🌟 Class
7 Science Curiosity – Chapter 3 Solutions
⚡ Electricity: Circuits
and their Components | Amresh Academy
📝 🔹 Let Us
Enhance Our Learning
1. Choose the incorrect statement.
2. Observe Fig. 3.16. With which material
connected between the ends A and B, the lamp will not glow?
3. In Fig. 3.17, if the filament of one of the
lamps is broken, will the other glow? Justify your answer.
4. A student forgot to remove the insulator
covering from the connecting wires while making a circuit. If the lamp and the
cell are working properly, will the lamp glow?
5. Draw a circuit diagram for a simple torch
using symbols for electric components.
6. In Fig. 3.18:
7. Vidyut has made the circuit as shown in Fig.
3.19. Even after closing the circuit, the lamp does not glow. What can be the
possible reasons? List as many possible reasons as you can for this faulty
operation. What will you do to find out why the lamp did not glow?
👉 Answer:
Possible reasons:
- Fused
bulb 💡❌
- Dead
cell 🔋
- Loose
connection
- Broken
wire
- Faulty
switch
- Wrong
polarity
- Insulation
not removed
8. In Fig. 3.20, in which case(s) the lamp will
not glow when the switch is closed?
9. Suppose the ‘+’ and ‘-‘ symbols cannot be
read on a battery. Suggest a method to identify the two terminals of this
battery.
10. You are given six cells marked A, B, C, D,
E, and F. Some of these are working and some are not. Design an activity to
identify which of them are working. (i) List the items that you require. (ii)
Write the procedure that you will follow. (iii) With the items, carry out the
activity to identify the cells that are working.
👉 Answer:
(i) Items → bulb 💡, wires 🔌
(ii) Procedure:
- Make
circuit
- Insert
one cell
- Check
glow
11. An LED requires two cells in series to glow.
Tanya made the circuit as shown in Fig. 3.21. Will the lamp glow? If not, draw
the wires for correct connections.
👉
Correct connection:
- Cells
→ +
to – 🔋
- LED
→
correct polarity
✍️ 🔹 Very
Short Answer Type Questions
What is the function of a switch in an electric
circuit?
👉
Completes or breaks circuit 🔘
What does an electric cell provide to a circuit?
👉
Electrical energy 🔋
Name the two terminals of a cell.
👉
Positive (+) & Negative (–)
Why does an LED glow only in one direction?
👉
Current flows in one direction ⚡
What is a filament in an incandescent lamp?
👉 Thin
glowing wire 💡
🧠 🔹 Short
Answer Type Questions
Why is it important to connect electric cells in
a particular order in a torch?
👉 Series
connection ensures proper current 🔋
What happens when the filament of an
incandescent lamp breaks?
👉 Lamp
becomes fused ❌
What do we mean by an electrical circuit?
👉
Complete path of current 🔄
Why are wires covered with plastic or rubber?
👉 Safety
(insulation) 🛡️
How can you identify the terminals of a battery
if the symbols are not visible?
👉 Using
LED or holder ✔️
📖 🔹
Descriptive Answer Type Questions
Why do LEDs need to be connected correctly in a
circuit?
👉 Work
only in one direction
Explain the difference between conductors and
insulators with examples.
Why is copper commonly used for making wires and
not gold or silver?
👉 Cheap
+ good conductor
What is a circuit diagram and why is it used?
👉
Symbolic representation 📐
How does a homemade switch work in a circuit?
🚀 🔹
Exploring Questions
Why is it dangerous to use damaged wires or
switches?
👉
Electric shock ⚠️
How would you test whether a cell is working or
not using a simple circuit?
👉 Use
bulb test 💡
If electricity is unavailable in your home for
two days, list five daily tasks that would be affected.
👉 Light,
phone, fridge, TV, water pump
Why do LEDs last longer and are more efficient
than incandescent lamps?
👉 Less
energy, no filament ⚡
Design an activity using a conduction tester to
test if a material is a conductor or insulator.
0 Comments