{"id":35859,"date":"2022-11-25T22:21:37","date_gmt":"2022-11-25T16:51:37","guid":{"rendered":"https:\/\/tsboardsolutions.com\/?p=35859"},"modified":"2022-11-26T10:13:41","modified_gmt":"2022-11-26T04:43:41","slug":"ts-inter-2nd-year-physics-study-material-chapter-8","status":"publish","type":"post","link":"https:\/\/tsboardsolutions.com\/ts-inter-2nd-year-physics-study-material-chapter-8\/","title":{"rendered":"TS Inter 2nd Year Physics Study Material Chapter 8 Magnetism and Matter"},"content":{"rendered":"

Telangana TSBIE\u00a0TS Inter 2nd Year Physics Study Material<\/a> 8th Lesson Magnetism and Matter Textbook Questions and Answers.<\/p>\n

TS Inter 2nd Year Physics Study Material 8th Lesson Magnetism and Matter<\/h2>\n

Very Short Answer Type Questions<\/span><\/p>\n

Question 1.
\nA magnetic dipole placed in a magnetic field experiences a net force. What can you say about the nature of the magnetic field?
\nAnswer:
\nFor a magnetic dipole placed in a magnetic field, some net force is experienced It implies that force on the two poles of dipole is not equal.<\/p>\n

This will happen only when magnetic dipole is in non-uniform magnetic field.<\/p>\n

Question 2.
\nThere is no question in text book. [TS Mar. 19, 17, May 14]
\nQuestion 3.
\nWhat happens to compass needles at the Earth’s poles? [TS Mar. 19, 17, May 14]
\nAnswer:
\nWhen a compass is taken to earth poles say north pole then south pole of compass will adhere to north pole. It will align it self along magnetic meridian line.<\/p>\n

Similarly when it is taken to south pole then north pole of compass is attracted by south pole and it will align itself along magnetic meridian line.<\/p>\n

Question 4.
\nWhat do you understand by the ‘magnetisation’ of a sample?
\nAnswer:
\nMagnetisation (T) :
\nIt is the ratio of magnetic moment per unit volume.<\/p>\n

I = (\\(\\frac{M}{V}\\)) where M = the magnetic moments and V = volume of the given material.<\/p>\n

Magnetic intensity is a vector, dimensions L-1<\/sup> A.
\nUnit : Ampere\/metre : Am-1<\/sup><\/p>\n

Question 5.
\nWhat is the magnetic moment associated with a solenoid?
\nAnswer:
\nMagnetic moment associated with a solenoid (M) = nIA. Where
\nn = Number of turns in solenoid;
\nI = Current through it;
\nA = Area vector<\/p>\n

\"TS<\/p>\n

Question 6.
\nWhat are the units of magnetic moment, magnetic induction and magnetic field? [AP Mar. 16. May 17, 16; TS Mar. 16]
\nAnswer:
\n1. Magnetic moment m is a vector. Unit A-m\u00b2, dimensions L-2<\/sup> A.
\n2. Magnetic induction (B) and magnetic field (B) are used with same meaning. Magnetic induction B is a vector.
\nUnit: Tesla (T), Dimension : MT-2<\/sup>A-1<\/sup>.<\/p>\n

Question 7.
\nMagnetic lines form continuous closed loops. Why? [AP Mar. ’19, ’16, May ’18; TS May ’18, Mar. ’17]
\nAnswer:
\nIn magnetism magnetic monopole (single pole) is not existing. The simple possible way is to take a magnetic dipole. So the path a free magnetic needle or compass starts from north pole and terminates at south pole forms a loop.<\/p>\n

Hence magnetic field lines are always closed loops.<\/p>\n

Question 8.
\nDefine magnetic declination. [TS Mar. 18, May 18, 17, 16; AP Mar. 18, 14, May 17, 16]
\nAnswer:
\nMagnetic declination (D) :
\nThe magnetic meridian at a place makes some angle (D) with true geographic north and south direction.<\/p>\n

The angle between true geographic north to the north shown by magnetic compass is called “magnetic declination or simply declinations (D).”
\n\"TS<\/p>\n

Question 9.
\nDefine magnetic inclination or angle of dip. [AP Mar. ’17, ’15; TS Mar. ’15]
\nAnswer:
\nMagnetic inclination or angle of dip (I) :
\nIt is the angle of total magnetic field BE at a given place with the surface of earth.
\n(OR)
\nThe angle between horizontal to earth’s surface and net magnetic field of earth BE at that point.<\/p>\n

Question 10.
\nClassify the following materials with regard to magnetism: Manganese, Cobalt, Nickel, Bismuth, Oxygen, Copper. [AP Mar. 19. 18. 17, 16, 15; TS Mar. 16. 15]
\nAnswer:
\nManganese : Paramagnetic substance
\nCobalt : Ferromagnetic substance
\nNickel : Ferromagnetic substance
\nBismuth : Diamagnetic substance
\nOxygen : Paramagnetic substance
\nCopper : Diamagnetic substance<\/p>\n

Question 11.
\nIn the magnetic meridian of a certain place, the horizontal component of the earth\u2019s magnetic field is 0.26 G and the dip angle is 60\u00b0. What Is the magnetic field of the earth at this location?
\nAnswer:
\nGiven HE = 0.26 G; Dip angle = 60
\nBut Dip angle = \\(\\frac{H_E}{B_E}\\) = cos \u03b8 \u21d2 BE<\/sub> = HE<\/sub> cos \u03b8
\n\u2234 Magnetic field of earth = 0.26 \u00d7 cos 60\u00b0 = 2 \u00d7 0.26 = 0.52 G<\/p>\n

