{"id":13988,"date":"2024-03-22T12:21:17","date_gmt":"2024-03-22T06:51:17","guid":{"rendered":"https:\/\/tsboardsolutions.in\/?p=13988"},"modified":"2024-03-25T17:01:52","modified_gmt":"2024-03-25T11:31:52","slug":"ts-10th-class-physical-science-important-questions-chapter-10","status":"publish","type":"post","link":"https:\/\/tsboardsolutions.in\/ts-10th-class-physical-science-important-questions-chapter-10\/","title":{"rendered":"TS 10th Class Physical Science Important Questions Chapter 10 Electromagnetism"},"content":{"rendered":"
These TS 10th Class Physics Chapter Wise Important Questions<\/a> Chapter 10 Electromagnetism will help the students to improve their time and approach.<\/p>\n 1 Mark Questions<\/span><\/p>\n Question 1. Question 2. Question 3. Question 4. Question 5. <\/p>\n Question 6. Question 7. Question 8. Question 9. Question 10. Question 11. Question 12. Question 13. Question 14. <\/p>\n Question 15. Question 16. Question 17. Question 18. Question 19. Question 20. Question 21. Question 22. Question 23. Question 24. <\/p>\n Question 25. Question 26. Question 27. Question 28. Question 29. Question 30. Question 31. Question 32. Question 33. <\/p>\n Question 34. Question 35. Question 36. Question 37. Question 38. Question 39. Question 40. Question 41. Question 42. Question 43. Question 44. Question 45. <\/p>\n Question 46. Question 47. Question 48. Question 49. Question 50. Question 51. Question 52. Question 53. Question 54. Question 55. Question 56. Question 57. Question 58. Question 59. <\/p>\n Question 60. Question 61. Question 62. 2 Marks Questions<\/span><\/p>\n Question 1. Question 2. Question 3. Question 4. Question 5. <\/p>\n Question 6. Question 7. Question 8. <\/p>\n Question 9. 4 Marks Questions<\/span><\/p>\n Question 1. Question 2. Question 3. <\/p>\n Question 4. Question 5. Question 6. ii) When a bar magnet is withdrawn from inside the coil, again induced current flows through the coil due to the phenomenon of electromagnetic induction. In this case, the direction of induced current Is opposite to the direction of the current In case (i) as shown In figure (b).<\/p>\n iii) When the bar magnet is held stationary inside the coil, there is no change in magnetic field around the coil. Hence, no Induced current flows through the coil. Therefore, galvanometer shows no deflection as shown in figure (c).<\/p>\n <\/p>\n Question 7. W = FS Question 8. Question 9. (iv) What is the net force acting on the rectangular coil? Solved Problems<\/span><\/p>\n Question 1. Question 2. Question 3. <\/p>\n Question 4. Question 5. Question 6. Question 7. <\/p>\n Question 8. Do You Know?<\/span><\/p>\n The relation between direction of induced current, magnetic field and force can also be explained by Fleming’s left-hand rule. Stretch the. left-hand thumb, middle finger and forefinger \u00a1n such a way that they are mutually perpendicular to each other. The forefinger indicates the direction of magnetic field, the middle finger indicates the direction of current and thumb indicates direction of force. By using the Flemings left-hand rule we can explain the working of electric motor. (Page 224)<\/p>\n Do You Know? (Non-Textual)<\/span><\/p>\n 1. Hans Christian Oersted (1777 – 1851): Oersted recognized the significance of what he had Just done. Earlier, It was believed that electricity and magnetism were two different unconnected sciences. Oersted had demonstrated that they were Interconnected. Through this observation he showed that electricity and magnetism were related phenomena. Some scientists, influenced by this experiment, continued to work in the modem field of \u201celectromagnetism\u201d.<\/p>\n Their research resulted In several new scientific theories and various vital Inventions like the dynamo and the electric motor. With this a new technology prospered, leading to inventions such as radio, television, and fiber optics. The unit of magnetic field strength is named Oersted in his honour. Oersted was made a foreign member of \u201cRoyal Swedish Academy of Sciences in 1822.