Description : What is meant by referring to electromagnetic waves as horizontally polarized? A. The electric field is parallel to the earth. B. The magnetic field is parallel to the earth. C. Both the electric and magnetic fields are horizontal D. Both the electric and magnetic fields are vertical
Last Answer : A. The electric field is parallel to the earth.
Description : What are electromagnetic waves? A. Alternating currents in the core of an electromagnet B. A wave consisting of two electric fields at right angles to each other C. A wave consisting of an electric field ... to each other D. A wave consisting of two magnetic fields at right angles to each other
Last Answer : C. A wave consisting of an electric field and a magnetic field at right angles to each other
Description : What are electromagnetic waves? A. A wave consisting of two magnetic fields at right angles to each other B. A wave consisting of an electric field and a magnetic field at right angles to each ... core of an electromagnet D. A wave consisting of two electric fields at right angles to each other
Last Answer : B. A wave consisting of an electric field and a magnetic field at right angles to each other.
Description : What is meant by referring to electromagnetic waves as horizontally polarized? A. The electric field is parallel to the earth B. Both the electric and magnetic fields are vertical C. Both the electric and magnetic fields are horizontal D. The magnetic fields is parallel to the earth
Last Answer : A. The electric field is parallel to the earth
Description : The waves associated with electric and magnetic fields, resulting from the acceleration of an electric charge are called
Last Answer : electromagnetic waves.
Description : Which one of the following statement is incorrect regarding the electromagnetic radiation? (A) These are produced by the motion of electric charge (B) The oscillation of charged particles sets up ... electric fields induce the changing magnetic fields in the surrounding medium (D) None of these
Last Answer : Answer: Option D
Description : Magnetic fields are produced by: w) resistance x) an electric potential difference y) electric current z) stationary charge
Last Answer : ANSWER: Y -- CURRENT
Description : Ultrasonic waves are produced by making use of - (1) ferro magnetic material (2) ferri magnetic material (3) piezo electric material (4) pyro electrical material
Last Answer : (3) piezo electric material Explanation: In most applications, ultrasonic waves are generated by a transducer that includes a piezoelectric material (crystal) that converts electrical energy (electric current) to mechanical energy (sound waves).
Description : Why are we able to hear shortwave broadcasts better than long wave broadcasts? (a) Short wave broadcasts are made by nearby radio stations (b) Short waves are unaffected by atmospheric ... convention, short waves are meant for long distances whereas long waves are reserved for short distances
Last Answer : Ans:(c) Direction: In the following question, a statement of Assertion (A) is given followed by corresponding Reason (R), just below it. Read the statements carefully and mark the correct answer: (a) If both A and ... true but R is not the correct explanation of A. (c) If A is true but R is false
Description : Why are we able to hear short wave broadcasts better than long wave broadcasts? (1) Short waves are more energetic than long waves (2) Short waves are unaffected by atmospheric disturbances ... convention, short waves are meant for long distances, whereas long waves are reserved for short distances
Last Answer : (1) Short waves are more energetic than long waves Explanation: Shortwave radio is used for broadcasting of voice and music, and longdistance communication to ships and aircraft, or to remote areas ... wired communication or other radio services and that's why it is more energetic than long waves.
Description : Why are we able to hear short wave broadcasts better than long wave broadcasts ? (1) Short waves are more energetic than long waves. (2) Short waves are unaffected by atmospheric ... convention, short waves are meant for long distances, whereas long waves are reserved for short distances.
Last Answer : Short waves are more energetic than long waves.
Description : Mirage is due to (a) Unequal heating of different parts of the atmosphere (b) Magnetic disturbances in the atmosphere (c) Depletion of ozone layer in the atmosphere (d) Equal heating of different parts of the atmosphere
Last Answer : Ans:(a)
Description : What are the OBSERVED differences between electric and magnetic fields?
Last Answer : answer:A changing magnetic field creates an electric current (a flow of electrically charged material). A changing electric current, in turn, creates a magnetic field.
Description : In a cathode ray tube, electric and magnesity of the magnetic fields are simultaneously applied at right angles to each other and the intensity of the
Last Answer : In a cathode ray tube, electric and magnesity of the magnetic fields are simultaneously applied at right angles to each ... 01 T` and `E=50,000 V//m`.
