Magnetic Effects of Electric Current Class 10 Free Study Material PDF
0 likes•1,761 views
The document covers the magnetic effect of current, detailing concepts such as Oersted's experiment, Ampere's swimming rule, and various laws like Fleming's left and right hand rules. It explains how electric motors and generators convert energy, the properties of magnetic fields and field lines, and the importance of safety in domestic electric circuits. Additionally, it discusses the characteristics and applications of alternating current (AC) and direct current (DC).
Magnetic Effects of Electric Current Class 10 Free Study Material PDF
- 1. MAGNETIC EFFECT OF CURRENT 1. Introduction: Magnetic properties 2. Magnetic Effect of Current – Oersted’s Experiment 3. Ampere’s Swimming Rule 4. Maxwell’s Cork Screw Rule 5. Right Hand Thumb Rule 6. Magnetic Field due to Infinitely Long Straight Current – carrying Conductor 7. Magnetic Field due to a Circular Loop carrying current 8. Magnetic Field due to a Solenoid 9. Fleming’s left hand rule 10.Electric motor(AC/DC) 11.Electromagnetic Induction and Fleming’s right hand rule 12.Electric generator (AC/ DC): Dynamo 13. Domestic electric circuit Topics covered All right copy reserved. No part of the material can be produced without prior permission
- 2. MAGNETIC FIELD AND FIELD LINES Properties of Magnets: 1. They have two permanent poles namely, North and South and poles cannot be isolated. 2. Like poles repel each other and unlike poles attract each other. 3. When magnet is cut into pieces they will behave like separate magnets with same property but lesser magnetic strength compared to whole magnet. 4. The freely suspended bar magnet will align in geographic N – S direction. 5. When magnet is subjected to mechanical damages (falling on a hard surface, heating, piling, hammering etc.) they lose their magnetic properties 6. Depending on application we have, i) dumbbell magnet, ii) ring magnet, iii) bar magnet, iv) horse shoe magnet, v) compass needle etc. 7. Note: There is a magnet without poles is called toroid, whose north and south poles are joined. 8. Magnets are naturally available (Earth) and can be prepared artificially for use. Introduction: All right copy reserved. No part of the material can be produced without prior permission
- 3. MAGNETIC FIELD AND FIELD LINES Definition: Magnetic field is space or region surrounding the magnet (or current carrying conductor) in which another magnet will experience the force of magnetostatics. It is denoted by B SI unit T (tesla) and a vector. Definition: Magnetic field lines are the imaginary path in which an isolated north pole can travel from one pole to another in space. Properties: 1. Magnetic field lines or Magnetic lines of force, travel from north pole and reach south pole in its vicinity or travel up to infinity. 2. M.F.L. are continuous closed curves and can pass through conductors 3. Note: Superconductors does not allow MFL to enter inside hence B = 0 (inside). 4. The tangent drawn at any point on the MFL gives direction of MF at that point. 5. No two MFL can intersect each other since two value of MF doesn’t exist at a point. 6. MFL are crowded at strong MF (poles) but diverged at weak MF region. Introduction: All right copy reserved. No part of the material can be produced without prior permission
- 4. MAGNETIC FIELD AND FIELD LINES OF A BAR MAGNET Experimental image Illustrative diagram All right copy reserved. No part of the material can be produced without prior permission
- 5. N Magnetic Effect of electric Current: An electric current (i.e. flow of electric charge) produces magnetic effect in the space around the conductor called strength of Magnetic field or simply Magnetic field. Hans Christian Oersted’s Experiment: When current is passing through the wire over the compass needle in anti-clockwise direction, the needle was found to deflect towards West direction from its normal position. E K I N E K I When current direction is reversed through the wire over the compass needle, the needle was found to deflect towards East direction from its normal direction. All right copy reserved. No part of the material can be produced without prior permission
- 6. B B Rules to determine the direction of magnetic field: Ampere’s Swimming Rule or SNOW Rule: Imagining a man who swims in the direction of current from south to north facing a magnetic needle kept under him such that current enters his feet then the North pole of the needle will deflect towards his left hand, i.e. towards West. Maxwell’s Cork Screw Rule or Right Hand Screw Rule: If the forward motion of an imaginary right handed screw is in the direction of the current through a linear conductor, then the direction of rotation of the screw gives the direction of the magnetic lines of force around the conductor. S I I I All right copy reserved. No part of the material can be produced without prior permission
- 7. Right Hand Thumb Rule or Curl Rule: If a current carrying conductor is imagined to be held in the right hand such that the thumb points in the direction of the current, then the tips of the fingers encircling the conductor will give the direction of the magnetic lines of force. Magnetic Field Lines due to current carrying conductor: Direction of B is determined by Right Hand Screw Rule. It is perpendicular to the plane of the diagram and entering into the plane at as shown in diagram. I B B I I B All right copy reserved. No part of the material can be produced without prior permission
