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What Device Reverses the Current? - Science

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प्रश्न

 What device reverses the current?

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उत्तर

 A commutator (split rings) reverses the current.

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  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 2: Magnetic Effects of Electric Current - Exercise 3 [पृष्ठ ९२]

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लखमीर सिंग Physics (Science) [English] Class 10
अध्याय 2 Magnetic Effects of Electric Current
Exercise 3 | Q 20.2 | पृष्ठ ९२

वीडियो ट्यूटोरियलVIEW ALL [2]

संबंधित प्रश्न

Describe some experiment to show that the magnetic field is associated with an electric current. 


What is Maxwell's corkscrew rule? For what purpose is if used?


When the switch S is closed in the figure given below, the pointer of the galvanometer moves to the right.  

 

If S is kept closed, will the pointer:

(a) return to zero?
(b) stay over on the right?
(c) move to the left and stay there
(d) move to and fro until S is opened


In the Activity shown below, how do we think the displacement of rod AB will be affected if

  1. current in rod AB is increased
  2. a stronger horse-shoe magnet is used
  3. length of the rod AB is increased?
  • Take a small aluminium rod AB (of about 5 cm). Using two connecting wires suspend it horizontally from a stand, as shown in Fig.
  • Place a strong horse-shoe magnet in such a way that the rod lies between the two poles with the magnetic field directed upwards. For this put the north pole of the magnet vertically below and south pole vertically above the aluminium rod (Fig.).
  • Connect the aluminium rod in series with a battery, a key and a rheostat.
  • Now pass a current through the aluminium rod from end B to end A.
  • What do you observe? It is observed that the rod is displaced towards the left. You will notice that the rod gets displaced.
  • Reverse the direction of current flowing through the rod and observe the direction of its displacement. It is now towards the right.
  • Why does the rod get displaced?


A current-carrying rod, AB, experiences a force perpendicular to its length and the magnetic field. Support for the magnet is not shown here, for simplicity.


What is the function of a split ring in an electric motor?


Observe the following diagram and choose the correct alternative:


When the resistance of a conductor increases, the current ____________ .

(b) State whether the following statements are true or false:

(i) Magnetic poles exist in pairs.

(ii) Global warming is a desirable aspect of the intensified greenhouse effect.


(ii) Global warming is a desirable aspect of the intensified greenhouse effect.


Read the given passage and answer the following questions:

The home electrical connection consists of ‘live’, ‘neutral’ and ‘earth’ wires. The ‘live’ and the ‘neutral’ wires have potential difference of 220 V. The ‘earth’ is connected to ground. Due to a fault in the equipment or if the plastic coating on the ‘live’ and the ‘neutral’ wires gives a way the two wires come in contact with each other and a large current flows through it producing heat. If any inflammable material (such as wood, cloth, plastic, etc.) exists around that place it can catch fire. Therefore a fuse wire is used as a precautionary measure.

  1. Name the two wires having potential difference of 220 V.
  2. What is a short circuit?
  3. Write the function of a fuse.

If the key in the given arrangement is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane ABCD, the lines are ____________.


A uniform magnetic field exists in the plane of paper pointing from left to right as shown in Figure. In the field an electron and a proton move as shown. The electron and the proton experience


In the arrangement shown in Figure  there are two coils wound on a non-conducting cylindrical rod. Initially the key is not inserted. Then the key is inserted and later removed. Then


Why do we cover plug pin holes which are within the reach of children with cellotape or a plastic cover when not in use?


______ are also used to remove splinters of steel or iron in hospitals dealing with eye injuries.


An electric bell contains an ______, consisting of coils of insulated wire wound around
iron rods.


A wire with green insulation is usually the live wire of an electric supply.


As shown in the diagram an aluminium rod 'AB' is suspended horizontally between the two poles of a strong horse shoe magnet in such a way that the axis of rod is horizontal and the direction of the magnetic field is vertically upward. The rod is connected in series with a battery and a key.

State giving reason:

  1. What is observed when a current is passed through the aluminium rod from end B to end A?
  2. What change is observed in a situation in which the axis of the rod 'AB' is moved and aligned parallel to the magnetic field and current is passed in the rod in the same direction?

A rectangular loop ABCD carrying a current I is situated near a straight conductor XY, such that the conductor is parallel to the side AB of the loop and is in the plane of the loop. If a steady current I is established in the conductor as shown, the conductor XY will ______.


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