Description : When the electric current is passed through conducting solution, there is change in colour of the solution. This indicates a) chemical effect of current b) the heating effect of current c) the magnetic effect of current d) the lightning effect of current
Last Answer : a) chemical effect of current
Description : The effects due to electric current are: I. Magnetic effect II. Heating effect III. Luminous effect Application working on which effect can be used on AC as well as DC supply? a. I only b. II only c. II and III only d. I, II only
Last Answer : The effects due to electric current are: I. Magnetic effect II. Heating effect III. Luminous effect Application working on which effect can be used on AC as well as DC supply? a. I only b. II only c. II and III only d. I, II only
Description : Electric ovens using heating elements of _______________ can produce temperature upto 3000°C. (A) Nickel (B) Graphite (C) Chromium (D) Iron
Last Answer : Ans: C Chromium has high melting point.
Description : The primary function of an electric motor is to ___________. A. develop torque B. generate high voltages C. produce a magnetic field D. generate high electrical resistance
Last Answer : Answer: A
Description : In the heating process of the ________type a simple method of temperature control is possible by means of a special alloy which loses its magnetic properties at a particular high temperature and regains ... ) core type induction furnace (C) coreless induction furnace (D) high frequency eddy current
Last Answer : Ans: D Magnetic property of alloy changes with change of the temperature and Heat is produced due to eddy current = i2R and i α f2
Description : APPLICATION OF HEATING EFFECT OF ELECTRIC CURRENT
Last Answer : APPLICATION OF HEATING EFFECT OF ELECTRIC CURRENT: In an electric circuit, the unavoidable heating can increase the temperature of the components and alter their properties. Heating effect has many ... a fine heated platinum wire is used for cutting tissues much more efficiently than a knife.
Description : The resistance furnace produces heat by the (A) Electric arc struck between electrodes and the charge (B) Flow of current through a heating element (C) Combination of induced current and skin effect (D) None of these
Last Answer : (B) Flow of current through a heating element
Description : Heating Effect of Electric Current
Last Answer : Heating Effect of Electric Current
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 : Electric ovens using heating elements made of _________can produce a temperature up to 3000°C. (A) nickel (B) graphite (C) chromium (D) iron
Last Answer : Electric ovens using heating elements made of chromium can produce a temperature up to 3000°C.
Description : Flemings "Left hand Rule" is associated with the effect of – (1) Electric field on current (2) Magnetic field on magnet (3) Electric field on magnet (4) Magnetic Field on current
Last Answer : (4) Magnetic Field on current Explanation: Whenever, a current carrying conductor comes under a magnetic field, there will be force acting on the conductor and on the other hand, if a conductor ... conductor. In both of the phenomenon, there is a relation between magnetic field, current and force.
Description : Flemings “Left hand Rule” is associated with the effect of (1) Electric field on current (2) Magnetic field on magnet (3) Electric field on magnet (4) Magnetic Field on current
Last Answer : Magnetic Field on current
Description : Magnetic Effect of Electric Current
Last Answer : Magnetic effect of electric current. Field is effect or characteristics in space due to which an object experience a force. Field is a force without direct contact. The Imaginary lines of force ... iron junk etc. Effects of electric current are heating effect, magnetic effect and chemical effect.
Description : Magnetic keepers are used to protect magnets from : (1) Earth's magnetic field (2) effect of other magnets (3) self-demagnetization (4) demagnetization due to heating
Last Answer : (3) self-demagnetization Explanation: Magnets have a tendency to lose their magnetism when their poles are left bare. This is called selfdemagnetization. Magnets are, therefore, protected by keeping them in magnetic keepers.