<\/p>\n 2. Michael Faraday: 3. George Simon Ohm (1787 – 1854): <\/p>\n 4. You might have seen that, during security check, people are made to walk through a large upright coil of wire which produces a weak AC (alternating) magnetic field. If we are carrying any significant quantities of iron, the magnetic flux linked with the large coil changes and the induced current generated in coil triggers an alarm.<\/p>\n","protected":false},"excerpt":{"rendered":" These TS 10th Class Physics Chapter Wise Important Questions Chapter 10 Electromagnetism will help the students to improve their time and approach. TS 10th Class Physical Science Important Questions Chapter 10 Electromagnetism 1 Mark Questions Question 1. What is electromagnetic induction? Answer: Mechanical energy can be converted Into electrical energy by moving a magnet inside … Read more<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/tsboardsolutions.in\/wp-json\/wp\/v2\/posts\/13988"}],"collection":[{"href":"https:\/\/tsboardsolutions.in\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tsboardsolutions.in\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tsboardsolutions.in\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/tsboardsolutions.in\/wp-json\/wp\/v2\/comments?post=13988"}],"version-history":[{"count":4,"href":"https:\/\/tsboardsolutions.in\/wp-json\/wp\/v2\/posts\/13988\/revisions"}],"predecessor-version":[{"id":14061,"href":"https:\/\/tsboardsolutions.in\/wp-json\/wp\/v2\/posts\/13988\/revisions\/14061"}],"wp:attachment":[{"href":"https:\/\/tsboardsolutions.in\/wp-json\/wp\/v2\/media?parent=13988"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tsboardsolutions.in\/wp-json\/wp\/v2\/categories?post=13988"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tsboardsolutions.in\/wp-json\/wp\/v2\/tags?post=13988"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}TS 10th Class Physical Science Important Questions Chapter 10 Electromagnetism<\/h2>\n
\nWhat is electromagnetic induction?
\nAnswer:
\nMechanical energy can be converted Into electrical energy by moving a magnet inside a coil.<\/p>\n
\nMention two uses of solenoid.
\nAnswer:
\nIt is used in electric bells, fans and motors.<\/p>\n
\nMention applications of electromagnetic Induction.
\nAnswer:
\nIt is used in devices which convert mechanical energy Into electrical energy.<\/p>\n
\nWhat is Maxwells right-hand screw rule?
\nAnswer:
\nThe direction of current is the direction in which the tip of the screw advances and direction of ration of the screw gives the direction of magnetic lines of force.<\/p>\n
\nWhere are the electromagnets used?
\nAnswer:
\nIn electric generators and televisions.<\/p>\n
\nWhat is electromagnet?
\nAnswer:
\nWhen current carrying conductor is wind over a magnetic material like soft Iron it gets magnetized.<\/p>\n
\nWhat are different types of power stations?
\nAnswer:
\nElectrical energy is produced in different power stations from mechanical energy of water, heat energy, and nuclear energy.<\/p>\n
\nWhat is the frequency of the AC. supplied in your house?
\nAnswer:
\nIt is approximately 50 Hz.<\/p>\n
\nWhat type of current Is generated in electric power station?
\nAnswer:
\nAlternating current.<\/p>\n
\nWhich instruments detect small currents?
\nAnswer:
\nGalvanometer.<\/p>\n
\nWhat is a transformer?
\nAnswer:
\nIt Is a device which increases or decreases the voltage.<\/p>\n
\nWhat is the relation between tesla and ampere meter?
\nAnswer:
\n1 Tesla = 1 NA-1<\/sup> m-1<\/sup>.<\/p>\n
\nIf a copper rod carries a direct current, then where will the magnetic field in the conductor?
\nAnswer:
\nIt will be both inside and outside the rod.<\/p>\n
\nWho proposed that a magnetic field is present in a current-carrying wire?
\nAnswer:
\nHans Christian Oersted proved that electricity and magnetism were related phenomena and also proved that a current-carrying wire possesses magnetic field.<\/p>\n
\nWhen a magnetic compass is kept near a current-carrying wire, what happens? Why?
