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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.
| 51. |
consider the following statement A and B , and select the correct choice A: Repulsion is a sure test of magnetism. (B) : Magnetic induction precedes attration.A. Only A is trueB. Only B is trueC. Both are trueD. Both are false |
| Answer» Correct Answer - C | |
| 52. |
The values of the apparent angles of dip in two planes at right angles to each other are `30^(@)` and `45^(@)`. Then the true value of the angle of dip at the place is |
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Answer» Correct Answer - `26.6 ^(@)` |
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| 53. |
The magnetic moment of atomic neon isA. ZeroB. `muB//2`C. `muB`D. `3muB//2` |
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Answer» Correct Answer - A |
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| 54. |
The magnetic moment of atomic neon isA. zeroB. `muB//2`C. `mu B `D. `3 mu B//2 ` |
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Answer» Correct Answer - A Since , neone (Ne) atom is diamagnetic, therefore its net magnetic moment is zero . |
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| 55. |
Relative permeability of iron is 5500, then its magnetic susceptibility will beA. `5500xx10^(7)`B. `5500xx10^(-7)`C. `5501`D. `5499` |
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Answer» Correct Answer - D `chi=mu_(r)-1` |
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| 56. |
The relative permeability (µr ) for air is ……… |
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Answer» The relative permeability (µr ) for air is one. |
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| 57. |
Relative permeability of iron is 5500. Its magnetic susceptibility is-(a) 5501 (b) 5500 x 10-7 (c) 5500 x 107 (d) 5499 |
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Answer» (d) 5499 µr = 1 + x ⇒ x = µr -1 = 5500 – 1 = 5499 |
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| 58. |
The relative permeability of diamagnetic material is ……… |
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Answer» The relative permeability of diamagnetic material is less than one. |
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| 59. |
The relative permeability of a diamagnetic material is- (a) greater than unity (b) less than unity (c) equal to unity(d) negative |
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Answer» (b) less than unity |
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| 60. |
Assertion : For a perfectly diamagnetic substance permeability is always one. Reason : The ability of a material of permit the passage of magnetic lines of force through it is called magnetic permeability.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertionC. f assertion is true but reason is false.D. If assertion is false but reason is true |
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Answer» Correct Answer - D |
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| 61. |
In which type of material the magnetic susceptibility does not depend on temperature?A. Ferrite substancesB. Ferromagnetic substancesC. Diamagnetic substancesD. Paramagnetic substances |
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Answer» Correct Answer - C |
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| 62. |
Assertion : For a perfectly diamagnetic substance permeability is always one. Reason : The ability of a material of permit the passage of magnetic lines of force through it is called magnetic permeability.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertionC. f assertion is true but reason is false.D. If assertion is false but reason is true |
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Answer» Correct Answer - D |
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| 63. |
Assertion : The susceptibility of diamagnetic materials does not depend upon temperature. Reason : Every atom of a diamagnetic material is not a complete magnet in itself.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertionC. if assertion is true but reason is false.D. If the assertion and reason both are false |
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Answer» Correct Answer - C |
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| 64. |
In which type of material the magnetic susceptibility does not depend on temperature?A. DiamagneticB. ParamagneticC. FerromagneticD. Ferrite |
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Answer» Correct Answer - A |
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| 65. |
A short magnetic needle is pivoted in a uniform magnetic field of induction `1T`. Now, simultaneously another magnetic field of induction `sqrt3T` is applied at right angles to the first field, the needle deflects through an angle `theta` where its value isA. `30^(@)`B. `45^(@)`C. `90^(@)`D. `60^(@)` |
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Answer» Correct Answer - D `B=B_(H)tantheta` |
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| 66. |
A diamagnetic material in a magnetic field movesA. perpendicular to the fieldB. from weaker to the stronger parts of the fieldC. from stronger to the weaker parts of the fieldD. None of the above |
