InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 201. |
Which of the following does not exist ?A. Magnetic zero polesB. Magnetic monopolesC. Magnetic dipolesD. Magnetic tripoles |
| Answer» Correct Answer - B | |
| 202. |
Liquid oxygen remains suspended between two pole faces of a magnet because it isA. diamagneticB. antiferromagneticC. ferromagneticD. paramagnetic |
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Answer» Correct Answer - D Liquid oxygen has a light blue colous and is highly paramagnetic. The atomic magnetic dipoles align with an external magnetic field. This effect occure due to quantum mechanical spin as well as electron orbital angular momentum. When suspended between two pole faces of a magnet it acquries feeble magnetism hence remains suspended. |
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| 203. |
Which of the following can have negative value ?A. `chi`B. `mu_(r)`C. `mu_(0)`D. `mu_(r)` and `chi` both |
| Answer» Correct Answer - A | |
| 204. |
Which of the following properties is present in all the substances ?A. FerromagnetismB. ParamagnetismC. DiamagnetismD. None of these |
| Answer» Correct Answer - C | |
| 205. |
Magnetic susceptibility of the following type does not depend upon temperatureA. Diamagnetic substanceB. Ferromagnetic substanceC. Paramagnetic substanceD. Super conductors |
| Answer» Correct Answer - A | |
| 206. |
The magnitude of the equatorial magnetic field due to a bar magnet of length 2 cm at a distance of 1lm from its mid-point is (magnetic moment of the bar magnet is 0.60 A m)A. `5.0xx10^(-5)` TB. `6.0xx10^(-8)` TC. `7.0xx10^(-7)` TD. `8.0xx10^(-8)` T |
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Answer» Correct Answer - B Magnetic field of equatorial point is `B_(E)=(mu_(0)m)/(4pir^(3))` Here, `=(mu_(0))/(4pi)=10^(-7), r` = 1 m and `m` = 0.60 A `m^(2)` `therefore" "B_(E)=(10^(-7)xx0.60)/((1)^(3))=6.0xx10^(-8)` T |
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| 207. |
The dimension of Curie constant is given byA. `M^(-1) L^(-1) T^(2) A^(2) K`B. `K`C. `M L T^(-2) A^(-2) K^(-1)`D. `M T^(-2) A^(2) K` |
| Answer» Correct Answer - A | |
| 208. |
The dimension of pole strength of solenoid per unit current through it can be represented asA. `M^(0) L^(-1) T^(0) A `B. `M^(0) L^(0) T^(0) A`C. `M^(0) L^(+1) T^(0) A^(0)`D. `M^(0) LT^(0) A^(-1)` |
| Answer» Correct Answer - C | |
| 209. |
Liquid oxygen remains suspended between two pole faces of a magnet because it isA. Anti ferromagneticB. FerromagneticC. ParamagneticD. Diamagnetic |
| Answer» Correct Answer - C | |
| 210. |
STATEMENT-1 :Diamagnetic effects are present in all materials . and STATEMENT-2 : External magnetic field can develop some dipole moment in each atom due to electromagnetic induction .A. Statement-1 is True , Statement-2 is True , Statement-2 is a correct explanation for Statement-1B. Statement-1 is True , Statement-2 is True , Statement-2 is NOT a correct explanation for Statement- 1C. Statement-1 is True , Statement-2 is FalseD. Statement-1 is False , Statement-2 is True |
| Answer» Correct Answer - A | |
| 211. |
Which of the following is incorrect ?A. As you move from geographic north-pole to south-pole , the magnetic inclination changesB. As you move from geographic north-pole to south-pole , the magnetic declination always changesC. True angle of dip can be found without placing the compass in the magnetic meridianD. The value of true dip at a place is always greater than the value of apparent dip at that place |
| Answer» Correct Answer - D | |
| 212. |
Which of the following statement is incorrect about hysteresis?A. This effect is common to all ferromagnetic substanceB. The hysteresis loop area is proportional to the thermal energy developed per unit volume of the materialC. The hysteresis loop area is independent of the thermal energy developed per unit volume of the materialD. The shape of the hysteresis loop is characteristic of the material |