\nAnswer:
\nWhen a magnetic compass is kept under a current-carrying wire the needle of compass deflects. This deflection is due to the magnetic field, possessed by current-carrying wire.<\/p>\n
\nHow is a magnetic field characterized?
\nAnswer:
\nThe magnetic field exists in the region surrounding a bar magnet and is characterized by Its strength and direction.<\/p>\n
\nWhat is the direction of magnetic field lines?
\nAnswer:
\nMagnetic field lines start from North pole of bar magnet and end at South pole. These are Imaginary lines.<\/p>\n
\nWhat is the use of magnetic field lines?
\nAnswer:
\nMagnetic field lines help us<\/p>\n\n
\nWhy the magnetic field drawn is non-unIform?
\nAnswer:
\nThe magnetic field drawn with the help of magnetic field lines is non-uniform because the strength and direction both change from point to point.<\/p>\n
\nWhen will be the magnetic field uniform?
\nAnswer:
\nThe magnetic field will be uniform if both strength and direction are constant throughout the field.<\/p>\n
\nDefine magnetic flux. Mention its S.I. units.
\nAnswer:
\nThe number of magnetic lines passing through the plane of area \u2018A\u2019 perpendicular to the field is called magnetic flux, denoted by 4 the S.J. unit of magnetic flux is weber.<\/p>\n
\nWhat Is magnetic flux density?
\nAnswer:
\nThe magnetic flux through unit area, which Is perpendicular to the magnetic field is known as magnetic flux density (B) or magnetic field induction.
\nB = \\(\\frac{\\Phi}{A} \\) The unit of (B) is \u201cWeber \/m2<\/sup> or \u201cTesla.<\/p>\n
\nWrite the formula for magnetic flux passing through an area A., with an angle q.
\nAnswer:
\nThe flux through the plane of area A, with an angle \u03b8, is given by \u03a6 = BA cos \u03b8.<\/p>\n
\nWhat Is the flux through the plane taken parallel to the field?
\nAnswer:
\nThe flux passes parallel to the field. Then \u03b8 = 0\u00b0
\n\u2234 \u03a6 =BA cos\u03b8 = BA cos 00<\/sup>\u21d2 \u03a6 = BA<\/p>\n
\nWhat do you conclude about magnetic field lines after conducting experiment with solenoids?
\nAnswer:
\nMagnetic field lines are closed loops.<\/p>\n
\nCalculate the force experienced by a charge moving in a magnetic field and perpendicular to the field?
\n
\nAnswer:
\nLet the charge q move with a velocity \u2018y\u2019 perpendicular to the magnetic field \u2018B\u2019. The value of magnetic force on the moving charge can be found experimentally as
\nF = qvB.<\/p>\n
\nWhat is the magnetic force on moving charge when there is an angle q between the directions of field \u2018B\u2019 and velocity \u2018V\u2019?
\nAnswer:
\nWhen there is an angle between direction of field and velocity, the magnetic force experienced by charge is given by
\nF = qvB sin \u03b8<\/p>\n
\nWhat is the magnetic force on the charge moving parallel to a magnetic field?
\nAnswer:
\nWhen charge moves parallel to the magnetic field the value of O becomes 0.
\nF = qvB sin \u03b8 = qvB sin 0\u00b0 = O
\nThus the charge experiences no force.<\/p>\n
\nWhat is the direction of magnetic force acting on a moving charge?
\nAnswer:
\nKeep your right-hand fingers along the direction of velocity F of moving charge and next curl your fingers towards the direction of magnetic field, then the thumb gives the H direction of magnetic force.
\n<\/p>\n
\nWhat is the direction of force acting on a negative charge moving in a field?
\nAnswer:
\nFirst find the direction of force acting on a positive charge moving In a field, using right-hand rule, and then reverse its direction. This new direction is the direction of force acting on the negative charge.<\/p>\n
\nWrite the Faraday\u2019s law of electromagnetic induction.
\nAnswer:
\nWhenever there is a continuous change of magnetic flux linked with a closed coil, a current is generated in the coil.<\/p>\n
\nWrite Lenzs law.
\nAnswer:
\nLenz\u2019s law states that \u201cthe Induced current will appear in such a direction that it opposes the changes in the flux In the coil\u201d.<\/p>\n
\nHow did a metal detector work?