Description : Magnetic keepers are used to protect magnets from : (1) Earth’s magnetic field (2) effect of other magnets (3) self-demagnetization (4) demagnetization due to heating
Last Answer : self-demagnetization
Description : An electric heating element supplied with 120 volts draws 15 amps. How much power will be consumed? A. 15 watts B. 45.57 watts C. 180 watts D. 1800 watts
Description : Out of the following methods of heating the one which is independent of supply frequency is (A) electric arc heating (B) induction heating (C) electric resistance heating (D) dielectric heating
Last Answer : (C) electric resistance heating
Description : Chemical Effect of Electric current
Last Answer : Chemical Effect of Electric current
Description : Particle nature of cathode rays is proved due to the fact that they (A) Travel in a straight line (B) Get deflected by magnetic electric field (C) Produce fluorescence (D) Heat the exposed material
Last Answer : Option B
Description : The method used to produce electron emission in most vacuum tubes is known as ____________. A. photoelectric emission B. secondary electric emission C. cold cathodic electric emission D. thermionic emission
Description : An electric toaster uses nichrome for its heating element. When a negligibly small current passes through it. It resistance at room temperature `(27.0
Last Answer : An electric toaster uses nichrome for its heating element. When a negligibly small current passes through it. ... range involved , `1.70xx10^-4C^-1`
Description : Why in electric motor or generator heating due to current involves dissipation of electrical energy?
Last Answer : In electric motor or generator heating due to current involves dissipation of electrical energy because as the current increases there will be I2R losses. More current flow means more the heat will be generated and as the temperature of conductor increase its resistance increases.
Description : Hysteresis in a direct current generator is indicated by _____________. A. arcing at the brushes B. pulsating terminal current C. heating of the armature core D. hunting and over control
Last Answer : Answer: C
Description : What power is consumed by a heating element using a current of 20 amperes at 120 volts? A. 20 watts B. 66.67 watts C. 720 watts D. 2400 watts
Description : What is the wattage of a heating element drawing a current of 30 amperes, at 120 volts? A. 30 watts B. 99.97 watts C. 360 watts D. 3600 watts
Description : Which of the following principle is used to produce low-temperatures'? (1) Super conductivity (2) Joule-Kelvin effect (3) Thermo-electric effect (4) Adiabatic demagnetization
Last Answer : (4) Adiabatic demagnetization Explanation: Magnetic refrigeration is a cooling technology based on the magnetocaloiic effect. This technique can be used to attain extremely low temperatures, as well as the ... of a suitable material is caused by exposing the material to a changing magnetic field.
Description : Which of the following principle is used to produce ‘low-temperatures’ ? (1) Super conductivity (2) Joule-Kelvin effect (3) Thermo-electric effect (4) Adiabatic demagneti-sation
Last Answer : Adiabatic demagneti-sation
Description : When two or more atoms are linked together the force holding them together is called a _____. a. charged particle b. chemical bond. c. electric attraction. d. magnetic bond.
Last Answer : b. chemical bond.
Description : With neat cross sectional constructional details,write effect of magnetic and electric field in magnetron
Last Answer : 1)When magnetic & electric fields act simultaneously upon the electron,its path can have any of a number of shapes dictated by the resistive strengths of the mutually perpendicular electric & ... happens because in practice the applied magnetic field is greatly in excess of the cutoff field.
Description : What is magnetic locking or cogging effect of induction motor?
Last Answer : In squirrel cage induction motor some times the rotor and stator care teeth or slots are comes face to face or parallel at stationary condition. If we are starting the motor at this condition the motor ... the rotor slot, such that there is no common factor between the rotor slot and stator slots.
Description : In low or standard frequency induction furnace, heat is produced by the (A) Combination of induced current and skin effect (B) Induction and resistance (C) Current flow through a heating element (D) None of these
Last Answer : (B) Induction and resistance
Description : Th effect or response produced by two or more chemicals are less than the sum of the effects or response that the chemical would produce individually is known as - (1) Antagonism (2) Independent (3) Additive (4) Synergism
Last Answer : (1) Antagonism Explanation: Synergy is the interaction of multiple elements in a system to produce an effect different from or greater than the sum of their individual effects. On the other hand, ... of two or more substances to produce an effect less than the sum of their individual effects.
