NCERT Class 10 Science Chapter 13 Magnetic Effects of Electric Current Extra Questions and Answers
Class 10 Science Chapter 13 Extra Inside Questions and Answers – Magnetic Effects of Electric Current. Here in this Page Class X Students can Learn Extra Questions & Answer 13th Chapter Science fully Inside.
We Provided Here Magnetic Effects of Electric Current Science Chapter 13 Long Answer Type Question, Multiple Choice Questions & Answer, Short Answer Type Questions (2 or 3 marks), and Very Short answer Type Question (1 marks) Solution.
Class 10 Science Chapter 13 Extra Question with Answer – Magnetic Effects of Electric Current
Science Chapter 13 Magnetic Effects of Electric Current Class 10 Inside 5 Marks, 3 marks, 2 Marks & And 1 Marks Important Questions and Answers.
1.) Multiple Choice questions:
1.) Who gave the relationship between electricity and magnetism?
a) Fleming
b) Maxwell
c) Oersted
d) Joule
Ans: c) Oersted
2.) Inside the magnet, the direction of magnetic field lines is from
a) north to south
b) east to west
c) west to east
d) south to north
Ans: d) south to north
3.) According to right hand thumb rule if the thumb of right hand is stretched out in such way that curled finger gives the direction of magnetic field then thumb gives direction of
a) magnetic force
b) magnetic field
c) current
d) b and c
Ans: c) current
4.) What is the nature of magnetic field inside the solenoid?
a) different at different points
b) non uniform
c) uniform
d) continuously changing
Ans: c) uniform
5.) Fleming’sleft hand rule is used to find the direction of
a) magnetic field
b) current
c) motion or magnetic force
d) a and c
Ans: c) motion or magnetic force
6.) Electric motor converts
a) electrical energy to mechanical
b) mechanical to electrical
c) thermal to electrical
d) electrical to thermal
Ans: a) electrical energy to mechanical energy
7.) Fleming’sright hand rule is used to find the direction of
a) magnetic field
b) magnetic force
c) induced current
d) motion
Ans: c) induced current
8.) Electric generator based on the principle of
a) Fleming’sleft-hand rule
b) Fleming’sright-hand rule
c) Right hand thumb rule
d) electromagnetic induction
Ans: d) electromagnetic induction
9.) Electric generator converts
a) electrical energy to mechanical
b) chemical to electrical
c) electrical to chemical
d) mechanical energy to electrical
Ans: d) mechanical energy to electrical
10.) The direct current ___
a) flows in different directions
b) continuously changes its direction
c) always flows in one direction
d) none
Ans: c) always flows in one direction
2.) Fill in the blanks:
1.) The alternating current reverses it’s direction ______.
Ans:
The alternating current reverses it’s direction periodically.
2.) In India the frequency of an AC is ____.
Ans:
In India the frequency of an AC is 50Hz.
3.) The wire with____ colour insulation is the live wire or positive.
Ans:
The wire with red colour insulation is the live wire or positive.
4.) The wire with _____ colour insulation is the neutral wire or negative.
Ans:
The wire with black colour insulation is the neutral wire or negative.
5.) In domestic electric circuit, the earth wire has _____ colour insulation.
Ans:
In domestic electric circuit, the earth wire has green colour insulation.
6.) In our country, in case of domestic electric circuit the potential difference between live wire and neutral wire is ______.
Ans:
In our country, in case of domestic electric circuit the potential difference between live wire and neutral wire is 220 V.
3.) Very short answer questions:
1.) What is the frequency of an AC in India?
Ans:
The frequency of an AC in India is 50Hz.
2.) What is the bar magnet?
Ans:
Bar magnet is the rectangular piece of iron, steel or any other ferromagnetic substance which has permanent magnetic properties and also the bar magnet has south and north pole at its end points.
3.) What is mean by magnetic field?
Ans:
The region surrounding to the magnet in which force of the magnet can be detected is called as magnetic field.
4.) Why two magnetic field lines never cross each other?
Ans:
If the two magnetic field lines are crossing each other means the magnetic field at that point is directed in two directions which is not possible. Hence no two magnetic field lines cross each other.
