Concept explainers
(a)
The new capacitance of a capacitor when it is changed to make an ultracapacitor.
Answer to Problem 92QAP
New capacitance of the capacitor will increase
Explanation of Solution
Given:
Initial value of capacitance of a normal capacitor =
Relation between area of plate of ultra-capacitor and normal capacitor,
Relation between distances for ultra-capacitor and normal capacitor,
Formula used:
Capacitance of the parallel plate capacitor is defined as,
Calculation:
Area of ultra-capacitor =
Separation of plates for ultra-capacitor =
Capacitance of ultra-capacitor =
Then,
Conclusion:
Thus, capacitance of the ultra-capacitor is
(b)
The energy stored in ultra-capacitor when it is charged to
Answer to Problem 92QAP
The energy stored in ultra-capacitor is
Explanation of Solution
Given:
Potential difference =
Capacitance of ultra-capacitor =
Capacitance of normal capacitor =
Formula used:
Energy stored in the capacitor is defined as,
Calculation:
The energy stored in the ultra-capacitor,
Energy stored in normal capacitor,
Now,
Conclusion:
Thus, energy stored in the ultra-capacitor is
(c)
The comparison the energy stored in ultra-capacitor and the energy stored in the AAA battery.
Answer to Problem 92QAP
The energy stored in ultra-capacitor is
Explanation of Solution
Given:
Energy stored in the ultra-capacitor =
Energy stored in the AAA battery =
Calculation:
Thus, from above discussion, we find that the energy stored in ultra-capacitor is
(d)
The resistance in the wire of the circuit when ultra-capacitor is discharged.
Answer to Problem 92QAP
The resistance in the wire of the circuit is
Explanation of Solution
Given:
Time interval =
Formula used:
Charge on the ultra-capacitor at time t,
Discharging of charge in capacitor in CR circuit is defined as,
Calculation:
From above formula,
Conclusion:
So, the resistance in the wire while capacitor is discharged is
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Chapter 18 Solutions
COLLEGE PHYSICS,VOLUME 1
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