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Answer» Correct Answer - C |
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| 67. |
Two bar magnets having same geometry with magnetic moments M and 2M, are firstly placed in such a way what their similar poles are same side then its time period of oscillation is `T_1`. Now the polarity of one of the magnet is reversed then time period of oscillation will be:-A. `T_(1)ltT_(2)`B. `T_(1)gtT_(2)`C. `T_(1)=T_(2)`D. `T_(2)=oo` |
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Answer» Correct Answer - A |
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| 68. |
Three magnets of same length but moments `M,2M` and `3M` are arranged in the form of an equilateral triangle with oppositive poles nearer, the resultnat magnetic moment of the arrangement isA. `6M`B. `zero`C. `sqrt3M`D. `(sqrt3)/(2)M` |
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Answer» Correct Answer - C `M_(R )sqrt(M_(1)^(2)+M_(2)^(2)+2M_(1)M_(2)costheta)` |
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| 69. |
Two short magnets placed along the same axis with their like poles facing each other repel each other with a force which varies inversely asA. Square of the distanceB. Cube of the distanceC. DistanceD. Fourth power of the distance |
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Answer» Correct Answer - D |
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| 70. |
Two short bar magnets with magnetic moments `8Am^(2)` and `27Am^(2)` are placed `35cm` apart along their common axial line with their like poles facing each other. The neutral point isA. midway between themB. `21 cm` from weaker magnetC. `14 cm` from weaker magnetD. `27 cm` from weaker magnet |
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Answer» Correct Answer - C form weaker pole `x=(d)/(((M_(2))/(M_(1)))^(1//3)+1)` |
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| 71. |
A paramagnetic sample shows a net magnetisation of `8Am^-1` when placed in an external magnetic field of `0*6T` at a temperature of `4K`. When the same sample is placed in an external magnetic field of `0*2T` at a temperature of `16K`, the magnetisation will beA. `(32)/(3)Am^(-1)`B. `(2)/(3)Am^(-1)`C. `6 Am^(-1)`D. `2.4 Am^(-1)` |
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Answer» Correct Answer - B As curie law explains, we can deduce a formula for the relation between magnetic field induction, tempreature and magnetisation. `i.e.,` `I("magnetisation")oo(B("magnetic field induction"))/(t("tempreture in kelvin"))` `rArr (I_(2))/(I_(1))=(B_(2))/(B_(1))xx(t_(1))/(t_(2))` Let us suppose, here `I_(1)=8 Am^(_1)B_(1)=0.6T, t_(1)=4K` `B_(2)=0.2T,t_(2)=16K` `rArr (0.2)/(0.6)xx(4)/(16)=(I_(2))/(8)` `rArr` `I_(2)=8xx(1)/(12)=(2)/(3)Am^(-1)` |
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| 72. |
Two north poles each of pole strength `8Am` are placed at corners `A` and `C` of a square `ABCD`. The pole that should be placed at `B` to make `D` as null point isA. North pole of pole strength `8sqrt2Am`B. North pole of pole strength `16sqrt2Am`C. south pole of pole strength `16sqrt2Am`D. south pole of pole strength `8sqrt2Am` |
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Answer» Correct Answer - C `F_(n et)=0` |
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| 73. |
Two identical north poles each of strength `m` are kept at vertices `A` and `B` of an equilateral triangle `AbC` of side a. The mutual force of repulsion between them has a magnitude of `F`. The magnitude of magnetude at `C` isA. `F//m`B. `F//sqrt3m`C. `F//3m`D. `sqrt3F//m` |
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Answer» Correct Answer - D `B=(mu_(0))/(4pi)(m)/(d^(2)),F=(mu_(0))/(4pi)(m_(1)m_(2))/(d^(2))` |
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| 74. |
At two coners `A` and `B` of an equilateral triangle `ABC`, a souith and north pole each of strength `30An` are placed. If the side of the triangle is `1m`. The magnetic induction at `C` isA. `3xx10^(-6)T`B. `4xx10^(-6)T`C. `8xx10^(6-)T`D. `2xx10^(-6)T` |
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Answer» Correct Answer - A `B=(mu_(0))/(4pi)(m)/(d^(2))` |
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| 75. |
Two north poles each of pole strength `m` and a south pole of pole strength `m` are placed at the three corners of an equilateral triangle of side a. The intensity of magnetic induction field strength at the centre of the triangle isA. `(mu_(0))/(4pi)(m)/(a^(2))`B. `(mu_(0))/(4pi)(6m)/(a^(2))`C. `(mu_(0))/(4pi)(9m)/(a^(2))`D. `(mu_(0))/(4pi)(m)/(2a^(2))` |
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Answer» Correct Answer - B `B_(res)=2B "where"B=(mu_(0))/(4pi)(m)/((a//sqrt3)^(2))` |
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| 76. |
Assertion: Basic difference between an electric line and magnetic line of force is that former is discontinuous and the latter is continuous or endless. Reason: No electric lines of force exist inside a charged body but magnetic lines do exist inside a magnet.A. Both `A` and `R` are true and `R` is the correct explanation of `A`.B. Both `A` and `R` are true and `R` is not correct explanation of `A`.C. `A` is true, But `R` is falseD. `A` is false, But `R` is true |
