PRACTICE PAPER
PHYSICS (2020)
CLASS X MAGNETIC EFFECT OF ELECTRIC CURRENT
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I. Short Answer Type Questions
- State briefly two methods of producing induced current.
- Give S.I unit of the following:
(a) Magnetic field strength (b) Magnetic flux (c) Magnetic intensity. - Repulsion is a sure test of magnetism.' Justify'.
- How will the magnetic field intensity at the center of a circular coil carrying current change, if the current through the coil is doubled and radius is halved?
- State the principle behind the working of a transformer.
- What is the role of the two conducting stationary brushes in a simple electric motor?
- State the effect on the strength of the magnetic field produced at a point near a straight conductor if the electric current flowing through it increases.
- State a difference between the wires used in an element of electric heater and in a fuse.
- State the observation made by Oersted on the basis of his experiment with current-carrying conductors.
- State two properties of magnetic lines of force? List two sources of the magnetic field.
- Why does a compass needle deflect when brought near a bar magnet?
- The magnetic field lines in a given region are uniform. Draw a diagram to represent.
- Define the term induced current. Write two rules which help in determining the direction of induced current.
- What is the function of the earth wire in the domestic electric circuit?
- What is the principle of the electric motor? State the function of
(a) Split ring (b) field magnet used in an electric motor. - What is a solenoid?
- State three-factor on which the magnetic field produced by a current-carrying solenoid depends.
- How many times does AC use in India, change direction in one second? (f=50 cycle/s).
- A current-carrying conductor placed in a magnetic field experiences a force. The displacement of the conductor in a magnetic field can be increased by
(a) Decreasing the magnetic field.
(b) Decreasing the current in the conductor.
(c) Increasing the magnetic field.
(d) None of the above. - A positively charged particle say an alpha particle projected towards the west is deflected toward the north by a magnetic field. The direction of the magnetic field is :
(a) Upward (b) Downward (c) Towards south (d) Towards east. - Which of the following properties of a proton can change when it moves freely in a magnetic field:
(a) Mass (b) Speed (c) Velocity (d) Momentum - Name and state the rule which determines the direction of the magnetic field around a straight current-carrying conductor.
- State the value of the potential difference between the live wire and neutral wire in our country.
- Why do not two magnetic field lines intersect each other?
- What is an electric fuse? Where it is connected in a circuit? Which wire do we connect in a fuse?
- What is meant by a magnetic field? Mention two parameters that are necessary to describe it completely.
- If field lines of a magnetic field are crossed at a point, what does it indicate?
- Name the type of current used in household supply and in a cell.
II. Short Answer Type Questions;
- What does the divergence of magnetic field lines near the ends of a current-carrying straight solenoid indicate?
- For the current-carrying solenoid as shown in fig. draw magnetic field lines and giving reason explain that out of three points A, B, and C at which point the field strength is maximum and at which point is minimum?
- (a) What is short-circuiting? (b) What is overloading? How can you avoid overloading?
- (a) What is the standard color code followed for
(i) live (ii) neutral and (iii) earth wires used in electric circuits?
(b) Which part of an electric appliance is earthed and why? - Mention the angle between a current-carrying conductor and magnetic field for which the force experienced by this current-carrying conductor placed in a magnetic field is largest.
- When a current-carrying conductor is kept in a magnetic field, it experiences a force. List the factors on which direction of this force depends.
- Mention the provision of two different current ratings in our domestic circuits. Explain with reason. the advantage of such a provision.
- The given magnet is divided into three parts A, B and C. Which part of a bar magnet, the strength of the magnetic field is maximum and minimum?
- State the factors on which strength of the magnetic field at a point due to a current-carrying conductor depends?
- The rectangular coil of copper wires is rotated in a magnetic field. The direction of induced current change once in each
(a) One revolution (b) one-fourth revolution
(c) Half revolution (d)two revolutions - What is an electromagnet? Write two uses of an electromagnet?