Question 12.
\nDefine Magnetisation of a sample. What is its SI unit?
\nAnswer:
\nMagnetisation (I) : It is the ratio of net magnetic moment per unit volume.
\nI = \\(\\frac{m_{net}}{V}\\) where mnet<\/sub> = the vectorial sum of magnetic moments of atoms in bulk material and V is volume of the given material.
\nMagnetic intensity is a vector, dimensions L-1<\/sup> A.
\nUnit: Ampere\/metre : A m-1<\/sup>.<\/p>\n

\"TS<\/p>\n

Question 13.
\nDefine Magnetic susceptibility. Mention its unit. [AP Mar. ’15]
\nAnswer:
\nMagnetic susceptibility (\u03c7) :
\nIt is a measure for the response of magnetic materials to an external field.
\n\"TS
\nIt is a dimensionless quantity.<\/p>\n

Short Answer Questions<\/span><\/p>\n

Question 1.
\nWhat are Ferromagnetic materials? Give examples. What happens to a ferromagnetic material at Curie temperature?
\nAnswer:
\nFerromagnetism:<\/p>\n

    \n
  1. These substances are strongly attracted by magnets.<\/li>\n
  2. The susceptibility (\u03c7) is +ve and very large.<\/li>\n
  3. Individual atoms of these substances will spontaneously align in a common direction over a small volume called domain.<\/li>\n
  4. Size of domain is nearly 1 mm\u00b3 or a domain may contain nearly 1011<\/sup> atoms.<\/li>\n
  5. In these substances, magnetic field lines are very crowded.<\/li>\n
  6. Every ferromagnetic substance will transform into paramagnetic substance at a temperature called Curie Temperature (Tc<\/sub>).
    \nEx: Manganese, Iron, Cobalt, Nickel etc.<\/li>\n<\/ol>\n

    Effect of temperature on Ferromagnetic substances :
    \nWhen ferromagnetic substances are heated upto Curie temperature, they will be converted into paramagnetic substances.<\/p>\n

    Question 2.
    \nDerive an expression for the axial field of a solenoid of radius “r”, containing “n” turns per unit length and carrying current “I”.
    \nAnswer:
    \nThe behaviour of a magnetic dipole and a current carrying solenoid are similar.<\/p>\n

    Let a solenoid of radius ‘a’ and length 2l contains n turns and a current ‘I’ is passed through it.<\/p>\n

    Magnetic moment of solenoid (M) = nlA.<\/p>\n

    Consider a circular element of thickness dx of solenoid at a distance x from its centre. Choose any point ‘P’ on the axis of solenoid at a distance ‘r’ from centre of the axis.
    \n\"TS<\/p>\n

    Magnetic field at point P
    \n\"TS
    \nThis is similar to magnetic field at any point on the axial line of magnetic dipole.<\/p>\n

    Question 3.
    \nThe force between two magnet poles separated by a distance ‘d’ in air is ‘F. At what distance between them does the force become doubled?
    \nAnswer:
    \nForce between two magnetic poles F = \\(\\frac{\\mu_0}{4 \\pi} \\frac{\\mathrm{m_1m_2}}{\\mathrm{d^2}}\\)
    \n\"TS
    \n\"\"
    \nWhen separation between the poles is reduced by \u221a2 times their force between them is doubled.<\/p>\n

    Question 4.
    \nCompare the properties of para, dia and ferromagnetic substances. [TS & AP June ’15]
    \nAnswer:<\/p>\n\n\n\n\n\n\n\n
    Paramagnetic substances<\/td>\nDiamagnetic substances<\/td>\nFerromagnetic substances<\/td>\n<\/tr>\n
    1. Feebly attracted by magnets.<\/td>\n1. Repelled by magnets.<\/td>\n1. Strongly attract by magnets.<\/td>\n<\/tr>\n
    2. Susceptibility is +ve and nearly equals to one.
    \n\u03c7 = i<\/td>\n    		2. Susceptibility is -ve and less than one.
    \n\u03c7 < 1<\/td>\n    		2. Susceptibility is + ve and large.
    \n\u03c7 > > 1<\/td>\n<\/tr>\n
    3. In a magnetic filed they move from weak field to strong field.<\/td>\n3. They move from strong field to weak field.<\/td>\n3. They move from weak field to strong field.<\/td>\n<\/tr>\n
    4. They have individual atomic magnetic moments but total magnetic moment is zero.
    \nEx: Aluminium, sodium etc.<\/td>\n    		4. Individual atomic magnetic moment is zero.
    \nEx: Bismuth, copper, lead.<\/td>\n    		4. They have individual atomic magnetic moments. These atoms will form domains. Magnetic moment of all atoms in adomain is in same direction.
    \nEx: Iron, cobalt, nickel.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    \"TS<\/p>\n

    Question 5.
    \nExplain the elements of the Earth’s magnetic field and draw a sketch showing the relationship between the vertical component, horizontal component and angle of dip.
    \nAnswer:
    \nEarth’s magnetism :
    \nThe magnetic field of earth is believed to arise due to electrical currents produced by convective motion of metallic fluids in outer core of earth. This effect is also known as the “dynamo effect”.<\/p>\n