\nAnswer:
\nDuring security check, people are made to walk through a large upright coil of wire which produces a weak A.C. magnetic field. If we are carrying any significant quantities of Iron, the magnetic flux linked with the large coil changes and the Induced current generated in coil triggers an alarm.<\/p>\n
\nWhat Is the principle of generator? (AS 1)
\nAnswer:
\nGenerator works on the principle of electromagnetic induction. It converts mechanical energy into electrical energy.<\/p>\n
\nWhat Is the difference between AC generator and DC generator?
\nAnswer:<\/p>\n\n
\nWhat are the characteristics of AC current?
\nAnswer:<\/p>\n\n
\nHow would you demonstrate the presence of an induced emf in the absence of a Galvanometer?
\nAnswer:
\nReplace the galvanometer by a small bulb, such as the one we find in a small torch light. The relative motion between the coil and magnet will cause the bulb to glow and thus demonstrate the presence of an induced current.<\/p>\n
\nOn what factors the magnetic induction at the center of the coil depends?
\nAnswer:
\nIt depends on current, number of turns, and radius of the coil.<\/p>\n
\nName the Instrument on which Ampere\u2019s law Is used.
\nAnswer:
\nTangent gaivanometer.<\/p>\n
\nWhich is more dangerous AC or DC?
\nAnswer:
\nAC is more dangerous.<\/p>\n
\nIn DC motor what type of magnetic field is produced by concave cylindrical magnets?
\nAnswer:
\nRadial<\/p>\n
\nWhat Is the use of galvanoscope?
\nAnswer:
\nIt detects the flow of current. It acts as current detector.<\/p>\n
\nState two serious hazards of electricity.
\nAnswer:<\/p>\n\n
\nWhy earthing of electrical appliances is recommended?
\nAnswer:
\nTo protect the user from any accidental electrical shock caused due to leakage of current.<\/p>\n
\nWhy Is a spark produced at the place of short circuit? Why Is the spark is of white colour?
\nAnswer:
\nThe resistance of circuit decreases and a sudden flow of large current heats up the live wire and vaporizes the metal. This causes spark. The metal of wire becomes white hot and naturally emits white light.<\/p>\n
\nIs the magnetic field formed \u00a1n a solenoid uniform or non-uniform?
\nAnswer:
\nIt is non-uniform.<\/p>\n
\nIs an electromagnetic field a vector or a scalar?
\nAnswer:
\nIt is a vector quantity.<\/p>\n
\nIn an electric bell which is attracted towards electromagnet?
\nAnswer:
\nArmature.<\/p>\n
\nIf the strength of the electric current increases, does the magnetic field Increase or decrease?
\nAnswer:
\nThe magnetic field also increases.<\/p>\n
\nIf the current \u00a1n the coil Is in an anti-clockwise direction then what would be the face of the coil?
\nAnswer:
\nIt behaves as north pole.<\/p>\n
\nIf the current In the coil is in clockwise direction then what would be the face of the coil?
\nAnswer:
\nIt behaves as south pole.<\/p>\n
\nWhat Is the shape of magnetic lines due to straight current-carrying conductor?
\nAnswer:
\nThey are concentric circles.<\/p>\n
\nState two ways by which speed or rotation of rotation of electric motor can be Increased.
\nAnswer:<\/p>\n\n
\nWhat happens If an Iron piece is dropped between two poles of strong magnet?
\nAnswer:
\nEddy current Is produced in it. These eddy currents oppose the motion of the piece of Iron. So It falls as it is moving through a viscous iiquid.<\/p>\n
\nIn what form the energy \u00a1n a current-carrying coil is stored?
\nAnswer:
\nIt is stored In the form of magnetic field.<\/p>\n
\nWhat is Solenoid?
\nAnswer:
\nA solenoid is a long wire wound In a close-packed helix.<\/p>\n
\nWhat Is the pattern of field lines Inside a solenoid around when current-carrying solenoid?
\nAnswer:
\nParallel to each other.<\/p>\n
\nList any two properties of magnetic field lines.
