Vardaan Learning Institute

Topic: Magnetic Effects of Electric Current

Class: 10 (Science) Type: Bonus Practice Paper Max. Marks: 50
Name:
Date:
SECTION A: OBJECTIVE TYPE QUESTIONS (1 Mark Each)
1. Magnetic field lines inside a current-carrying solenoid are:
  1. Parallel straight lines
  2. Curved lines
  3. Circular lines
  4. Zigzag lines
2. The direction of the force on a current-carrying conductor in a magnetic field is given by:
  1. Right Hand Thumb Rule
  2. Fleming's Left Hand Rule
  3. Fleming's Right Hand Rule
  4. Maxwell's Corkscrew Rule
3. Which wire has green insulation in a domestic circuit?
  1. Live wire
  2. Neutral wire
  3. Earth wire
  4. Fuse wire
4. The frequency of AC (Alternating Current) supply in India is:
  1. 0 Hz
  2. 50 Hz
  3. 60 Hz
  4. 100 Hz
5. What happens to the magnetic field at the center of a circular coil if the current is increased?
  1. It decreases
  2. It remains the same
  3. It increases
  4. It becomes zero
6. Ideally, a commercial electric motor uses:
  1. Permanent magnet
  2. Electromagnet
  3. Soft iron core only
  4. Steel core only
7. The strength of magnetic field inside a long current carrying straight solenoid is:
  1. More at the ends than at the center
  2. Minimum in the middle
  3. Same at all points
  4. Increases from one end to another
8. By which instrument can the presence of a magnetic field be determined?
  1. Ammeter
  2. Voltmeter
  3. Magnetic Needle
  4. Galvanometer
9. No two magnetic field lines interfere or cross each other because:
  1. They travel in parallel paths
  2. If they cross, there would be two directions of field at one point, which is impossible
  3. They originate from different points
  4. They have different strengths
10. The phenomenon of electromagnetic induction is:
  1. The process of charging a body
  2. The process of generating magnetic field due to current
  3. Producing induced current in a coil due to relative motion between a magnet and the coil
  4. The process of rotating a coil of an electric motor
Directions (Q11-Q14): In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:
  1. Both A and R are true and R is the correct explanation of A.
  2. Both A and R are true but R is not the correct explanation of A.
  3. A is true but R is false.
  4. A is false but R is true.
11. Assertion (A): A compass needle gets deflected when brought near a current carrying wire.
Reason (R): An electric current produces a magnetic field.
12. Assertion (A): Magnetic field lines do not intersect each other.
Reason (R): Magnetic field lines are imaginary lines.
13. Assertion (A): The strength of the magnetic field produced by a current carrying solenoid gets increased when a soft iron core is placed inside it.
Reason (R): Soft iron is a magnetic material so it increases the magnetic field.
14. Assertion (A): The metallic body of electrical appliances is connected to the earth wire.
Reason (R): It is a safety measure to prevent electric shock if the live wire touches the metallic body.
SECTION B: SHORT ANSWER QUESTIONS (3 Marks Each)
15. Draw the magnetic field lines around a bar magnet. List two characteristics of these lines.
16. What is the role of a fuse in an electric circuit? How does it work?
17. State the Right-Hand Thumb Rule. What does it determine?
18. What is an electromagnet? How does it differ from a permanent magnet?
19. Why is a series arrangement not used for domestic circuits? (Give two reasons).
20. What is the function of an earth wire? Why is it necessary to earth metallic appliances?
SECTION C: LONG ANSWER QUESTIONS (5 Marks Each)
21. (i) What is a solenoid? Draw the pattern of magnetic field lines of a current carrying solenoid.
(ii) Mention two ways to increase the strength of the magnetic field of a solenoid.
(iii) What happens if a soft iron core is placed inside the solenoid?
22. (i) Explain the phenomenon of Short Circuiting and Overloading in an electric circuit.
(ii) Determine the direction of the force acting on a proton moving towards the East in a magnetic field directed towards the North.
(iii) Name and state the rule used to find the direction of force in (ii).
SECTION D: CASE STUDY (4 Marks)
23. Read the following text and answer the questions:
Hans Christian Oersted, a Danish physicist, was the first to discover the connection between electricity and magnetism. He observed that a compass needle got deflected when current was passed through a wire placed nearby. This experiment confirmed that electric current produces a magnetic field.

(i) Which instrument is used to detect the presence of a magnetic field? (1 Mark)
(ii) What will happen to the deflection if the direction of current is reversed? (1 Mark)
(iii) State Fleming's Left Hand Rule. (2 Marks)
24. Read the following text and answer the questions:
In our homes, we receive electric power through a main supply (mains), either supported through overhead electric poles or by underground cables. One of the wires in this supply, usually with red insulation cover, is called the live wire (or positive). Another wire, with black insulation, is called the neutral wire (or negative). In our country, the potential difference between the two is 220 V.

(i) What is the colour of the live wire in an electric cable? (1 Mark)
(ii) What is the frequency of AC supply in India? (1 Mark)
(iii) What is the potential difference between live and neutral wires in India? Explain the function of the third wire (Earth wire) often found in such cables. (2 Marks)
"All the best!"