Key relationship
C=κε₀A/d; Q=CV.
Physics · Class 12
Parallel-plate capacitance
Increase area or permittivity to store more charge per volt. Increase gap to reduce capacitance. Connected and isolated cases obey different charge constraints.
Open the interactive experiment →Parallel-plate capacitance
தட்டு பரப்பும் மின்காப்பு மாறிலியும் அதிகரித்தால் தேக்கத்திறன் அதிகரிக்கும். இடைவெளி அதிகரித்தால் குறையும்.
Key notes, relationships and model limits
Remember
Increase area or permittivity to store more charge per volt. Increase gap to reduce capacitance. Connected and isolated cases obey different charge constraints.
Common trap
Capacitance describes geometry and dielectric material. The relation Q = CV does not make C increase just because V increases.
Model limits
Parallel plates with area large compared with gap²; homogeneous dielectric and negligible fringing.
What you will learn
Use the controls and plotted relation to explain parallel-plate capacitance.
Try the experiment
Try both scenarios, change one control, and predict the result before checking the graph and readouts.
Think of it this way
Change one input while keeping the others fixed, as you would in a controlled experiment.
Worked example
For A=100 cm², d=1 mm and κ=4, C≈0.354 nF.
Why this matters
The model connects parallel-plate capacitance with an observable reading. Check the equation and assumptions before applying it.
Before you start
SI units · algebra · graph reading
Check your understanding
Doubling the plate gap while all other geometry is fixed does what to C?
- It doubles the capacitance.
- It halves the capacitance.
- It leaves capacitance unchanged.
Read the explanation
It halves the capacitance.
Course connection: Class XII Chapter 2. Consult the roadmap for CBSE, NEET, JEE Main and Advanced scope.