Description : The forces of cathode ray particles due to electric and magnetic fields which are at right angles to each other balance each other. If the magnetic fi
Last Answer : The forces of cathode ray particles due to electric and magnetic fields which are at right angles to ... p.d. is required to produce this velocity?
Description : A charged particle with a velocity `2xx10^(3) ms^(-1)` passes undeflected through electric field and magnetic fields in mutually perpendicular directi
Last Answer : A charged particle with a velocity `2xx10^(3) ms^(-1)` passes undeflected through electric field and magnetic fields ... 1)` D. `1.33xx10^(3)NC^(-1)`
Description : An electromagnetic wave consists of A. a magnetic field only B. both electric and magnetic fields C. an electric field only D. non-magnetic field only
Last Answer : B. both electric and magnetic fields
Description : Fields that act on objects with masses are A. electric fieldsB. magnetic fields C. force fields D. gravitational fields
Last Answer : gravitational fields
Description : The electric and magnetic fields vary with time in which of the following fields? a) DC b) AC c) Static d) It does not vary with time
Last Answer : b) AC
Description : The phase shift in the electric and magnetic fields in an EM wave is given by which parameter? a) phase constant b) attenuation constant c) propagation constant d) intrinsic impedance
Last Answer : d) intrinsic impedance
Description : In good conductors, the electric and magnetic fields will be a) 45 in phase b) 45 out of phase c) 90 in phase d) 90 out of phase
Last Answer : b) 45 out of phase
Description : In electric fields, D= ε E. The correct expression which is analogous in magnetic fields will be a) H = μ B b) B = μ H c) A = μ B d) H = μ A
Last Answer : b) B = μ H
Description : In an electromagnetic wave, what is the relative orientation of the magnetic and electric fields? w) 180 degrees x) 90 degrees y) 45 degrees z) 22.5 degrees
Last Answer : ANSWER: X -- 90 DEGREES
Description : Indicate the false statement. A. Industrial noise is usually of the impulse type B. Static is caused by lightning discharges in thunderstorms and other natural electric disturbances occurring in the ... another source of man-made noise D. Flourescent lights are another source of man-made noise
Last Answer : C. Distant stars are another source of man-made noise
Description : Moving electric charge produces - (1) magnetic field (2) sound waves (3) light rays (4) heat waves
Last Answer : (1) magnetic field Explanation: An electric charge always produces an electric field, regardless of speed, and a moving charge generates a magnetic field. An electric current passing through a conductor produces a magnetic field because it has many charges in motion.
Description : Radio waves, microwaves, infra-red spectrum, ultraviolet rays, X-rays and gamma rays are classified as ______. (1) light waves (2) electromagnetic waves (3) electric waves (4) magnetic waves
Last Answer : (2) electromagnetic waves Explanation: Electromagnetic radiation is the radiant energy released by certain electromagnetic processes. It consists of electromagnetic waves which are synchronized oscillations of electric and magnetic fields that propagate at the speed of light through a vacuum.
Description : In electromagnetic waves, the electric field will be perpendicular to which of the following? a) Magnetic field intensity b) Wave propagation c) Both H and wave direction d) It propagates independently
Last Answer : c) Both H and wave direction
Description : Moving electric charge produces : (1) magnetic field (2) sound waves (3) light rays (4) heat waves
Last Answer : magnetic field
Description : The amount of mechanical force or torque produced by an electric motor depends on the ________________. A. strength of its magnetic field B. amount of armature current flow C. length of conductor in the field D. all of the above
Last Answer : Answer: D
Description : Magnetic field can be produced by using A. permanent magnet B. electric current C. temporary magnet D. both A and B
Last Answer : permanent magnet
Description : How do magnetic fields around connected conductive materials take shape?
Last Answer : I think that while the current supplied by the wire is flowing through the metal balls they will generate a magnetic field in the same way a field surrounds a wire with electricity flowing through it. ... that in the same way it passes between atoms in a wire their magnetism will not repel them.
