Magnetic Field Due to a Current Carrying Conductor The magnetic field around a straight conductor carrying current is in the form of closed circular loops, in a plane perpendicular to the conductor. What will happen if a bar magnet is t pushed into the coil ii withdrawn from inside the coil iii held stationary inside the coil? Solution: i Right-hand thumb rule Imagine that we are holding a current carrying straight conductor in the right hand such that the thumb points towards the direction of current. This indicates that the magnetic field is the same at all points inside the solenoid. This experiment can also be done with the south pole of magnet, we will observe the deflection in galvanometer, but it would be in opposite direction to the previous case. For a rare-earth neo super magnet, you'd only need less than 100 turns of wire.
Why is it necessary to earth metallic appliances? Filament of bulb is made of strong metal with high melting point suchas tungsten. This touching of the live wire and neutral wire directly is known as short-circuiting. If the supply voltage is 220V, what result do you expect? On its cross sectional area A 3. The magnetic field inside a long straight solenoid-carrying current i is zero ii decreases as we move towards its end iii increases as we move towards its end iv is the same at all points Answer: iv Is the same at all points. Because of their inefficiency and the difficulty of machines that produced very high voltages, electrostatic generators had low power ratings, and were never used for generation of commercially significant quantities of electric power. Resistivity : The resistance offered by a wire of unit length and unit cross-sectional area is called resistivity.
The earth wire provides a low resistance conducting path for electric current. Construction: It consists of the following main parts: 1. Question 27 State whether the following statements are true or false. Now the coil is rotated clockwise. Typically operated by means of pedal power, a converted bicycle trainer, or a foot pump, such generators can be practically used to charge batteries, and in some cases are designed with an integral inverter. The two ends of this coil are connected to the two rings R1 and R2.
This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. It convert mechanical energy into electrical energy. The direction of the induced current changes once in each a two revolutions b one revolution c half revolution d one-fourth revolution Q16: From which of the following case, the current in the loop will not be induced? This creates a magnetic field as shown above. Experimenters found that using multiple turns of wire in a coil could produce higher, more useful voltages. The answer for the above question is also similar. Electron will come in motion to flow current through resistor 3. Question 11 Draw a labelled diagram of an electric motor.
You may want to wind a string around the end of the shaft, then pull it sharply to turn the magnets. Question 22 Which of the following correctly describes the magnetic field near a long straight wire? She has started this educational website with the mindset of spreading Free Education to everyone. Allow the glue to dry for several minutes the instructions on the container can tell you exact drying times for your type of glue. Y is the closest followed by X than Z. This type of generator is used in the. The split ring helps in changing the direction of the current.
For example, the uniform magnetic field which exists inside a current-carrying solenoid can be represented by parallel straight lines pointing from its S-pole to N-pole as shown in figure. Explain its principle and working. The horseshoe-shaped magnet A created a magnetic field through the disk D. The current passing through the circuit formed by these wires is very large and consequently a high heating effect is created which may lead to fire. Top one will be South Pole and bottom face will be the North Pole. Can you determine the north and south poles of a current-carrying solenoid with the help of a bar magnet? When this conductor is placed in a magnetic field, it experiences a force due to mutual interaction of these two magnetic fields. Dynamos are no longer used due to the size and complexity of the needed for high power applications.
Now, Total current substitute the value of Thus, we conclude that the reciprocal of total effective resistance of theseveral resistors connected in parallel is equal to the sum of the reciprocals of the individual resistances. The resistance of the circuit becomes zero and excessive current starts to flow through it. A small , or is connected to a low-power generator to supply currents at typical wind or cruising speeds. Permanent magnets can be made using hard magnetic materials. Commutators reverses the direction of current in armature coil.
Induction generators are useful in applications such as minihydro power plants, wind turbines, or in reducing high-pressure gas streams to lower pressure, because they can recover energy with relatively simple controls. Electric potential Difference : It is defined as the work done in carrying a unit charge from one point to another in an electric circuit. Thus the direction of current in the external circuit changes after every half rotation. . In an electric circuit the electric current flow in an opposite direction to the flow of electron —ve charge. 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? It was also the discovery of the principle of dynamo , which replaced permanent magnet designs.