10 m/s2, the maximum value of the frictional force is :