Description : The effect or response produced by two or more chemicals are less than the sum of the effects or response that the chemical would produce individually is known as (1) Antagonism (2) Independent (3) Additive (4) Synergism
Last Answer : Antagonism
Description : A marine cartilaginous fish that can produce electric current is
Last Answer : A marine cartilaginous fish that can produce electric current is A. Pristis B. Torpedo C. Trygon D. Scoliodon
Description : Find the minimum number of cells required to produce an electric current of 1.5 A through a resistance of `30 Omega`. Given that the emf of each cell
Last Answer : Find the minimum number of cells required to produce an electric current of 1.5 A through a resistance ... .5 V and internal resistance `1.0 Omega`.
Description : What type of magnets are produce by running electric current through a soft iron core?
Last Answer : electromagnet
Description : Give reason: Stationary coil and stationary magnet cannot produce induced electric current.
Last Answer : An emf is induced in the coil only when there is relative motion between the coil and the magnet.
Description : A marine cartilaginous fish that can produce electric current is (a) Pristis (b) Torpedo (c) Trygon (d) Scoliodon.
Last Answer : b) Torpedo
Description : After turning on the fluorescent lamp shown in the illustration, you note that the ends of the tube alternately glow and becomce dark without illuminating the center. The most obable cause for ... the lamp D. component 'B' contacts are opening and closing thus prohibiting sufficient current flow
Description : The illustration shows a fluorescent light fixture. The ends of the lamp alternately glow and become dark, but the tube will not light. The most probable cause is that ____________. EL-0081 ... start the lamp D. component 'B' contacts are opening and closing thus prohibiting sufficient current flow
Description : The rotor slots of a repulsion-type motor are generally skewed (placed nonparallel to the rotor axis) to _________. A. produce a constant starting torque B. permit a greater air gap with the starter C. permit a smaller air gap with the starter D. reduce eddy current losses
Description : In a 15 HP induction-type motor with a cage rotor, the current required at standstill to produce starting torque is approximately ____________. A. half the full load current B. equal to the full load current C. five times the full load current D. ten to twenty times the full load current
Description : The purpose of amortisseur windings in a synchronous motor is to ______________. A. reduce eddy current losses B. produce a higher power factor C. provide a means for starting D. eliminate arcing between the stator and the rotor
Description : Amortisseur windings are installed in a synchronous motor to _____________. A. reduce eddy current losses B. produce a higher power factor C. provide a means for starting D. eliminate arcing between the stator and the rotor
Description : During start-up of the circuit shown in the illustration, it is noted that the ends of component 'C' alternately glow and become dark without the tube illuminating. The most probable cause ... start the lamp D. component 'B' contacts are opening and closing thus prohibiting sufficient current flow
Description : As a result of electric current a magnetic field is created around it , from whose test can it be realized ?
Last Answer : An electric current creates a magnetic field around it , as can be seen from Hans Christian Werstead's experiments.
Description : A large metal sheet carries an electric current along its surface. Current per unit length is `lambda` . Magnetic field near the metal sheet is.
Last Answer : A large metal sheet carries an electric current along its surface. Current per unit length is `lambda` . Magnetic ... (2pi)` D. `(mu_(0))/(2pilambda)`
Description : A current carrying conductor is associated with – (1) a magnetic field (2) an electric field (3) an electro-magnetic field (4) an electrostatic field
Last Answer : (3) an electro-magnetic field Explanation: A current carrying conductor, such as a metal wire, will produce a magnetic field around it because of the motion of charge within the wire itself. This motion produces or sets up a magnetic field around the wire in the form of concentric circles.
Description : If we reverse the direction of electric current, then the direction of magnetic field will be A. reversed B. remains same C. becomes tangent D. becomes norma
Last Answer : reversed
Description : F = BIL can only be used if the magnetic field and electric current are A. at right angles to each other B. in same direction C. anti-parallel to each other D. anti-perpendicular to each other
Last Answer : at right angles to each other