| Answer» Correct Answer - A | |
| 77. |
Assertion (A): It is not necessary that every magnet has one north pole and one south pole. Reason (R ): It is a basic fact that magnetic poles occur in pairsA. Both `A` and `R` are true and `R` is the correct explanation of `A`.B. Both `A` and `R` are true and `R` is not correct explanation of `A`.C. `A` is true, But `R` is falseD. `A` is false, But `R` is true |
| Answer» Correct Answer - D | |
| 78. |
A large magnet is broken into two pieces so that their lengths are in the ratio 2:1. The pole strengths of the two pieces will have the ratio(A) 2 : 1 (B) 1 :2 (C) 4 : 1(D) 1 : 1 |
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Answer» Correct option is: (A) 2 : 1 |
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| 79. |
Two like poles of strengths `m_(1)` and `m_(2)` are at far distance apart. The energy repuired to bring them `r_(0)` distance apart isA. `(mu_(0)/(4pi)(m_(1)m_(2))/(r_(0)))`B. `(mu_(0)/(8pi)(m_(1)m_(2))/(r_(0)))`C. `(mu_(0)/(16pi)(m_(1)m_(2))/(r_(0)))`D. `(mu_(0)/(2pi)(m_(1)m_(2))/(r_(0)))` |
| Answer» Correct Answer - A | |
| 80. |
Two similar magnetic poles, having pole strengths in the ratio `1:2` are placed `1m` apart. Find the point where a unit pole experiences no net force due to the two polese. |
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Answer» Correct Answer - `0.414` m from first pole |
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| 81. |
If the magnetic flux is expressed in weber, then magnetiv induction can be expressed inA. `Weber//m`B. `Weber//m`C. `Weber-m`D. `Weber-m` |
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Answer» Correct Answer - A |
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| 82. |
What are the SI units of magnetic field induction or magnetic flux density?A. TeslaB. `Weber//metre^(2)`C. Newton/ampere - metreD. All of the above |
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Answer» Correct Answer - D |
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| 83. |
The most appropriate magnetization M versus magnetising field H curve for a paramagnetic substance is A. AB. BC. CD. D |
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Answer» Correct Answer - A |
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| 84. |
On applying an external magnetic field , to a ferromagnetic substance domainsA. align in the direction of magnetic fieldB. align in the direction opposite to magnetic fieldC. remain unaffectedD. None of the above |
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Answer» Correct Answer - A On applying magnetic field, domains of ferromagnetic substance align themselves in the direction of magnetic field. |
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| 85. |
The magnetic moment of a bar magnet is `0.256amp.m^(2)`. Its pole strength is `400` milli amp. `m`. It is cut into two equal pieces and these two pieces are arranged at right angles to each other with their unlike poles in contact (or like poles in contact). The resultant magnetic moment of the system isA. `sqrt2xx256xx10^(-3) Am^(2)`B. `250xx10^(-3)Am^(2)`C. `(256)/(sqrt2)xx10^(-3)Am^(2)`D. `(128)/(sqrt2)xx10^(-3)Am^(2)` |
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Answer» Correct Answer - C `M_(1)=M_(2)=(M)/(2)` `M_(n et)=sqrt(M_(1)^(2)+M_(2)^(2))` |
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| 86. |
Two magnetic poles of pole strength `324 milli amp.m.` and `400 milli amp m` are kept at a distance of `10cm` in air. The null point will be at a distance of ……`cm,`on the line joining the two poles, from the weak pole if they are like poles.A. `4.73`B. `5`C. `6.2`D. `5.27` |
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Answer» Correct Answer - A `(m^(1))/(x^(2))=(m_(2))/((d-x)^(2))` |
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| 87. |
A magnet has a dimensions of `25cmX10cmX5cm` and pole strength of `200` milli ampm The intensity of magnetisation due to it isA. `6.25A//m`B. `62.5A//m`C. `40A//m`D. `4A//m` |
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Answer» Correct Answer - C `I=(M)/(V)=(m)/(a)` |
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| 88. |
A "bar" magnet is at right angles to a uniform magnetic field. The couple acting on the magnet is to be one fourth by rotating it from the position. The angle of rotation isA. `Sin^(-1)(0.25)`B. `90^(@)-Sin^(-1)(0.25)`C. `Cos^(-1)(0.25)`D. `90^(@)-Cos^(-1)(0.25)` |
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Answer» Correct Answer - B `C=MB sin theta` |
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| 89. |
A "bar" magnet of length `16 cm` has a pole strength of `500` milli amp.`m`. The angle at which it should be placed to the direction of external magnetic field of induction `2.5` gauses so that it may experience a torque of `sqrt(3)xx10^(-5)Nm` isA. `pi`B. `pi//2`C. `pi//3`D. `pi//6` |
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Answer» Correct Answer - C `C=MB sin theta` |
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| 90. |