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Answer» Correct Answer - C The energy lost per unit volume of a substance complete cycle of magnetisation is equal to the area of the hysteresis loop. |
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| 213. |
What is the magnitude of axial field due to a bar magnet of length 3 cm at a distance of 75 cm from its mid-point if its magnetic moment is 0.6 Am?A. 0.013`mu` TB. 0.113 `mu` TC. 0.213 `mu` TD. 0.313 `mu` T |
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Answer» Correct Answer - C Here, `m`= 0.6 A `m^(2)`, `r`=75 cm = 0.75 m `B_("axial")=(mu_(0))/(4pi)*((2m)/(r^(3)))=10^(-7)xx(2xx0.6)/((0.75)^(3))` `therefore" "B_("axial")=2.13xx10^(-7)` T = 0.213`mu`T. |
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| 214. |
The magnetic flux has the dimensionA. `M L^(2) T A^(-1)`B. `M L^(2) T^(-1) A^(-1)`C. `M T^(-2) A^(-1)`D. `M L^(2) T^(-2) A^(-1)` |
| Answer» Correct Answer - D | |
| 215. |
What is the magnitude of the equational and axial fields due to a bar magnet of length 8.0 cm at a distance of 50 cm from its mid-point ? The magnetic moment of the bar magnet is `0.40 A m^(2)`, |
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Answer» From Eq. `B_(E) = (mu_(0)m)/(4pi r^(3)) = (10^(-7) xx 0.4)/((0.5)^(3)) = (10^(-7) xx 0.4)/(0.125) = 3.2 xx 10^(-7) T` From Eq., `B_(A) = (mu_(0) 2m)/(4 pi r^(3)) = 6.4 xx 10^(-7) T`. |
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| 216. |
Which of the following is incorrect ?A. Diamagnetic property is because of the induced dipole moment due to change in the orbital motion of electrons in atoms by the applied fieldB. Paramagnetic property is primarily because of the unpaired electrons present in the atoms and moleculesC. Ferromagnetism arises due to spin-orbit interaction , due to which material gets divided into small regions called domainsD. None of these |
| Answer» Correct Answer - D | |
| 217. |
Which of the following materials would weaken the magnetic field strength at a point if introduced ?A. CuB. AlC. Liquid `O_(2)`D. Co |
| Answer» Correct Answer - A | |
| 218. |
A short magnet of magnetic induction fields `B_(1),B_(2),B_(3)` values on this line at points which are at distance 30cm, 60cm and 90cm respectivley from the centre of the magnet isA. `27:3:37:1`B. `37.3:1:27`C. `27:8:3.37`D. `1:2:3` |
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Answer» Correct Answer - A We know that the magnetic field induciton at a point, `" " B=mu_(0)/(4pi)(M)/(r^(3))` According to question `B_(1):B_(2):B_(3)=(1)/(0.3)^(3):(1)/(0.6)^(3):(1)/(0.9)^(3)` 27:3:37:1 |
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| 219. |
The permeability of a specimen decreases drastically above certain temperature . The specimen could beA. FerromagneticB. DiamagneticC. ParamagneticD. Non-magnetic |
| Answer» Correct Answer - A | |
| 220. |
A cylindrical rod magnet has a length of 5 cm and a diameter of 1 cm. It has a unifirm magnetisation of `5.30xx10^(3) Amp//m^(3)`. What its magnetic dipole moment?A. `1xx10^(-2)J//T`B. `2.08xx10^(-2)J//T`C. `3.08xx10^(-2)J//T`D. `1.52xx10^(-2)J//T` |
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Answer» Correct Answer - B Relation for dipole moment is, `M=IxxV`. Volume of the cylinder `V=pir^(2)l`, where r is the radius and `l` is the length of the cylinder. Then dipole moment `M=Ipir^(2)l=(5.30xx10^(3))xx22/7xx(0.5xx10^(-2))^(2)(5xx10^(-2))` `=2.08xx10^(-2)J//T` |
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| 221. |
The magnetic field due to a short magnet at a point in its axis at distance `X` cm from the middle of the magnet isA. `100` GaussB. `400` GaussC. `50` GaussD. `200` Gauss |
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Answer» Correct Answer - A Along the axis of magnet `B_(a)=(2M)/X^(3)=200` Gauss rArr `B_(a)=M/X^(3)=100` Gauss |
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| 222. |
A specimen of iron of permeability `8 xx 10^(-3)` weber/A m is placed in a magnetic field of strength 160 A/m . Magnetic induction in this iron isA. `0.8 Wb//m^(2)`B. `5 xx 10^(-5) Wb//m^(2)`C. `1.28 Wb//m^(2)`D. `20 xx 10^(3) Wb//m^(2)` |
