EASY
Upper Secondary: IGCSE
IMPORTANT
Earn 100

Use the idea of resistors in series to explain why a long wire has more resistance than a short wire (of the same thickness and material).

Important Questions on Electric Circuits

EASY
Upper Secondary: IGCSE
IMPORTANT
Cambridge IGCSE® Physics Coursebook Second Edition>Chapter 19 - Electric Circuits>Questions>Q 19.1

Use the idea of resistors in parallel to explain why a thick wire has less resistance than a thin wire (of the same length and material).

MEDIUM
Upper Secondary: IGCSE
IMPORTANT
Cambridge IGCSE® Physics Coursebook Second Edition>Chapter 19 - Electric Circuits>Questions>Q 19.12
What will be the effective resistance of three 60 Ω resistors connected together in parallel?
MEDIUM
Upper Secondary: IGCSE
IMPORTANT
Cambridge IGCSE® Physics Coursebook Second Edition>Chapter 19 - Electric Circuits>Questions>Q 19.13
Two resistors of values 30 Ω and 60 Ω are connected in parallel. Calculate their effective resistance.
MEDIUM
Upper Secondary: IGCSE
IMPORTANT
Cambridge IGCSE® Physics Coursebook Second Edition>Chapter 19 - Electric Circuits>Questions>Q 19.18
In normal use, a current of 3.5 A flows through a hairdryer. Choose a suitable fuse from the following: 3 A, 5 A, 13 A, 30 A. Explain your choice.
MEDIUM
Upper Secondary: IGCSE
IMPORTANT
Cambridge IGCSE® Physics Coursebook Second Edition>Chapter 19 - Electric Circuits>Questions>Q 19.19
Why are fuses fitted in the fuse box of a domestic electricity supply?
MEDIUM
Upper Secondary: IGCSE
IMPORTANT
Cambridge IGCSE® Physics Coursebook Second Edition>Chapter 19 - Electric Circuits>Questions>Q 19.19
What device could be used in place of the fuses?
MEDIUM
Upper Secondary: IGCSE
IMPORTANT
Cambridge IGCSE® Physics Coursebook Second Edition>Chapter 19 - Electric Circuits>Questions>Q 19.2
What hazards can arise when the current flowing in an electrical wire is too high?
HARD
Upper Secondary: IGCSE
IMPORTANT
Cambridge IGCSE® Physics Coursebook Second Edition>Chapter 19 - Electric Circuits>End-of-chapter questions>Q 1
Copy the table and complete it by adding names and symbols of the devices described.
Name of the device Circuit symbol Description
    Resistance decreases when light falls on it.
    Resistance changes when temperature changes.
    An electromagnetic switch.