Vidaara.orgClass 8 · Mathematics
CodeVID-M8-WS
Magnetism and Electromagnetism — Practice Worksheet
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Choose the correct option (A, B, C or D) for each question.
- The answer key is at the end — try the paper first!
Section A — Multiple Choice (1 mark each)
25 × 1 = 25 marks
1.
The region around a magnet where its force can be detected is the:
- A.Electric field
- B.Magnetic field
- C.Gravitational field
- D.Pole
2.
Like poles of two magnets:
- A.Attract
- B.Repel
- C.Do nothing
- D.Melt
3.
Outside a magnet, magnetic field lines point from the:
- A.South to north pole
- B.North to south pole
- C.East to west
- D.Top to bottom
4.
A magnetic field is strong where the field lines are:
- A.Far apart
- B.Crowded close together
- C.Crossing
- D.Straight
5.
Two magnetic field lines can never:
- A.Be curved
- B.Cross each other
- C.Form loops
- D.Point to a pole
6.
Oersted's experiment showed that an electric current produces a:
- A.Sound
- B.Magnetic field
- C.Light beam
- D.Vacuum
7.
In Oersted's experiment, the compass needle was ______ when current flowed.
- A.Melted
- B.Deflected
- C.Destroyed
- D.Cooled
8.
The magnetic field lines around a straight current-carrying wire are:
- A.Straight lines
- B.Concentric circles
- C.Squares
- D.Triangles
9.
The rule used to find the direction of the field around a wire is the:
- A.Ohm's law
- B.Right-hand thumb rule
- C.Pascal's law
- D.Snell's law
10.
The magnetic field around a wire is stronger when the current is:
- A.Smaller
- B.Larger
- C.Zero
- D.Reversed only
11.
A coil of many circular turns of insulated wire wound like a cylinder is a:
- A.Resistor
- B.Solenoid
- C.Fuse
- D.Capacitor
12.
The magnetic field of a current-carrying solenoid is similar to that of a:
- A.Straight wire
- B.Bar magnet
- C.Battery
- D.Bulb
13.
An electromagnet is made by winding a coil around a core of:
- A.Soft iron
- B.Wood
- C.Plastic
- D.Glass
14.
An electromagnet loses its magnetism when the:
- A.Current is switched off
- B.Coil is added
- C.Core is iron
- D.Turns increase
15.
Which of these increases the strength of an electromagnet?
- A.Fewer turns
- B.Increasing the current
- C.Removing the core
- D.Reducing the current
16.
A current-carrying conductor placed in a magnetic field experiences a:
- A.Force
- B.Sound
- C.Smell
- D.Colour change
17.
The direction of the force on a current-carrying conductor is given by:
- A.Right-hand thumb rule
- B.Fleming's left-hand rule
- C.Ohm's law
- D.Snell's law
18.
In Fleming's left-hand rule, the thumb represents the:
- A.Field
- B.Current
- C.Force (motion)
- D.Resistance
19.
An electric motor converts electrical energy into ______ energy.
- A.Sound
- B.Mechanical (kinetic)
- C.Chemical
- D.Light
20.
The split ring that reverses the current each half turn in a DC motor is the:
- A.Brush
- B.Commutator
- C.Armature
- D.Magnet
21.
The production of a current in a coil by a changing magnetic field is called:
- A.Conduction
- B.Electromagnetic induction
- C.Reflection
- D.Electrolysis
22.
A current is induced in a coil only when the magnetic field through it is:
- A.Constant
- B.Changing
- C.Zero
- D.Removed completely
23.
An electric generator converts ______ energy into electrical energy.
- A.Chemical
- B.Mechanical (kinetic)
- C.Sound
- D.Light
24.
A transformer that increases the voltage is a:
- A.Step-down transformer
- B.Step-up transformer
- C.Motor
- D.Generator
25.
The transformer relation between voltage and turns is:
- A.Vₚ/Vₛ = Nₚ/Nₛ
- B.V = IR
- C.P = VI
- D.F = ma
Answer Key
Section A — Multiple Choice (1 mark each)
- (B) Magnetic field
- (B) Repel
- (B) North to south pole
- (B) Crowded close together
- (B) Cross each other
- (B) Magnetic field
- (B) Deflected
- (B) Concentric circles
- (B) Right-hand thumb rule
- (B) Larger
- (B) Solenoid
- (B) Bar magnet
- (A) Soft iron
- (A) Current is switched off
- (B) Increasing the current
- (A) Force
- (B) Fleming's left-hand rule
- (C) Force (motion)
- (B) Mechanical (kinetic)
- (B) Commutator
- (B) Electromagnetic induction
- (B) Changing
- (B) Mechanical (kinetic)
- (B) Step-up transformer
- (A) Vₚ/Vₛ = Nₚ/Nₛ
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