A parallel plate capacitor with plate separation d is connected to a battery. Th

Question

A parallel plate capacitor with plate separation d is connected to a battery. The capacitor is fully charged to Q Coulombs and a voltage of V. (C is the capacitance and U is the stored energy.) Answer the following questions regarding the capacitor charged by a battery. For each statement below, select True or False.

True False  With the capacitor connected to the battery, inserting a dielectric with will decrease C.
True False  After being disconnected from the battery, decreasing d increases C.
True False  With the capacitor connected to the battery, decreasing d decreases Q.
True False  After being disconnected from the battery, inserting a dielectric with will increase V.
True False  After being disconnected from the battery, inserting a dielectric with will increase U.
True False  After being disconnected from the battery, decreasing d increases U.

Explanation / Answer

a)

false

this is false because after inserting a dielectric with k will increase C

b)

it is true

when d is decreasing the C will increase

c)

false

that increases C. V is fixed, so Q = CV, Q increases

d)

false

when dielectric will insert the C will increase and V will decrease

e)

false

increasing k means C increases. Q is constant, so V = Q/C decreases.

U = ½CV² = ½QV = ½Q²/C Energy in a cap in Joules. Picking one with only one changing variable,
U = ½QV. Q is constant and V decreases, so energy decreases

f)

true

Decreasing d increases C. Voltage is constant, so Q = CV, Q increases

U = ½CV² = ½QV = ½Q²/C Energy in a cap in Joules. Picking one with only one changing variable,
U = ½CV², with V constant, increasing C increases U

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.