- 8. I I Different views of direction of current and magnetic field due to circular loop of a current carrying coil: B I I B B Current moving in clock wise direction representing the face towards us (Inwards) as South pole of bar magnet Current moving in anti-clock wise direction representing the face towards right (outwards) as North pole of bar magnet All right copy reserved. No part of the material can be produced without prior permission
- 9. Magnetic Field due to a current carrying Solenoid: I I x x x x x x x TIP: When we look at any end of the coil carrying current, if the current is in anti-clockwise direction then that end of coil behaves like North Pole and if the current is in clockwise direction then that end of the coil behaves like South Pole. Hence it behave like bar magnet. B All right copy reserved. No part of the material can be produced without prior permission
- 10. Force acting on a current carrying conductor: 1. A current carrying conductor is freely suspended from a stand with the help of thread and connecting wires as shown in fig. 2. A horse shoe magnet is placed over the conductor at centre such that, north pole on top and south pole at bottom and direction of motion of conductor is noted. 3. The direction of poles are now reversed and the direction of motion of conductor is noted. 4. The polarity of cell is reversed and above steps is repeated and the direction of motion of conductor is noted in each case. 5. The conclusion is drawn from the observations. Conclusion: i) The direction of motion of conductor is towards east, when the current is outward plane perpendicular with direction of magnetic field from N – S and current moving into the plane and direction of magnetic field is S – N. ii) The direction of motion of conductor is towards west for other two directions of current and MF. ACTIVITY: 3 D view: https://youtu.be/rtjGH0B-vVA All right copy reserved. No part of the material can be produced without prior permission
- 11. FLEMING’S LEFT HAND RULE: I Stretch first three fingers of your left hand mutually perpendicular to each other such that, fore (Index) finger represents direction of magnetic field, middle finger represent direction of current, then thumb finger show the direction of force (motion) of the conductor. Conclusion: i) The direction of motion of conductor is towards east, when the current is outward plane perpendicular with direction of magnetic field from N – S and current moving into the plane and direction of magnetic field is S – N. ii) The direction of motion of conductor is towards west for other two directions of current and MF. All right copy reserved. No part of the material can be produced without prior permission
- 12. ELECTRIC MOTOR: AC MOTOR: DC MOTOR: All right copy reserved. No part of the material can be produced without prior permission
- 13. It is a device which converts electrical energy (AC/DC current) into mechanical energy. Principle: When a current carrying conductor placed between magnetic field it will undergo rotation based on Fleming’s left hand rule. Construction: As shown in diagram all the components are placed and necessary AC/DC current is given. Working: When current is passed through armature in clock wise direction, according to Fleming’s left hand rule, left part (towards North) of armature will experience upward motion and right part will experience downward motion and it starts rotating, due to commutators the direction of rotation is such that it will be according AC/DC cycle which are in contact with metallic (carbon) brush and hence to the source. Conclusion: Electrical energy is converted into mechanical energy. Application: Fan, mixer, blender, washing machine etc. AC/DC MOTOR: All right copy reserved. No part of the material can be produced without prior permission
- 14. The relative motion between closed conducting wire and magnet will induce electric current in the coil without any electrochemical reaction. Faraday’s Experiments: Fig. having solenoid and magnet produce current whenever there is relative motion between coil and magnet which is noticed in deflection of galvanometer needle. Also notice that the direction of current is reversed when there is change in the pole of the bar magnet and its relative motion with coil as we notice that, current moving in anticlockwise represents North pole of magnet and in clockwise it will behave as South pole of the magnet. Faraday’s Electromagnetic Induction: Current direction All right copy reserved. No part of the material can be produced without prior permission
- 15. Stretch first three fingers of your right hand mutually perpendicular to each other such that, fore (Index) finger represents direction of magnetic field, middle finger represent direction of current induced, then thumb finger show the direction of force (motion) of the conductor. Fleming’s right hand rule: Alternating current (AC) is time varying current which varies sinusoidal or cosinusoidal with time. Direct Current (DC) is having fixed magnitude and won’t change with time. AC and DC current: All right copy reserved. No part of the material can be produced without prior permission
