Vidaara.orgClass 7 · Mathematics
CodeVID-M7-WS
Electric Current and its Effects — 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 flow of electric charge through a conducting path is called:
- A.Voltage
- B.Electric current
- C.Resistance
- D.Frequency
2.
A bulb in a circuit glows only when the circuit is:
- A.Open
- B.Broken
- C.Closed (complete)
- D.Switched off
3.
In a circuit diagram, an ammeter is represented by a circle containing the letter:
- A.V
- B.A
- C.R
- D.C
4.
In a cell symbol, the positive terminal is shown by the:
- A.Short thick line
- B.Long thin line
- C.Circle with a cross
- D.Zig-zag line
5.
Standard circuit symbols are used in diagrams mainly because they are:
- A.Colourful
- B.Simple and standardised
- C.Realistic pictures
- D.Difficult to draw
6.
In a series circuit, the components are connected:
- A.On separate branches
- B.One after another in a single loop
- C.Across each other
- D.Without any wires
7.
If one bulb fuses in a series circuit, the other bulbs will:
- A.Glow brighter
- B.Keep glowing normally
- C.All stop glowing
- D.Glow dimmer
8.
Home wiring is usually done in a circuit of the type:
- A.Series
- B.Parallel
- C.Open
- D.Broken
9.
In a parallel circuit, the current has:
- A.Only one path
- B.More than one path
- C.No path
- D.A broken path
10.
Two identical bulbs glow brighter when connected in:
- A.Series
- B.Parallel
- C.An open circuit
- D.A broken circuit
11.
The production of heat when current flows through a wire is called the:
- A.Magnetic effect
- B.Heating effect
- C.Chemical effect
- D.Lighting effect
12.
The opposition offered by a material to the flow of current is called:
- A.Voltage
- B.Current
- C.Resistance
- D.Power
13.
The heating elements of appliances like irons and heaters are usually made of:
- A.Copper
- B.Nichrome
- C.Aluminium
- D.Silver
14.
An electric fuse protects a circuit by:
- A.Increasing the current
- B.Melting and breaking the circuit
- C.Storing charge
- D.Reflecting heat
15.
The filament of an electric bulb glows because it is made of a high-resistance metal called:
- A.Copper
- B.Tungsten
- C.Nichrome
- D.Iron
16.
An electric current flowing through a wire produces around it a:
- A.Magnetic field
- B.Sound wave
- C.Light beam
- D.Vacuum
17.
A coil of insulated wire wound on a soft iron core that acts as a magnet only when current flows is a(n):
- A.Permanent magnet
- B.Electromagnet
- C.Fuse
- D.Resistor
18.
The strength of an electromagnet can be increased by:
- A.Reducing the turns
- B.Increasing the current
- C.Removing the core
- D.Using less wire
19.
An electromagnet is preferred in a scrap-lifting crane because it can be:
- A.Made permanent
- B.Switched on and off
- C.Made of steel
- D.Used without current
20.
The discovery that a current deflects a nearby compass needle was made by:
- A.Newton
- B.Oersted
- C.Faraday
- D.Edison
21.
The electric bell works on the principle of the:
- A.Heating effect
- B.Electromagnet
- C.Chemical effect
- D.Reflection of sound
22.
In an electric bell, the part that is struck to produce sound is the:
- A.Armature
- B.Spring
- C.Gong
- D.Contact screw
23.
The bell rings continuously while the switch is pressed because of a:
- A.Single strike
- B.Make-and-break circuit
- C.Permanent magnet
- D.Open circuit
24.
The core of the electromagnet in a bell is made of soft iron because it:
- A.Stays magnetised always
- B.Magnetises and demagnetises quickly
- C.Never becomes magnetic
- D.Conducts no current
25.
When the switch of an electric bell is released, the bell:
- A.Rings louder
- B.Keeps ringing
- C.Falls silent
- D.Heats up
Answer Key
Section A — Multiple Choice (1 mark each)
- (B) Electric current
- (C) Closed (complete)
- (B) A
- (B) Long thin line
- (B) Simple and standardised
- (B) One after another in a single loop
- (C) All stop glowing
- (B) Parallel
- (B) More than one path
- (B) Parallel
- (B) Heating effect
- (C) Resistance
- (B) Nichrome
- (B) Melting and breaking the circuit
- (B) Tungsten
- (A) Magnetic field
- (B) Electromagnet
- (B) Increasing the current
- (B) Switched on and off
- (B) Oersted
- (B) Electromagnet
- (C) Gong
- (B) Make-and-break circuit
- (B) Magnetises and demagnetises quickly
- (C) Falls silent
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