Concept explainers
(a)
ToCalculate: The energy stored in the capacitor.
(a)
Answer to Problem 85P
Explanation of Solution
Given information :
Charge of an electrically isolated capacitor
Distance between plated
Lengths of capacitor plates
Formula used :
Energy stored in capacitor is:
Where, Q is the charge stored and C is the capacitance of the capacitor.
Equivalent capacitance of parallel plate capacitor:
Calculation:
The energy stored in the capacitor as a function of the equivalent capacitance
The capacitances of the two capacitors are,
And
Conclusion:
The energy stored in the capacitor is,
(b)
ToCalculate: The force by examining how the stored energy varies with x .
(b)
Answer to Problem 85P
Explanation of Solution
Given information:
Charge of an electrically isolated capacitor
Distance between plated
Lengths of capacitor plates
Energy stored in the capacitor,
Formula used:
Electric force:
U is the energy stored.
Calculation:
Conclusion:
The force by examining how the stored energy varies with x is,
(c)
ToCalculate: The force in terms of the capacitance and potential difference V between the plates.
(c)
Answer to Problem 85P
Explanation of Solution
Given information :
Charge of an electrically isolated capacitor
Distance between plated
Lengths of capacitor plates
Formula Used:
The capacitance can be obtained by:
Where,
Charge stored in capacitor,
Where, C is the capacitance and V is the voltage.
Calculation:
Multiply and divide by
This expression is independent of x.
Conclusion:
The force in terms of the capacitance and potential difference V between the plates is,
(d)
ToFind: The position from where the force originates.
(d)
Answer to Problem 85P
The force originates from the fringing fields around the edges of the capacitor.
Explanation of Solution
Introduction:
The fringe field is the magnetic field at the edge. It occurs outside the center of the magnet. This depends on the magnet’s core.
The force originates from the condenser edges of fringing fields. The effect of force is to draw the polarized dielectric in between the plates of the condenser.
Conclusion:
Hence, the force originates from the fringing fields around the edges of the capacitor.
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Chapter 24 Solutions
EBK PHYSICS FOR SCIENTISTS AND ENGINEER
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