\nAnswer:<\/p>\n\n
\nWhy does the picture appear distorted when the bar magnet is brought close to the screen of a television?
\nAnswer:
\nPicture on a television screen is due to motion of the electrons reaching the screen. These electrons are affected by magnetic field of bar magnet.<\/p>\n
\nWhat is meant by electromagnetic induction?
\nAnswer:
\nWhenever there Is continuous change of magnetic flux linked with a closed coil, current is generated in the coil Is called electromagnetic induction.<\/p>\n
\nWhat is the use of slip ring In AC motor?
\nAnswer:
\nUses of slip rings: Slip rings are used to change the direction of current in the coil continuously.<\/p>\n
\nCorrect the diagram according to Lenz law and draw It again.
\nAnswer:
\n<\/p>\n
\nHow can we find the direction of magnetic field due to straight wire carrying Current?
\nAnswer:
\nThe direction of magnetic field due to straight wire carrying current can be determined by right-hand thumb rule.
\n
\nIf you grab the current-carrying wire with your right hand, In such a way that thumb is In the direction of current, then the curled fingers show the direction of magnetic field.<\/p>\n
\nHow can we find the direction of magnetic field due to coil or solenoid, carrying current?
\nAnswer:
\nThe direction of the field due to coil or solenoid carrying B current can be determined by using right-hand rule. When you curl your right-hand fingers in the N direction of current, thumb gives the direction of magnetic field.\u201d
\n<\/p>\n
\nExplain the working of induction stove.
\nAnswer:<\/p>\n\n
\nHow does the tape of a tape recorder reproduce voice?
\nAnswer:<\/p>\n\n
\nWhat is the direction of magnetic force when velocity of charge is perpendicular to the magnetic field?
\n(Or)
\nState Right-hand rule with a labelled diagram.
\nAnswer:
\nIf the forefinger points towards the direction of velocity of charge or current, middle finger points to the direction of the field (B), then thumb gives direction of force when three fingers are stretched in sud a way that they are perpendicular to each other.
\n
\nThis rule is applicable to positive charges.<\/p>\n
\nCurrent is flowing in a wire as shown In figure. Consider a square frame near to It. If suddenly current is stopped in wire then what is the direction of induced current In square frame?
\nAnswer:
\nAccording to right-hand thumb rule, the magnetic field is into the plane of the book. Suddenly current is stopped means magnetic field is decreasing. According to Lenz\u2019s law to oppose it in the square frame the induced current generates in clockwise direction ( S-Pole) and magnetic field is Into the paper.
\n
\n<\/p>\n
\nWhich energy we get from an electric motor? Write two daily life applications of the electric motor?
\nAnswer:
\nMechanical energy.
\nApplications of electric motor:<\/p>\n\n
\nTake a long cylindrical copper tube. Hold It so that It Is perpendicular to the horizontal. A stone and a bar magnet are left freely, so that bar magnet passes through the tube and stone outside the tube. Which one reaches the earth first? Guess why It Is so? Give proper reasons.
\nAnswer:<\/p>\n\n
\nWhy do not two Magnetic lines of force Intersect each other?
\nAnswer:
\nThe tangent at any point on a magnetic field line gives the direction of Magnetic field at that point. 1f two magnetic field lines across each other than at that point of intersection, there will be two tangents. Hence there will be two directions of the magnetic field at the point of intersection. This Is not possible. Hence no two magnetic field lines can intersect each other Let r be the radius of the circular path. We know that centripetal force = mv2<\/sup>\/r<\/p>\n
\nA coil is hung as shown in the figure. A bar magnet with north pole facing the coil Is moved perpendicularly.
\na) How does the magnetic flux passing through the coil change?
\nb) State the direction of the flow of the current induced in the coil, keeping the direction of bar magnet In views.
\nc) Draw the diagrams showing the magnetic field formed due to bar magnet at the surface of the coil and the magnetic field formed due to Induced current.
\nd) Explain the reason for induced current.
\n
\nAnswer:
\na) A bar magnet with north pole facing the coil is moved perpendicularly, the magnetic flux is increases when passing through the coil.
