The use of permanent magnets is. not made in
(a) magnetoes
(6) energy meters
(c) transformers
(d) loud-speakers

1 Answer

Answer :

(c) transformers

Related questions

Description : Permanent magnets are generally made of

Last Answer : Alnico alloys

Description : The materials having low retentivity are suitable for making (a) weak magnets (b) temporary magnets (c) permanent magnets (d) none of the above

Last Answer : (b) temporary magnets

Description : Permanent magnets can be made from A. Aluminum B. Lead C. Zinc D. Cobalt

Last Answer : ANSWER: D

Description : Pick out the wrong statement. (A) A ferromagnetic material becomes paramagnetic above the 'Curie temperature' (B) Permanent magnets are made of hard materials, whereas electromagnets require soft ... hysterisis loss and coercive forces (D) Tungsten steel and alnico are not hard magnetic materials

Last Answer : Option D

Description : Permanent magnets are made of high carbon steel and (A) 15% of cobalt (B) 20% of cobalt (C) 35% of cobalt (D) 45% of cobalt

Last Answer : Answer: Option D

Description : Permanent magnets are made of (A) soft magnetic materials. (B) hard magnetic materials. (C) semi conductors. (D) super conductors.

Last Answer : (B) hard magnetic materials.

Description : Permanent magnets are normally made of?

Last Answer : Permanent magnets are normally made of alnico alloys.

Description : X-rays can penetrate several ____ into a solid matter. a) millimeters b) meters c) centimeters d) kilometers

Last Answer : c) centimeters

Description : The resistance of a few meters of wire conductor in closed electrical circuit is?

Last Answer : The resistance of a few meters of wire conductor in closed electrical circuit is practically zero.

Description : The most suitable metal for making permanent magnet is a) Iron b) Steel c) Silver d) Copper

Last Answer : a) Iron

Description : Magnetic flux linked with a coil can be changed by using an: a. Permanent magnet b.Bar magnet c. Electromagnet d. Horseshoe magnet

Last Answer : b.Bar magne

Description : In motor a permanent magnet provides: a. Electric field b. electric flux c. magnetic field d. gravitational field

Last Answer : d. gravitational field

Description : What permanent magnets can affect?

Last Answer : Both permanent magnets and electromagnets. -Apex

Description : Hard magnetic materials are used for making (A) Permanent magnets. (B) Temporary magnets. (C) Conductors. (D) Insulator.

Last Answer : (A) Permanent magnets.

Description : Hard ferrites are used for making (A) Transformer cores. (B) Electrical machinery. (C) High frequency equipment. (D) Light weight permanent magnets.

Last Answer : (D) Light weight permanent magnets.

Description : The materials used for permanent magnets should have

Last Answer : The materials used for permanent magnets should have high retentivity, high coercivity

Description : Hard steel is suitable for making permanent magnets because?

Last Answer : Hard steel is suitable for making permanent magnets because it has good residual magnetism.

Description : Those materials are well suited for making permanent magnets which have _____ retentivity and _______ coercivity.

Last Answer : Those materials are well suited for making permanent magnets which have high retentivity and high coercivity.

Description : can turning the sound up too loud damage my surround sound speakers?

Last Answer : If you turn the sound up too high on your stereo system, you can damage the surround sound speakers. Your speakers have a maximum amount of power they can handle from the amplifiers, and if you turn the volume up too high, you are giving the speakers too much power.

Description : Are there any laws on how loud my car speakers can be?

Last Answer : Every city has sound volume regulations for car stereos and they are usually very strict.

Description : What is usually used for displaying information at public places? a) Monitors b) Overhead Projections c) Monitors and Overhead Projections d) Touch Screen Kiosks e) Loud Speakers

Last Answer : b) Overhead Projections

Last Answer : No. of 20 watts loudspeakers permitted to connect an 250 watt amplifier are 12.

Last Answer : Loud Speakers are always connected in parallel on Both of them.