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Answer» `B = mu H` `B = 8 xx 10^(-3) xx 160` `= 1.28 Wb//m^(2)` |
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| 223. |
Magnetic field intensity is defined asA. Magnetic moment per unit volumeB. Magnetic induction force acting acting on a unit magneticpoleC. Number of lines of lines of force crossing per unit areaD. Number of lines of force crossing per volume |
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Answer» Correct Answer - B Number of lines of lines of force passing through per unit area normally is intensity of magnetic field, hence option (c ) is incorrect. The correct option is (b). |
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| 224. |
`"Weber"//m^(2)` is equal toA. VoltB. HenryC. TeslaD. All of these |
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Answer» Correct Answer - C Magnetic flux `varphi=BAimpliesB=varphi/A="Weber"/m^(2)=Tesla` |
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| 225. |
The magnetic induction in air at a distance d from an isolated point pole of strenth m unit will beA. `m/d`B. `m/d^(2)`C. `md`D. `md^(2)` |
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Answer» Correct Answer - B `B=m/d^(2)` in C.G.S. system. |
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| 226. |
Dip circle can be used to determine the angle of dip at a place . Dip circle consists of a magnetic needle free to rotate in a vertical plane . The end points of the needle move over a vertical circular scale . This arrangement can rotate about vertical axis . The angle rotated about vertical axis can be read from a horizontal scale . The magnetic needle will stay in vertical position ifA. The dip circle is in geographic meridianB. The dip circle is in magnetic meridianC. The dip circle is perpendicular to the magnetic meridianD. The dip circle is perpendicular to the geographic meridian |
| Answer» Correct Answer - C | |
| 227. |
Dip circle can be used to determine the angle of dip at a place . Dip circle consists of a magnetic needle free to rotate in a vertical plane . The end points of the needle move over a vertical circular scale . This arrangement can rotate about vertical axis . The angle rotated about vertical axis can be read from a horizontal scale . If a dip circle is further rotated about vertical axis by `60^(@)` then the apparent dip at that position will beA. `tan^(-1) ((1)/(sqrt2))`B. `tan^(-1)(2)`C. `60^(@)`D. `tan^(-1)((2)/(sqrt3))` |
| Answer» Correct Answer - D | |
| 228. |
Dip circle can be used to determine the angle of dip at a place . Dip circle consists of a magnetic needle free to rotate in a vertical plane . The end points of the needle move over a vertical circular scale . This arrangement can rotate about vertical axis . The angle rotated about vertical axis can be read from a horizontal scale . If the dip circle is now rotated about vertical axis by `90^(@)` .Now the needle is at `60^(@)` from vertical . The angle of dip at that place isA. `30^(@)`B. `60^(@)`C. `90^(@)`D. `150^(@)` |
| Answer» Correct Answer - A | |
| 229. |
A ring of mean radius 15 cm has 3500 turns of wire wound on a ferromagnetic core of relative permeability 800. The magnetic field in the core for a magnetising current of 1.2 A isA. 2.48TB. 3.48TC. 4.48TD. 5.48T |
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Answer» Correct Answer - C `"Here", r=15cm=15xx10^(-2)m` `N=3500 "turns", I=1.2A, mu_(r)=800` Then number of turns/length (n) `(N)/(2pir)=(3500)/(2pixx15xx10^(-2))=4.48T` |
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| 230. |
A Rowland ring of mean radius 16 cm has 4000 turns of wire wound on a ferromagnetic core of relative permeability 800 . What is magnetic field in the core for a magnetising current of 1.2 A ? |
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Answer» `B = (mu_(0) mu_(r) 2"Ni")/(4 pi r)` ` B = (10^(-7) xx 800 xx 2 xx 4000 xx 1.2)/(16 xx 10^(2))` `B = (8 xx 2 xx 4 xx 1.2)/(16)` `B = 4.8 T` |