\nb) The direction of the flow of the current induced in the coil, keeping the direction of bar magnet is anti-clockwise due to north pole.
\n
\nc) \u03a6 = 0
\nPlane of coil Is parallel to \u2018B’
\nb) Electromagnetic induction is the reason for induced current.<\/p>\n
\nConductor of length moves perpendicular to its length with the speed V. Length of the conductor is perpendicular to the magnetic field of the conductor. Let us assume that electrons could move freely in the conductor and the charge of an electron is \u2018e\u2019.
\na) What is the magnetic force acting on electron in the conductor.
\nb) In which direction does the above force act.
\nc) What effect does this force have on motion of electrons.
\n
\nAnswer:
\na) Magnetic field acting on the electron inside the conductor is = F\u03c0<\/sub> = e(V \u00d7B) = BeV
\nThis field acts from P to Q.
\nb) Consider in the field P and Q are ends of a conductor. Q acts as negative end and \u2018P\u2019 acts as positive end then flow passes from P to Q means downwards.
\nc) The force on electrons shows an effect creates a potential difference at the ends of the roads.
\n\u2234 BeV=eE \u21d2 E=BV
\n<\/p>\n
\nHow can we apply conservation of energy for electromagnetic induction I?
\nAnswer:<\/p>\n\n
\n
\nDraw the diagram of magnetic field lines when current passes through the solenoid and label the parts.
\nAnswer:
\n<\/p>\n
\nDraw the magnetic field lines to form around the bar magnet.
\nAnswer:
\n<\/p>\n
\nA coil of Insulated copper wire Is connected to a galvanometer. What will happen If a bar magnet is (i) pushed into the coil, (ii) withdrawn from inside the coil, (iii) held stationary Inside the coil?
\nAnswer:
\n
\ni) When a bar magnet is pushed into the coil, Induced current flows through the coil due to the phenomenon of electromagnetic induction. This Induced current is indicated by the deflection of the needle of the galvanometer as shown in figure (a).<\/p>\n
\nDerive Faraday\u2019s law of Induction from law of conservation of energy.
\nAnswer:<\/p>\n\n
\nSubstitute (1) W = FS<\/sub>= BIls \u2192 (2)
\n\u0394\u03a6 = Bls \u2192 (3)
\nFrom (2) and (3)
\nW = (\u0394\u03a6)I
\nLet us divide both sides by \u0394t
\n\\(\\frac{W}{\\Delta t}=I \\frac{\\Delta \\Phi}{\\Delta t} \\) \u2192 (4)
\n\u03b5 = \\(\\frac{\\Delta \\Phi}{\\Delta t}\\)
\nElectric power, P = \u03b5I \u2192 (5)
\nElectric power P = I\\(\\frac{\\Delta \\Phi}{\\Delta t}\\)
\n
\nDivide (2) by \u0394t
\n\\(\\frac{W}{\\Delta t}=\\frac{F s}{\\Delta t}=\\frac{B I l s}{\\Delta t}\\) ……………… (6)
\nHere \\(\\frac{s}{\\Delta t} \\) gives the speed of the cross wire, let it be v.
\nElectric power
\nP= \\(\\frac{W}{\\Delta t}=\\mathrm{Fv} \\) = BI\/v ……………………. (7)
\nPower is also given as force times velocity. From (5) and (7), \u03b5I = BI\/v, \u03b5 = B\/v<\/p>\n
\nDraw a neat diagram of electric motor. Name the parts.
\nAnswer:
\n<\/p>\n
\nAnswer the following questions by observing diagram.
\n(i) Which device function of working does the figure gives?
\nAnswer:
\nElectro motor
\n(ii) What is the angle made by AB and CD with magnetic field?
\nAnswer:
\nAB and CD are perpendicular to the magnetic field. (90 with the magnetic field)
\n
\n(iii) What are the directions of magnetic forces on sids AB and CD?
\nAnswer:<\/p>\n\n
\nAnswer:
\nThe net force is Zero.<\/p>\n
\nA charged particle \u2018q\u2019 is moving with a speed \u2018y\u2019 perpendicular to the magnetic field of Induction B. Find the radius of the path and the time period of the particle.