Description : The amount of energy required to completely remove an electron from the first Bohr orbit is a) 13.6 MeV b) 13.6 eV c) 1.36 MeV d) 1.36 eV

Last Answer : b) 13.6 eV

Description : Problem on electrical power and energy 6

Last Answer : Problem on electrical power and energy 6

Description : In Helium-neon Laser, in meta stable state, helium is located at the energy level: a) 20.66 eV b) 20.77 eV c) 20.61 eV d) 20.71 eV

Last Answer : c) 20.61 eV

Description : An atomic energy state in which more atoms are in the lower energy state E1 than in the excited state E2, is known as a) population inversion b) normal population c) stimulated population d) atomic population

Last Answer : b) normal population

Description : The emission in which the atom emits a photon of energy hf = E2 – E1 , in any arbitrary direction is a) Spontaneous emission b) stimulated emission c) induced emission d) both a & c

Last Answer : d) both a & c

Description : The total energy of electron in the Bohr orbit is given by the formula, E = a) - ke2 /2r b) - ke2 /2r2 c) - k 2 e/2r d) - ke2 /r

Last Answer : a) - ke2 /2r

Description : The X-rays emitted in inner shell transitions are called _____ as their energy depends upon the type of target material. a) gamma rays b) special X-rays c) Characteristic X-rays d) continuous X-rays

Last Answer : c) Characteristic X-rays

Description : By the transition of inner shell electrons in heavy atoms, high energy photons are emitted which are a) gamma rays b) X-rays c) radio waves d) photon rays

Last Answer : b) X-rays

Description : The energy required to completely remove an electron from the first Bohr orbit is called a) excited energy b) ionization energy c) accelerated energy d) orbital energy

Last Answer : b) ionization energy

Description : The minimum energy required to eject an electron from a metal surface is called a) Intensity b) Threshold frequency c) Work function d) Photo energy

Last Answer : c) Work function

Description : Which one of the following quantities is conserved in pair production? a) Energy b) Charge c) Linear momentum d) All

Last Answer : d) All

Description : If energy of incident photon is greater than the rest mass energy of electron positron pair, the surplus energy is shared by the pair as, a) Potential energy b) Thermal energy c) Electronic energy d) Kinetic energy

Last Answer : d) Kinetic energy

Description : The phenomena of pair production occurs only when the energy of incident photon is least equal a) 10.2 MeV b) 1.02 MeV c) 1.02 eV d) 0.102 MeV

Last Answer : b) 1.02 MeV

Description : The relativistic energy ‘E’ is equivalent to relativistic mass given by a) Ec2 b) 2 c E c) c E d) E c

Last Answer : b) 2 c E

Description : The energy required to magnetize and demagnetize is called a) Saturation b) Retentivity c) Coercivity d) Hysteresis loss

Last Answer : d) Hysteresis loss

Description : Which of the following converts electric energy into mechanical energy: a. Transformer b. DC generator c. Motor d. AC generator

Last Answer : d. AC generato

Description : The loss of energy over each A.C cycle magnetization and demagnetization of transformer, is called: a. Magnetization loss b. Hysteresis loss c. Demagnetization loss d. energy loss

Last Answer : c. Demagnetization loss

Description : Energy stored per unit volume inside the solenoid is called: a. Energy density b. Charge Density c. Mass density d. Volume charge density

Last Answer : energy density is correct

Description : An ideal transformer always obeys the law of conservation of........: a. energy b. momentum c. charge d. Flux

Last Answer : b. momentum

Description : A magnetic field acts on a charged particles so as to change its: a. speed b. energy c. direction of motion d. all of these

Last Answer : Only direction of motion will change ...it means velocity will change but speed same

Description : If magnetic field is doubled then magnetic energy density becomes: a. Four times b. Two times c. Three times d. Six times

Last Answer : c. Three times

Description : Alternating current generator converts.......... energy into electrical energy? a. mechanical energy b. chemical energy c. solar energy d. potential energy

Last Answer : a. mechanical energy

Description : The energy density of an inductor is: a. B 2 / 2 μ2 b. B/ 2 μ c. B/ 2 μ2 d. B 2 / 2 μ

Last Answer : c. B/ 2 μ2

Description : Lenz’s law is in accordance with the law of conservation of: a. momentum b. Angular momentum c. charge d. energy

Last Answer : a. momentum

Description : Which of the following quantities change when a proton moves at right angles to a magnetic field? a) Momentum b) Energy c) Speed d) All of these

Last Answer : a) Momentum

Description : A proton moves in a uniform magnetic field in a circular path of radius R. If the energy of proton is doubled then the new radius becomes a) R √2 b) 2R c) R 2 d) √2 R

Last Answer : d) √2 R