Section A: Fill in the Blanks (10)

1. The magnetic effect of electric current was discovered by ____________________.
2. A temporary magnet produced by electric current is called an ____________________.
3. The heating element of an electric iron is usually made of ____________________.
4. A ____________________ protects electrical appliances from excessive current.
5. Electric current flowing through a wire produces a ____________________ field around it.
6. The SI unit of electric current is ____________________.
7. A compass needle deflects because of the ____________________ effect of electric current.
8. The wire used in heating appliances has ____________________ resistance.
9. An electric bell works using an ____________________.
10. The heating effect of electric current is also called the ____________________ effect.

Section B: True / False (10)

1. Electric current produces a magnetic field around a conductor.
2. An electromagnet remains magnetic even after switching off the current.
3. Nichrome is used for making heating elements.
4. A fuse should have a low melting point.
5. Copper is commonly used as the heating element in electric irons.
6. Electric bells work using the magnetic effect of electric current.
7. More turns in an electromagnet make it stronger.
8. Heating appliances convert electrical energy into heat energy.
9. A compass needle can detect a magnetic field.
10. Excess current can damage electrical appliances.

Section C: Short Answer Questions (10)

1. What is the magnetic effect of electric current?
2. What is an electromagnet?
3. Why is nichrome used for making heating elements?
4. State any four uses of electromagnets.
5. Explain the working of an electric bell.
6. What is the function of a fuse?
7. How can the strength of an electromagnet be increased?
8. Differentiate between a permanent magnet and an electromagnet.
9. Why does a compass needle deflect near a current-carrying conductor?
10. Mention any four electrical appliances that work on the heating effect of electric current.

Class 8 CBSE Mathematics

Chapter: Quadrilaterals

Short Answer Questions (2–3 Marks)

1. Define a quadrilateral. Name its different types with one example of each.

2. What is the sum of the interior angles of a quadrilateral? Explain how it is obtained.

3. State any four properties of a parallelogram.

4. Differentiate between a rectangle and a square on the basis of their properties.

5. State the properties of the diagonals of a rhombus.

6. Explain why every square is a rectangle but every rectangle is not a square.

7. A quadrilateral has three angles measuring 80°, 95°, and 105°. Find the fourth angle.

8. State any four properties of a trapezium. How is an isosceles trapezium different from a trapezium?

9. Explain the difference between a kite and a rhombus.

10. The angles of a quadrilateral are in the ratio 2 : 3 : 4 : 7. Find all its angles.

Long Answer Questions (4–5 Marks)

1. Compare the properties of a parallelogram, rectangle, rhombus, and square. Present your answer in a tabular form.

2. Explain the properties of the diagonals of the following quadrilaterals with neat labelled diagrams:

• Parallelogram
• Rectangle
• Rhombus
• Square

3. Draw neat labelled figures of a parallelogram, rectangle, rhombus, square, trapezium, and kite. Write at least four properties of each quadrilateral and compare their similarities and differences.

4. A quadrilateral has sides of lengths 8 cm, 10 cm, 8 cm, and 10 cm. Its diagonals bisect each other at right angles. Identify the quadrilateral. Justify your answer by stating its properties.