\nSolution:
\nLet us assume that the field is directed into the page as shown in figure. Then the force experienced by the particle is F = qvB, We know that this force is always directed perpendicular to velocity. Hence the particle moves along a circular path and the magnetic force on a charged particle acts like a centripetal force.
\n
\nLets r be the radius of the circular path
\nWe know that centripetal force = mv2<\/sup>\/r
\nqvB =mv2<\/sup>\/r
\nSolving this equation, we get; r = mv \/ Bq
\nTime period of the particle; T = 2\u03c0r\/v
\nSubstituting in above equation, we get T = 2\u03c0m\/Bq<\/p>\n
\nThe magnetic flux inside a coil of 400 turns changes for each single turn with time as shown in figure. Determine the maximum induced emf generated In the coil. Is there any change in induced EMF from t = 0.1 second to 0.3 second?
\nSolution:
\nFrom the given graph, the increase in magnetic flux through one turn of coil \u00a1n 0.1 second is 0.00 1 Wb. According to Faraday\u2019s law, the maximum induced emf generated in the coil is given by.
\n\u03b5 = N\u0394\u03a6\/\u0394t
\nSubstituting the values, we get 400 (0.001\/0.1) = 4V
\nFrom graph, there \u00efs no change In magnetic flux through coil from t = 0.1 s to 0.3s.
\nHence no emf is generated.
\n<\/p>\n
\nFind the length of the conductor which is moving with a speed of 10 m\/s in the direction perpendicular to the direction of magnetic field of induction 0.8 T, if it induces an emf of 8V between the ends of the conductor.
\nSolution:
\nGiven that B = 0.8T V = 10 m\/s and \u03b5 = 8V
\nUsing \u03b5= BIv
\n8 = 0.8 (l) (10)
\nl (length of the conductor) = \\(\\frac{8}{0.8 \\times 10}=\\frac{8}{8} \\) = 1 m<\/p>\n
\nA circular coil of radius 10 cm, 500 turns, and resistance 2W is placed with its plane perpendicular to the horizontal component of the earth\u2018s magnetic field. It is rotated about its vertical diameter through 180\u00b0 in 0.25 sec. Estimate the magnitudes of the EMF and current induced In the coil. (Horizontal component of the earth\u2018s magnetic field at the place
\nis 3.0 x 10-5<\/sup> T)
\nSolution:
\nEarth\u2019s magnetic field \u2018B\u2019 = 3.0 x 10-5<\/sup> T
\nArea of the coil = \u03c0r\u00b2= \u03c0 x 10-2<\/sup>m2<\/sup> (radius = 1o cm = 10-1<\/sup> m \u2192 r2<\/sup> = 10-2<\/sup>m2<\/sup>)
\nInitial flux through the coil
\nQ(initial)<\/sub> = BA cos \u03b8 = (3.0 x 10-5<\/sup>) x (\u03c0 x 10-2<\/sup>) x cos 180\u00b0 = 3\u03c0 x 10-7<\/sup>wb
\n(since the plane of coil is perpendicular to the magnetic field, the angle is zero)
\nFinal flux after rotation
\nQ(fial)<\/sub> = BA cos \u03b8 = 3.0 x 10-5<\/sup> x \u03c0 x 10-5<\/sup> x cos 180\u00b0 = – 3\u03c0 x 10-7<\/sup>wb
\nTotal flux = (3\u03c0 x 10-7<\/sup>) – (3\u03c0 x 10-7<\/sup>) = 6\u03c0 x 10-7<\/sup> wb
\nThe value of estimated emf is
\n\u03b5 = N . \\(\\frac{\\Delta \\Phi}{\\Delta \\mathrm{t}}=500 \\times \\frac{6 \\pi \\times 10^{-7}}{0.25} \\) = 3.8 \u00d7 10-3<\/sup> V
\nThe value of estimated current is
\nI = \\(\\frac{\\varepsilon}{\\mathrm{R}}=\\frac{3.8 \\times 10^{-3}}{2 \\Omega} \\)
\n= 1.9 \u00d7 10-3<\/sup> V<\/p>\n
\nCalculate the flux passing through an area of 50 cm2<\/sup> when it is placed in a magnetic field of induction 1.5 T such that normal to the plane of the area makes an angle 60\u00b0 with magnetic field.