Description : 7. List two methods of producing magnetic fields. -Physics-10
Last Answer : Following are the methods of producing magnetic fields: By using a permanent magnet we can produce magnetic field and it can be visualized by spreading iron fillings on a white paper and keeping a ... conductors such as solenoid and circular loop can be used to see the presence of magnetic field.
Description : What type of star have extremely intense gravitational and magnetic fields?
Last Answer : Feel Free to Answer
Description : What is the relationship between the strength of magnetic fields and the distance between 2 magnets?
Last Answer : Need answer
Description : In troubleshooting a circuit in a console, you find that a resistor may be faulty. Which of the precautions listed must be observed when using an ohmmeter to carry out this test? A. Correct polarity ... D. The resistor's circuit must be de-energized and at least one end of the component isolated.
Description : While troubleshooting a circuit in an engine room central control console, a resistor is suspected of being faulty. Which of the following precautions must be observed if an ohmmeter is to be used to ... of the component isolated. D. The meter case must be grounded prior to attaching the leads.
Last Answer : Answer: C
Description : Which of the substances listed can be used to shield sensitive equipment from static magnetic fields? A. Glass B. Mica C. Bakelite D. Permeable iron
Description : For more complete vessel protection when using an impressed current cathodic system _____________. A. all ship's service alternators have additional temperature sensing devices and a thermal recorder ... with the hull and the propeller shaft is grounded through a slip ring/brush arrangement
Description : The purpose of an impressed current cathodic protection system aboard ship is to _______________. A. prevent corrosion of the hull, propeller, rudder and line shafting B. neutralize the vessel's ... the presence of salt air D. maintain a minimum constant alternator load to prevent overheating
Last Answer : Answer: A
Description : One method of testing for a reversed shunt field coil in a DC generator or motor is by connecting the field to a direct current source, at reduced field rated voltage, and test for ... placed near each field C. test lamp across adjacent fields D. copper jumper across the interpole connections
Last Answer : Answer: B
Description : The polarization of a radio wave: A. Is perpendicular to the electrostatic field of the antenna B. Is the same direction as the electrostatic field of the antenna. C. Is the same direction ... field of the antenna. D. Is perpendicular to both the electrostatic and magnetic fields of the antenna.
Last Answer : B. Is the same direction as the electrostatic field of the antenna.
Description : When current is parallel to magnetic fields, force on conductor is A. zeroB. infinite C. 2 times D. same
Last Answer : zero
Description : It cannot be determined from Gauss law, whereas the remaining options can be computed from Gauss law. 10. Gauss law for magnetic fields is given by a) Div(E) = 0 b) Div(B) = 0 c) Div(H) = 0 d) Div(D) = 0
Last Answer : b) Div(B) = 0
Description : The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic fields (a) meter is surrounded by strong magnetic fields (b) a soft ... is used (c) a plastic shielding is provided (d) a shielding of anon-magnetic material is used
Last Answer : (b) a soft iron shielding is used
Description : Why should you never place floppy disks near telephones or other electronic equipments that generate magnetic fields?
Last Answer : Magnetic fields can destroy the data on a disk.
Description : What is that instrument used for measuring the strength and direction of magnetic fields?
Last Answer : magnetometer
Description : Type of power-line frequency meter device utilizing a principle of balancing an indicator needle at center of a scale using magnetic fields opposing each other.
Last Answer : magnetic type
Description : The relative speed between the magnetic fields of stator and rotor under steady state operation is zero for a (A) dc machine. (B) 3 phase induction machine. (C) synchronous machine. (D) single phase induction machine.
Last Answer : Ans: all options are correct
Description : Optic fibres are used in place of wire cables because (1) they generate strong magnetic fields (2) they do not generate magnetic fields (3) they do not require boosting (4) they are more economical
Last Answer : they do not generate magnetic fields
Description : The effect of stray magnetic fields on the actuating torque of a portable instrument is maximum when the operating field of the instrument and the stray fields are A) Perpendicular B) Parallel C) Inclined at 60" D) Inclined at 30°
Last Answer : The effect of stray magnetic fields on the actuating torque of a portable instrument is maximum when the operating field of the instrument and the stray fields are Parallel