- State and define S.I unit of the magnetic field? State the effect of the magnetic field on the path of a moving charged particle.
- A current-carrying conductor is placed perpendicular to the uniform magnetic field. What happens to the displacement of the conductor if
(i) Strength of current increases (ii) If horseshoe magnet is replaced by a weak horseshoe magnet. - Define electromagnetic induction? Two circular coils A and B are placed close to each other. If the current in the coil A is changed, will some current be induced in coil B? Explain.
- Why does a current-carrying conductor keep in a magnetic field experience force? What is the direction of force acting on the conductor?
- All the household electric appliances are connected in parallel. List two types of arrangements.
- (a) Define the term current rating of an electric fuse?
(b) Name the material used to make electric fuse?
(c) Name two safety measures commonly used in electric circuits and appliances? - Draw magnetic field lines produced around a current-carrying straight conductor passing through cardboard. How will the strength of the magnetic field change, when the point where the magnetic field is to be determined, is moved away from the straight wire carrying constant current? Justify your answer.
- A current-carrying conductor produces a magnetic field around it. Is there a similar magnetic field produced around a thin beam of moving
(a) Electrons or(b)Neutrons ? - Explain the function of an earth wire. Why is it necessary to earth metallic appliances?
- When a glass rod is rubbed with silk clothes then glass rod loses 10^15 electrons. Find the charges on a glass rod and silk clothes.
III. Long answer type questions:
1. A coil of insulated copper wire is connected to a galvanometer as shown in the fig. State your observations when a bar magnet is:
(a) Pushed into the coil with its North pole entering first.
(a) Pushed into the coil with its North pole entering first.
(b) Held at rest inside the coil.
(c) Name the phenomenon responsible for the above observation.
2. (a) Write the special name given to the coil AB which has many circular turns of insulated copper wire.
(b) List two factors on which the strength of the magnetic field produced by AB depends.
3. (a) Distinguish between A.C and D.C?
(b) Which source produces alternating current?
(c) Mention the advantage of A.C. over D.C for long-distance transmission. (d) List two differences between the electric motor and generator.
4. How the strength of the magnetic field due to current carrying loop be affected:
(a) The radius of the loop is reduced to half its original value?
(b) The strength of current through the loop is doubled?
(c) No.of turns of wire in the coil.
5. Explain the function of fuse in a domestic electric circuit? An electric oven having a power rating 2000 W to 220 V is used in an electric circuit having a fuse of 5 A rating. What is likely to happen when the oven is switched on? Explain.
6. PQ is a current-carrying conductor producing a magnetic field around it. A and B are two points at a distance r1 and r2 from it. If r1> r2, where is the magnetic strength greater and why?
7. Draw a diagram to show the magnetic field lines around a bar magnet. List any two properties of magnetic field lines.
8. Explain the magnetic effects of current with the help of an activity along with the labeled diagram.
9. Explain briefly two different ways to induce a current in a coil. State the rule which determines the direction of induced current.
10. Name two electric appliances of daily use in which electric motor is used. Name and state the principle on which an electric motor works.
11. You are given a strong bar magnet and a magnetic compass needle. Describe an activity by which the magnetic field lines due to the bar magnet can be drawn.
12. A circuit has a fuse of 5 A. Find the maximum number of 100 W, 220 V lamps that can be used in the circuit.
13. What does the magnetic field pattern inside the solenoid indicate? State how this field be utilized to make an electromagnet. List two ways by which the strength of this magnet can be increased.
14. List four important features of domestic electric circuits. Draw a schematic diagram of, domestic circuit showing live, neutral and earth wires.
15. Describe any five safety measures that should be taken while dealing with electric appliances connected in a domestic electric circuit.
16. State Fleming's left-hand rule. A coil of insulated copper wire is connected to a galvanometer. What happens if a bar magnet is
(a) Pushed into the coil?
(b) Withdrawn from inside the coil
(c) Held stationary inside the coil. Give reasons for your observation.