5.) State right hand thumb rule?
Ans:
According to right hand thumb rule, if we stretched right hand such that thumb is out stretched and fingers are curled around it. If the curled finger gives the direction of magnetic field then thumb gives the direction of current.
6.) Magnetic field produced by current carrying conductor depends on which factor?
Ans:
The magnetic field produced by a current carrying conductor at a given point depends directly on the current passing through it.
7.) For what Fleming’s left-hand rule, us used?
Ans:
To determine the direction of motion or force acting on the conductor Fleming’sleft hand rule is used.
4.) Short answer questions:
1.) Draw a diagram showing magnetic field lines produced by the magnetic field around the current carrying solenoid.
Ans:
Following figure shows the magnetic field lines produced by the magnetic field around the current carrying solenoid.
Fig. magnetic field lines produced in a solenoid
2.) Draw a neat labelled diagram of electric motor and write its principle.
Ans:
Principle:
- The principle of electric motor is based on the magnetic effect of electric current. According to which when a current carrying coil is placed in magnetic field then there will be force acting on the coil which rotates it. This is the principle of electric motor.
- Electric motor is a rotating device which converts electrical energy into mechanical energy. The figure shows the labelled diagram of simple electric motor.
Fig. electric motor
3.) Draw a neat labelled diagram of electric generator and write it’s principle.
Ans:
Principle:
- The electric generator works on the principle of electromagnetic induction. When a straight conductor is continuously moved in a string magnetic field then current is induced in the conductor.
- By using this phenomenon in electric generator, mechanical energy is used to rotate the conductor in a magnetic field to produce electricity.
Fig. electric generator
In case you are missed :- NCERT Extra Questions for Electricity
4.) What is electromagnetic induction? Name the devices working on this principle.
Ans:
- Electromagnetic induction is the phenomenon of producing electromotive force by changing the magnetic field around the electric conductor and vice versa.
- In current lamps, electric generators, induction cooking, induction motors, induction sealing the phenomenon of electromagnetic induction is used.
5.) Draw a neat labelled diagram of one of the common domestic circuits.
Ans:
The following diagram shows the common domestic circuit.
Fig. Common Domestic Circuit
6.) Explain the need of earthing?
Ans:
- In our house we receive 220V of an AC electric power whose frequency is 50Hz. In domestic electric circuit, the wire with red insulation is the live wire and the wire with black insulation is the neutral wire. The potential difference between the live wire and neutral wire is 220V.
- And the wire with green insulation is the earth wire which is directly connected to the metal which deep inside the earth.
- When there is large current or leakage of current then it will go directly through earth wire and to the ground where metal is deeped. So, earthing protects us from severe electric shocks. Because of this in domestic electric circuit earthing is necessary.
7.) What is AC?
Ans:
- In AC currents, charge flows in both direction that is AC current changes its direction periodically and hence it is also called as bidirectional current.
- In India frequency of AC is 50 Hz.
- The magnitude of AC current is varying with time.
- AC circuit possesses registers, capacitors and inductors also.
- The power factor for AC circuit is lies between 0 and 1.
- There are low energy losses for AC circuits.
Fig. AC current
- AC circuits are used for long distance transmission because of low energy losses.
- In India the frequency of AC current is 50 Hz, and it changes its direction 2 times in one cycle.
2 * 50 =100 times in 1 second.
Thus, AC used in India changes its direction 100 times in 1 second.
8.) What is DC?
Ans:
- In DC current charge flows only in one direction and hence it is also called as uni-directional current.
- Frequency of DC current is zero. The magnitude of DC current is fixed or constant. DC circuit possesses mostly register only.
- The power factor for DC circuits is always 1.
- In DC circuits there is a high energy loss.
- DC circuits are not used for long distance transmission because of high energy losses.
Fig. DC current
5.) Long answer questions:
1.) What is electromagnetic induction and how it is applicable in electric generator? Explain.
Ans:
Electromagnetic induction is the phenomenon of producing induced current in a coil by changing the magnetic field around the coil and vice versa.