\nSolution:
\n\u03a6 = BA Cos
\n\u03a6 = 1.5 x 50 x 10-4<\/sup> x cos 60\u00b0
\n\u03a6 = 75 x 10-4<\/sup> x \\(\\frac{\\sqrt{3}}{2}\\)
\n\u03a6 = 37.5 x 1.732 x 10-4<\/sup>
\n\u03a6 = 64.95 x 10-4<\/sup> wb<\/p>\n
\nA proton is sent into a transverse magnetic field of Induction 2T with a speed of 3.6 x 106<\/sup> m\/s. What is the force experienced by it?
\nSolution:
\nMagnetic field induction B = 2T
\nSpeed of proton y = 3.6 x 106<\/sup> m\/s
\nCharge on proton q = 1.6 x 10-19<\/sup> c
\nForce experienced by proton: F = qvB
\n= 1.6 x 10-19<\/sup> x 3.6x 106<\/sup> x 2
\n\u2234 F = 115.2 x 10-13<\/sup>
\nF = 1.152 x 10-11<\/sup> N.<\/p>\n
\nA magnetic field Is changing at a rate of 3.5 T\/s. If the coil’s loo turns has calculate the emf induced in the coil. (Area of cross-section of the coil is 150cm2<\/sup>)
\nSolution:
\nArea of the coil : A = 150 cm2<\/sup> = 150 x 10-4<\/sup>m2<\/sup>
\nRate of change of magnetic field = \\(\\frac{\\Delta \\mathrm{B}}{\\Delta \\mathrm{t}} \\) = 3.5 T\/s
\nNo. of turns in the coil : N = 100
\nInduced emf: \u03b5 =N \\(\\frac{\\Delta \\phi}{\\Delta \\mathrm{t}}\\) =N\\( \\frac{\\Delta(\\mathrm{BA})}{\\Delta \\mathrm{t}}\\) = NA \\(\\frac{\\Delta \\mathrm{B}}{\\Delta \\mathrm{t}} \\)
\n\u03b5 = 100 x 150 x 10-4<\/sup> x3.5
\n\u03b5 = 1.5 x 3.5 = 5.25
\nE = 5.25 V<\/p>\n
\nA charged particle is moving at a speed of 3 x 104<\/sup> m\/s along a magnetic field of induction 3 x 10-6<\/sup>T. Calculate the force on the particle If Its charge is 3 mc.
\nSolution:
\nSpeed of the particle : y = 3 x 104<\/sup> m\/s
\nMagnetic field induction : B = 3 x 10-6<\/sup> T
\nCharge on the partIcle : q = 3 x 10-3<\/sup> C
\nForte on the particle: F = qvB sin \u03b8 = 3 x 10-3<\/sup> x 3 x 104<\/sup> x 3 x 10-6<\/sup> x sin \u03b8 (\u03b8 = O)
\nF= 0 newtons.<\/p>\n
\nHe Is one of the leading Scientists of 19th Century, played a crucial role in understanding electromagnetism. He gave lectures which were quite popular among the public and also learnt a lot during the tours. During one such lecture In April 1820, Oersted carried out an experiment that was never performed before. He placed a compass needle underneath a wire and then turned on electric current. The needle of the compass showed deflection.<\/p>\n
\nMichael Faraday was born on 22nd September 1791 in a very poor family in London. He worked as a news paper boy at the age of 13 years. In 1821, he published his work on electromagnetic induction. Encouraged and helped by Sir Humphry Davy, Faraday began his own experiments. He was famous for inventing Dynamo to generate electricity. He introduced new scientific technology like anode, cathode, anion, cation, electrode etc.<\/p>\n
\nGeorge Simon Ohm \u00a1s a German Physicist and a Professor at Munich. Ohm was led to his law by an analogy between the conduction of heat and the electric current. The electric field is analogous to the temperature gradient, and the electric current is analogous to the heat flow.<\/p>\n