17. What are magnetic field lines? List any two characteristics of field lines. Draw the pattern of magnetic field lines due to the current-carrying conductor loop.
18.(a) Name four appliances in an electric motor that is used as an important component. In what respect it is different from the generator?
(b) Define the terms used in the generator
(i)Armature (ii) slip rings (iii) brushes.
19.In the experiment to show that a current-carrying conductor when placed in the uniform magnetic field experience the force. What happens when you reverse the terminals of the battery the direction of current is perpendicular to the direction of the magnetic field state your observation.
20. A compass needle is placed near a current-carrying wire. State your observation for the following cases and give the reason for the same in each case.
(a) The magnitude of electric current in the wire is increased
(b) The compass needle is displaced away from the wire.
21. The potential difference between a live wire and a neutral wire is
(a) 200 volt (b) 150 volt (c) 210 volt (d) 220 volt.
22. List two precautions to be taken to avoid overloading in the domestic circuit also state one difference between overloading and short-circuiting
23. Magnetic field lines are shown in the given diagram a student makes. A student makes a statement that the magnetic field at X is stronger than at Y. Justify this statement. Also, re-draw the diagram and mark the direction of magnetic field lines.
24. Explain briefly two different ways to induce a current in a coil. State the rule which determines the direction of induced current. A device for producing electric current is called
(a)Galvanometer (b) Motor (c) Generator (d) Ammeter.
25. Define electromagnetic induction two coils P and S are wound over the same iron core. Coil P is connected to battery and key and the coil S is connected to a galvanometer. Write your observations when:
(i) Current in the coil P is started by closing the key
(ii) The current continues to flow in coil P.
(iii) The current coil P is stopped by removing the key. Explain the reason for such observation.
26. Two coils of insulated copper wire are wound over a non-conducting cylinder as shown. Coil, I have a larger number of turns.
(i) Write your observations when :
(a) key K is closed (b) key K is opened.
Give the reason for your observation.
(ii) Mention the name of the phenomenon involved and define it.
(iii)Name of two coils used in this experiment.
27. Give one difference between the wires used in the element of an electric heater and in a fuse.
28. Two magnets are lying side by side as shown below. Draw magnetic field line between poles P and Q.
P Q
29. You are given a strong bar magnet and a magnetic compass needle. Describe an activity by which the magnetic field lines due to the bar magnet can be drawn.
30. (a) Explain two safety measures commonly used in electric circuits and appliances.
(b) An electron enters a magnetic field at right angles to it as shown in the figure. What will be the direction of force acting on the electron? State the rule which gives the direction of the force on the electron.
(c) If instead of the electron a neutron enters a field, what will be its direction of motion? Give reasons for your answer.
31. Describe briefly an activity to
(a) Demonstrate the pattern of magnetic field lines around a straight current-carrying conductor and
(b) Find the direction of the magnetic field produced for a given direction of current in the conductor.
(c) Name and state the rule to find the direction of the magnetic field around a straight current-carrying conductor. Draw a diagram to explain the same activity.
32. A stationary charge is placed in a magnetic field.
(a) Will it experience a force? Give reasons to justify your answer.
(b) On what factors does the direction of force experienced by a conductor when placed in a magnetic field depends?
(c) Under what conditions are the force experienced by a current-carrying conductor placed in a uniform magnetic field maximum.
(d) Name and state the rule which gives the direction of force by a current-carrying conductor placed in a magnetic field.
(d) Name and state the rule which gives the direction of force by a current-carrying conductor placed in a magnetic field.
33. An alternating current has a frequency of 50 Hz. How many times does it change its direction in one sec?
34. What is a solenoid? Draw magnetic field lines showing the magnetic field inside and outside the current-carrying solenoid? Mention two ways to increase the strength of the field of a solenoid.
35. How does the magnetic field produce around a straight current-carrying conductor change as :
(a) Current in the conductor increased?
(b) The distance from the conductor is decreased?
(c) The direction of the flow of current changes?.
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