Electronics Technician(Evaluations and answers),Version 1 ,Mid course-test ,End-course Revision.234

Who is credited with having been among the first to observe the attraction of amber for small fibrous materials and bits of straw? - answer-Thales of Miletus (640-546 B.C.) What is the Greek word for Ambera solidified tree sap? - answer-Elektron, (The root word for electricity) Who in the 17th Century announced the discovery that many substances could be electrified by friction? - answer-Sir William Gilbert () What is the name of Sir Williams Gilbert's book? - answer-De Magnete all fundamental properties of electricity and magnetism can be traced to the state or motion of what term? - answer-Electric charge Who discovered that a glass rod and a wax rod possessed two different kinds of electrical "fluid"? - answer-Charles F. DuFay () In the eighteenth century,Who introduced the terms positive (+) and negative (-) to describe the two types of electricity - answer-Benjamin Franklin () In 1785, which physicist proved the laws of attraction and repulsion that exist between positive and negative electric charges - answer-Charles Augustin de Coulomb () What Law states that the force acting between two charges is directly proportional to the product of the two charges and inversely proportional to the square of the distance between the charges - answer-Coulomb's law In 1786, who found that a frog's leg could be made to twitch if copper and iron were brought into contact with a nerve and a muscle? - answer-Luigi Galvani What did Luigi Galvani name his discovery involving the frogs leg? - answer-animal electricity In 1796, who proved that electricity could be produced if unlike metals separated by moistened paper were brought into contact? - answer-Alessandro Volta What arrangement became known as the voltaic pile? - answer-Alessandro Volta stacked pairs of unlike metals on top of each other in order to increase the intensity of the electric charge. This was the first battery What was uncovered by Hans Christian Oersted in 1820? - answer-The first significant connection between magnetism and electricity.Oersted accidentally discovered that a current-carrying wire influenced the orientation of a nearby compass needle. What became known as electromagnetism? - answer-Magnetic fields to the motion of electric charges In 1826, What did German physicist Georg Simon Ohm observe? And what did this observation become known as? - answer-The electrical resistance of metallic conductors remains constant over wide ranges of potential difference. This observation became known as Ohm's law. Two scientists are given credit for the discovery of electromagnetic induction. What are there names? - answer-Michael Faraday (), and Joseph Henry () What are the laws of electromagnetic induction called? - answer-Faraday's laws What as Gustav Kirchhoff well known for? - answer-His contributions to circuit theory and the understanding of thermal emission, and also his significant discoveries in optics Who considered an electrical network consisting of circuits joined at nodes of the network and gave laws which reduce the calculation of the currents in each loop to the solution of algebraic equations - answer-Gustav Kirchhoff What year was the "Geissler tubes" developed? - answer-1868 In a "Geissler tube" electrical discharges in rarefied gases would produce what? - answer-Different colors What is Sir William Crookes widely credited with? - answer-Being the inventor of the first cathode ray tube What did Thomas Edison discover when he inserted an electrode in a glass bulb with a filament? - answer-He found that a current would flow if a positive potential was applied to the electrode and the filament was hot. Edison also noted that no current would flow if the filament was cold. What led to the invention of the electronic vacuum tube? - answer-Thomas Edisons incadescent light buld experiment with an electrode and a filament What is the Fleming valve also known as? - answer-A vacuum-tube rectifier, or diode What is to used to change alternating current into direct current. - answer-A fleming valve (Also known as a vacuum-tube rectifier, or diode) The first vacuum tube capable of boosting, or amplifying, small electrical signals was patented in 1907 by who? - answer-Lee de Forest What type of vacuum tube used by Lee de Forest in 1907? - answer-A triode tube What was invented by the German scientist Walter Schottky in 1916? - answer-The tetrode tube Schottky is credited with a great many inventions during his career, among them the first what? in 1938. - answer-semiconductor diode In 1947 three American scientists invented what? - answer-The transistor What discovery ushered in the era of solid-state electronics? - answer-The transistor What are the names of the three American scientists who in 1947 invented the transistor? - answer-John Bardeen, Walter Brattain, and William Shockley What does IC stand for? - answer-Integrated circuit In 1958 the integrated circuit (IC) was developed by which four scientists? - answer-Jean Hoerni, Jack Kilby, Kurt Lehovec, and Robert Noyce The development of the IC led to the invention of what device by Ted Hoff in 1971? - answer-The microprocessor In 1979 who began marketing a powerful 16-bit microprocessor? - answer-Motorola Corporation What is a single-atom transistor? - answer-A transistor in which electrons flow through a single atom What is one of the most common integrated circuits used in consumer, commercial and industrial electronics circuits? - answer-The microprocessor What recent developments now make it possible to transmit data thousands of miles at the speed of light? - answer-Fiber optic communications What type of communication sytem allows for the instantaneous transmission of video, audio, and data to virtually anywhere on earth? - answer-Satellite communications systems What electronic device did the modern electronic computer started with? - answer-ENIAC (Electronic Numerical Integrator and Calculator) completed in 1946 by J. Presper Eckert and John Mauchly at the University of Pennsylvania What does the term information technology, or IT, refer to? - answer-The hardware and software that are used to store, retrieve and manipulate information What percentage of the wealth created in the United States comes from manufacturing? - answer-Approximately two-thirds What are Two of the most common automation machines used in industry? - answer-Programmable logic controllers (PLCs) and robots What is a PLC? - answer-PLCs are machines which are programmed to allow various input devices such as switches and sensors to control output devices such as motors and solenoid valves Consumer electronics products are electronics equipment that are intended to be used how often? - answer-Daily The development of what two display screens revolutionized video broadcasting and led to the rapid deployment of digital television - answer-LCD and Plasma In the latter part of the 20th century, what medium made use of magnetic tape for recording? - answer-The VCR What is a small hand-held computer typically providing calendar, contacts, and note- taking applications known as? - answer-P.D.A What type of electronics are used for such medical applications as diagnosis, therapy, research, anaesthesia control, cardiac control, and surgery? - answer-Medical Electronics What was the The first major development in medical electronics? - answer-The X-Ray In 1895 who discovered the X-Ray? - answer-German scientist Wilhelm Roentgen What device isused for a non-intrusive examination of the internal organs of patients? - answer-The X-Ray Machine What led to the which led to the invention of magnetic resonance imaging (MRI)? - answer-The discoery that atoms in living tissue will emit resonant RF signals in the presence of strong magnetic fields and radio waves What is radiology? - answer-The use of radiation (such as x-ray machines) or other imaging technologies (such as ultrasound and magnetic resonance imaging) to diagnose or treat disease What devices are either made of carbon-composition or wound with special wire wrapped around a ceramic-core form? - answer-Resistors What device is capable of storing electrical charge and is popular in electronic circuits where filtering is required? - answer-A Capacitor What Device offers filtering properties that include blocking DC current and passing AC current, or smoothing out voltages produced by rectifiers and power supplies? - answer-A Capacitor What is another name for the electronic components known as coils, or chokes? - answer-Inductors What are inductors used for? - answer-Storing energy in an electromagnetic field Name three quantities that can be proven to exist without the use of any measuring instruments. - answer-Mass, Length and Time Name three quantities known as fundamental quantities - answer-Mass, Length and Time Quantities that are obtained from the fundamental quantities are referred to as what? - answer-Derived quantities Name three sytems of measurment - answer-The MKS system, the CGS system, and the English system of units The International System of Units, or SI, represents a rationalized selection of the MKS system and is commonly referred as what? - answer-The metric system