Principle:
- The electric generator works on the principle of electromagnetic induction. When a straight conductor is continuously moved in a string magnetic field then current is induced in the conductor.
- By using this phenomenon in electric generator, mechanical energy is used to rotate the conductor in a magnetic field to produce electricity.
Explanation:
- An AC generator is an electronic device which is used to convert mechanical energy into electrical energy. The labelled circuit diagram of electric generator is as shown in figure.
- It consists of a rotator coil PQRS which has been placed in between two poles of magnet the end points of coil are connected to two rings R1 and R2. B1 and B2 are the brushes and axel are attached internally to this ring. The outer ends of brushes are directly connected to the galvanometer for measuring current.
- When the coil PQRS is rotating in clockwise direction then according to Fleming’s right-hand rule, the current is induced in side PQ and RS. The current to the coil depends on number of turns. If number of turns increased current get added up and galvanometer shows large deflection. After half rotation, the direction of current induced changes. Hence the direction of current changes after every half rotation which is called as an AC current and this device is called AC generator.
- To produce a unidirectional DC current, we have to use a split ring type of commutator, due to which each brush will be in contact with only one arm and hence unidirectional current flows called as DC current like in an electric motor.
2.) How we can use the current carrying solenoid to produce the permanent electromagnet?
Ans:
- Solenoid is a cylindrical shaped closely wrapped coil by the wire of many numbers of circular turns of insulated copper wire. When the current is passed through the solenoid, the magnetic field is generated around it which has similar nature like the magnetic field around the bar magnet.
- In fact, the magnetic field generated around the solenoid creates magnetic poles due to which one pole of solenoid act as North Pole and other as a South Pole. Inside the solenoid the magnetic field lines are straight and parallel to each other, which indicates that at all points inside a solenoid magnetic field is constant forming the uniform magnetic field inside the solenoid.
- When the ferromagnetic materials are placed inside the solenoid then the metal produces strong magnetic field around solenoid and hence it gets permanently magnetized and act as a permanent electromagnet.
- Ferromagnetic materials are the materials having permanent magnetism and magnetic susceptibility is high, due to which even after removal of magnetic field they don’t loses their magnetization and hence get permanently magnetized. Because of this reason they are used for producing permanent electromagnet.
Fig. production of permanent electromagnet
The above figure shows the current carrying solenoid coil is used to produce permanent electromagnets.
3.) Explain what is the nature of magnetic field lines produced by current carrying circular loop in detail?
Ans:
- When a current is passed through a circular loop of wire, the magnetic lines of forces are produced in the form of concentric circles with the centre is the point at which the wire passes through the board.
- The magnetic field concentration or strength is more at the centre of the concentric circles formed. The magnetic field lines representing circular concentric loops looks like a straight line near the centre of the concentric circles.
- And these concentric circles become larger and larger as we move away from their centres.
- Because the magnetic field strength decreases as we go away from the current carrying conductor and hence if distance is increased strength of the magnetic field decreases.
- Thus, if we are moving away from the centre of the circular loop that is distance from the current carrying conductor is increased due to which magnetic field strength is decreased and because of this the lines keep on diverging.
Fig. magnetic field produced by current carrying circular loop
4.) Why we use fuse of proper rating in domestic electric circuit? Explain.
Ans:
- Fuse wire is a safety device connected in series in electrical circuits to protect the circuit from the extra current flow. The rating of the fuse wires is fixed.
- When the extra current greater than the rating flows through the circuit, due to which fuse get heated and meals to break the circuit and protect the electrical appliances from damaging.
- The fuse wire is having specific melting point, if temperature is increased than melting point of fuses then they get melts thereby protecting the circuits. The fuses are connected in series to the main source and they are having fixed rating.
- We have to connect the fuse of required rating in a circuit according to the current required. The fuse of 10 A rating shall pass 10 A current only and if current exceeds, it gets heated and melts thereby protecting the electrical appliances.
- If we used the fuses of rating greater than required rating then it allows the extra current which will damage the electrical appliances. Because of this reason, the fuse with defined rating should not be replaced by one with the larger rating.
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