- 16. ELECTRIC GENERATOR: It is a device which converts mechanical energy into electrical energy (AC/DC current). Principle: When a coil is rotated between magnetic field there will be induced current/emf based on Electromagnetic Induction. Construction: As shown in diagram all the components are placed and necessary AC/DC current is drawn across load resistor. Working: When armature is rotated between strong magnetic field according to Electromagnetic Induction and Fleming’s right hand rule there will be induced current/emf in the coil and it is drawn across resistor, which are in contact with metallic (carbon) brush and hence to the battery. Conclusion: Hence the mechanical energy is converted into electrical energy. Load Resistor All right copy reserved. No part of the material can be produced without prior permission
- 17. ADVANTAGES OF AC OVER DC 1. The cost of producing AC much lesser than that of DC. 2. AC can be easily converted into DC using rectifier. 3. AC can be easily transmitted for long distances compared to DC. 4. AC can be controlled much easily compared to DC without much loss of energy. DISADVANTAGES OF AC OVER DC 1. AC cannot be used in electrolysis as that of DC. 2. AC is more dangerous than DC. 3. AC will have more magnitude (Positive value) compared to DC magnitude. All right copy reserved. No part of the material can be produced without prior permission
- 18. The electric circuit designed for the purpose of domestic use (house, factory, SSI etc) is called domestic electric circuit. DOMESTIC ELECTRIC CIRCUIT: The electric circuit is having Live wire ( +ve): Neutral wire(- ve): Earth wire (0 V): Insulated colour wires, Two circuits one of 15 A rating fuse for Heavy appliances such as Heater, oven etc. and 5 A fuse for bulb, fan etc. The applied voltage across mains is, 220 – 240 V in India with 50 Hz frequency. S1 S2 S3 All right copy reserved. No part of the material can be produced without prior permission
- 19. 1. Live wire: It is kept as positive with 220 V supply from mains. 2. Neutral wire: It is kept at 0 V w.r.t. live wire for completing the circuit connection. 3. Earth wire: It is connected to earth through metallic wire which is at 0 V and can allow the excess charges produced easily whenever electrical hazard takes place. 4. Switch( S1, S2 …) : It is controlling component which is connected in series with live wire to operate appliances whenever needed. 5. Fuse: It is safety device which is connected in series with appliances with suitable rating for easy melting and disconnection whenever there is short circuit or overloading in circuit. It is made up of alloys of Al, Fe, Cu, Sn, Pb etc. 6. MCB (Miniature Circuit Breaker): Designed to break circuit during electrical hazards based on electromagnetic induction or eddy current production. All right copy reserved. No part of the material can be produced without prior permission
- 20. 7. Short Circuit: When live wire coincide with neutral wire directly (accidentally) there will be sudden flow of charges from high potential to low potential causing enormous heat according to Joule’s heating effect in the circuit . 8. Over loading: When there are more number of appliances are connected in parallel at a time the effective resistance will reduce too small giving the condition of short circuiting called as overloading. 9. Electrical Hazard: It is electric shock which produce enormous heat which is capable of burning whole domestic electric circuit due to short circuit or overloading or failure in the earthing of appliances. All right copy reserved. No part of the material can be produced without prior permission
- 21. SUMMARY: 1. Magnetic field and magnetic field line properties 2. Current carrying conductor and coil possess magnetic properties 3. Various laws and rules explaining the direction of magnetic field produced due to current carrying conductor, such as right hand thumb rule. 4. When current appear to travel in anti clockwise direction in a closed coil it behave like North pole, if it is clockwise it resembles South pole of a magnet 5. The combination of such closed loops form solenoid and when current is passed through it behaves like bar magnet. 6. The direction of force experienced by current carrying conductor in uniform magnetic field – Fleming’s left hand rule, its application in electric motors such as grinder, fan, washing machine etc. 7. Production of induced current/ emf due to relative motion between coil and magnet – Electromagnetic induction. All right copy reserved. No part of the material can be produced without prior permission
- 22. 8. Current is induced in a coil when subjected rotation in a uniform magnetic field – Fleming’s right rule 9. Application of EMI in producing current due to various sources – AC generation in Hydroelectric power plants, wind mill etc. 10. Purposeful use of electricity using domestic electric circuit with proper safety devices and precautions All right copy reserved. No part of the material can be produced without prior permission