Needles `N_(1) , N_(2), and N_(3)` are made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively . A magnet when brought close to them willA. attract all three of themB. attract `N_(1)` and `N_(2)` strongly but repel `N_(3)` weaklyC. attract `N_(1)` strongly, `N_(2)` weakly and repel `N_(3)` weaklyD. attract `N_(1)` strongly, but repel `N_(2),N_(3)` weakly |
| Answer» Correct Answer - C | |
| 91. |
Needles `N_(1) , N_(2), and N_(3)` are made of a ferromagnetic, a paramagnetic and a diamagnetic substance respectively . A magnet when brought close to them willA. attract `N_(1) and N_(2) ` strongly but repel `N_(3)`B. attract `N_(1)` strongly , `N_(2) ` weakly and repel `N_(3) ` weaklyC. attract `N_(1) ` strongly , but repel `N_2 and N_3 ` weaklyD. attract all three of them . |
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Answer» Correct Answer - B Ferromagnetic substance have strong tendency to get magnetised ( induced magnetic moment ) in the same direction as that of applied magnetic field , so magnet attracts `N_(1)` strongly . Paramagnetic substances get weekly magnetised ( magnetic moment induced in small ) in the same direction as that of applied magnetic field , so magnet attracts `N_(2)` weakly . Diamagnetic substance also get weakly magnetised when placed in an external magnetic field but in opposite direction and hence , `N_3` is weakly repelled by magnet . |
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| 92. |
What type of magnet used in Mangle train? |
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Answer» An extremely powerful electromagnet is used in Mangle train. |
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| 93. |
............. is the ore of iron which is the strongest natural magnet. (a) Iron oxide (b) Iron sulphide (c) Ferrite (d) Columbine |
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Answer» (a) Iron oxide |
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| 94. |
Mention the properties of a magnet. |
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Answer» Repulsive: 1. Attractive property a magnet always attracts materials like iron, cobalt and nickel 2. Property another property of a magnet that like poles repel each other i.e., a north pole repels another north pole and a south pole repels another south pole. 3. Directive property the property of a magnet, by which it aligns itself along the geographic north-south direction, when it is freely suspended, is known as the directive property of a magnet. |
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| 95. |
Mention the three types of iron ores. |
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Answer» Hematite (69% of Iron), Magnetite (72.4% of Iron) and Side-rite (48.2% of Iron). Magnetite is an oxide ore of iron with the formula Fe 304. Among these ores, Magnetite has more magnetic property. |
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| 96. |
Give some examples of artificial magnets. |
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Answer» Bar magnets, U-shaped magnets, horseshoe magnets, cylindrical magnets, disc magnets, ring magnets and electromagnets are some examples of artificial magnets. |
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| 97. |
How artificial magnets are produced? |
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Answer» Artificial magnets are produced by stroking a magnetic material with magnetite or with other artificial magnets. |
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| 98. |
Name the strongest and the most powerful magnets on the Earth. |
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Answer» Neodymium magnets. |
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| 99. |
List out the uses of magnets in day-to-day life. |
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Answer» 1. In ancient times, the magnet in the form of ‘direction stone’ helped seamen to find the directions during a voyage. 2. Nowadays, magnets are used to generate electricity in dynamos. 3. Electromagnets are used in our day-to-day life. 4. They are used in electric bells and electric motors. 5. They are used in loudspeakers and microphones. 6. An extremely powerful electromagnet is used in the fast moving Maglev train to remain floating above the tracks. 7. In industries, magnetic conveyor belts are used to sort out magnetic substances from scraps mixed with non-magnetic substances. 8. Magnets are used in computer in its storing devices such as hard disks. 9. In banks, the magnets enable the computers to read the MICR numbers printed on a cheque. 10. The tip of the screw drivers are made slightly magnetic so that the screws remain attached to the tip. 11. At hospitals, extremely strong electro magnets are used in the MRI (Magnetic Resonance Imaging) to scan the specified internal organ. |
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| 100. |
Mention any two uses of magnets. |
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Answer» 1. In ancient times, the magnet in the form of ‘direction stone helped seamen to find the directions during a voyage. 2. Magnets are used in computer in its storing devices such as hard disks. |
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