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| 231. |
A Rowland ring of mean radius 15 cm has 3500 turns of wire wound on a ferromagnetic core of relative permeability 800. What is the magnetic field B in the core for a magnetising current of 1.2 A? |
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Answer» Mean radius of a Rowland ring, `r=15cm=0.15m` Number of turns on a ferromagnetic core, `N=3500` Relative permeability of the core material, `mu_(r)=800` Magnetising current, `I=1.2A`. The magneic field is given by the relation: `B=(mu_(1)mu_(0)1N)/(2pir)` where, `mu_(0)=` permeabilityof free space=`4nxx10^(-7)Tm A^(-1)` `B=(800xx4pixx10^(-7)xx1.2xx3500)/(2pixx0.15)=4.48T` Therefore, the magnetic field in the core is 4.48T. |
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| 232. |
In tan A position two short bar magnets of magnetic moments in ratio of `sqrt3 : 1` are placed at same distance respectively . If the deflection produced for the first magnet be `60^(@)` then what will be deflection for second magnet ?A. `45^(@)`B. `60^(@)`C. `30^(@)`D. `90^(@)` |
| Answer» Correct Answer - A | |
| 233. |
A magnet of magnetic moment `2JT^(-1)` is aligned in the direction of magnetic field of `0.1T`. What is the net work done to bring the magnet normal to the magnrtic field?A. `0.1J`B. `0.2 J`C. `1 J`D. `2 J` |
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Answer» Correct Answer - B Work done in rotating in the magnetic in uniform magnetic field is given by `W=MB(cos theta_(1)-cos theta_(2))` `Here, theta_(1)=0^(@) and theta_(2)=90^(@)` `therefore " " W=2xx0.1(cos0^(@)-cos90^(@))` `=2xx0.1(1-0)=0.2J` |
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| 234. |
A magnet of magnetic moment M is rotated through `360^(@)` in a magnetic field H, the work done will beA. `MH`B. `2MH`C. `2piMH`D. Zero |
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Answer» Correct Answer - D `W=MB(costheta_(1)-costheta_(2)), theta_(1)=0^(@)` and `theta_(2)=360^(@)` `implies W=0` |
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| 235. |
Magnetic permeability is maximum forA. Diamagnetic substanceB. Paramagnetic substanceC. Ferromagnetic substanceD. All of these |
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Answer» Correct Answer - C Theory based |
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| 236. |
If a diamagnetic solution is poured into a U-tube and one aem of this U-tube placed between the poles of a strong magnet with the meniscus in a line with the field, then the level of the solution willA. RiseB. FallC. Oscillate slowlyD. Remains as such |
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Answer» Correct Answer - B Because, diamagnetic substance, moves from stronger magnetic field to weaker field. |
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| 237. |
A short bar magnet has a magnetic moment of `0*48JT^-1`. Give the direction and magnitude of the magnetic field produced by the magnet at a distance of `10cm` from the centre of the magnet on (i) the axis (ii) the equatorial line (normal bisector) of the magnet.A. `0.48xx10^(-4)` T along N-S directionB. `0.28xx10^(-4)` T along S-N directionC. `0.28xx10^(-4)` T along N-S directionD. `0.96xx10^(-4)` T along S-N direction |
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Answer» Correct Answer - D On the axis of the magnet `B=(mu_(0))/(4pi)*(2m)/(d^(3))` Here, `(mu_(0))/(4pi)=10^(-7)"A m"^(-2)` `" "m=0.48" J T"^(-1), d=10` cm = 0.1 m Then, `B=(10^(-7)xx2xx0.48)/((0.1)^(3))` `" "=0.96xx10^(-4)` T along S-N direction. |
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| 238. |
If toroid uses bismuth for its core, will the field in the core be (slightly) greater or (slightly) less than when the core is empty ? |
| Answer» As bismuth is diamagnetic, therefore, the field in the core will be slightly less than when the core is empty. | |
| 239. |
Magnetic lines form continuous closed loop. Why ? |
| Answer» Magnetic lines of force always starts from north pole and forming curved path, enter south pole and travel to north pole inside the magnet. Thus lines of force are forming closed loops. | |
| 240. |
The location of the north magnetic pole is a latitude ofA. `79.74^(@) N`B. `79.74^(@) S `C. `71. 8 ^(@) W`D. `108 . 22^(@)` E |
| Answer» Correct Answer - A | |
| 241. |
A line joining places of zero declination is calledA. Isogonic linesB. Isoclinic lines C. Agonic linesD. Aclinic lines |
| Answer» Correct Answer - C | |
| 242. |
Two magnets of equal magnetic moments M each are placed as shown in figure below . The resultant magnetic moment is M . Then value of `theta` is A. `theta = 60^(@)`B. `theta = 90^(@)`C. `theta - 45^(@)`D. `theta = 30^(@)` |
| Answer» Correct Answer - A | |
| 243. |
An electron moving around the nucleus with an angular momenturm l has a magnetic momentA. `(e)/(m)l`B. `(e)/(2m)l`C. `(2e)/(m)l`D. `(e)/(2pim)l` |
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Answer» Correct Answer - B An electron moving around the nucleus has a magnetic moment `mu` is iven by `mu=(e)/(2m)l` Where , l is the magnitude of the angluar momentum of the circulating electron around the nucleus. The smallest value of `mu` is called the bohr magneton `mu_(B)` and its value is `mu_(B)=9.27xx10^(24)JT^(-1).` |
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| 244. |
An example of a diamagnetic substance isA. AluminiumB. CopperC. IronD. Nickel |
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Answer» Correct Answer - B Theory based |
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| 245. |
Resultant force acting on a diamagentic material in a magnetic field is in direction |
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Answer» Correct Answer - A Resultant force acting on a diamagnetic material in a magnetic field is in direction from stronger to the weaker part of the magnet field. |
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| 246. |
Magnets cannot be made from which of the following substances?A. IronB. NickelC. CopperD. All of the above |
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Answer» Correct Answer - C Theory based |
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| 247. |
Core of electromagnets are made of ferromagnetic materials which haveA. low permeability and high retentivityB. high permeability and low retentivityC. low permeability and low retentivityD. high permeability and high retentivity |
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Answer» Correct Answer - B Core of electromagnets are made up of ferromagnetic material which has high permeability and how retentivity. |
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| 248. |
Core of electromagnets are made of ferromagnetic materials which haveA. low permeability and low retentivityB. high permeability and high retentivityC. high permeability and low retentivityD. low permeability and high retentivity. |
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Answer» Correct Answer - D Core of electromagnets are made of soft iron that is ferromagnetic material with high permeability and low retantivity. |
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| 249. |
The material suitable for making electromagnets should haveA. high retentivity and high corecivityB. low retentivity and low coerivityC. high retentivity and low coercivityD. low retenivity and high corecivity |
| Answer» Correct Answer - C | |
| 250. |
What is happens to the force between magnetic poles when their pole strenght and the distance between them both gets doubled ? |
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Answer» Correct Answer - B Let pole strength be `m_(1) and m_(2)` and distance between them is r, then force between magnetic poles, `Falpha (m_(1)m_(2))/(r^(2))` In second case, `F alpha ((2m_(1))(2m_(2)))/(2r^(2)), alpha=(m_(1)m_(2))/(r)` |
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