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السلام عليكم ،

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اللون الاحمر هو الاجابه

1. True or False?

(a) From the definition of capacitance C 5 Q /DV, it follows that an uncharged capacitor has a capaci- tance of zero.
False
(b) As described by the definition of capaci- tance, the potential difference across an uncharged capacitor is zero.
True


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2. By what factor is the capacitance of a metal sphere multi-
plied if its volume is tripled? (a) 3 (b) 31/3 (c) 1 (d) 321/3
(e) 1

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3. An electronics technician wishes to construct a parallel- plate capacitor using rutile (k 5 100) as the dielectric. The area of the plates is 1.00 cm2. What is the capacitance if the rutile thickness is 1.00 mm? (a) 88.5 pF (b) 177 pF (c) 8.85 mF (d) 100 mF (e) 35.4 mF


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4. A capacitor with very large capacitance is in series with another capacitor with very small capacitance. What is the equivalent capacitance of the combination? (a) slightly greater than the capacitance of the large capacitor (b) slightly less than the capacitance of the large capaci- tor (c) slightly greater than the capacitance of the smallcapacitor (d) slightly less than the capacitance of the small capacitor



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5. If three unequal capacitors, initially uncharged, are connected in series across a battery, which of the follow- ing statements is true? (a) The equivalent capacitance is greater than any of the individual capacitances. (b) The largest voltage appears across the smallest capacitance. (c) The largest voltage appears across the largest capaci- tance. (d) The capacitor with the largest capacitance has the greatest charge. (e) The capacitor with the smallest capacitance has the smallest charge.

احترت بين b و d و e

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7- (i) What happens to the magnitude of the charge on each plate of a capacitor if the potential difference between the conductors is doubled? (a) It becomes four times larger. (b) It becomes two times larger. (c) It is unchanged. (d) It becomes one-half as large. (e) It becomes one-fourth as large. (ii) If the potential difference across a capacitor is doubled, what happens to the energy stored? Choose from the same possibilities as in part (i).

i ) b
ii ) a


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8. A parallel-plate capacitor is connected to a battery. What happens to the stored energy if the plate separation is dou- bled while the capacitor remains connected to the battery? (a) It remains the same. (b) It is doubled. (c) It decreases by a factor of 2. (d) It decreases by a factor of 4. (e) It increases by a factor of 4.

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9. A parallel-plate capacitor is charged and then is discon- nected from the battery. By what factor does the stored energy change when the plate separation is then doubled? (a) It becomes four times larger. (b) It becomes two times larger. (c) It stays the same. (d) It becomes one-half as large. (e) It becomes one-fourth as large


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11. A parallel-plate capacitor filled with air carries a charge Q. The battery is disconnected, and a slab of material with dielectric constant k 5 2 is inserted between the plates. Which of the following statements is true? (a) The voltage across the capacitor decreases by a factor of 2. (b) The volt- age across the capacitor is doubled. (c) The charge on the plates is doubled. (d) The charge on the plates decreases by a factor of 2. (e) The electric field is doubled.


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13. A fully charged parallel-plate capacitor remains connected to a battery while you slide a dielectric between the plates. Do the following quantities (a) increase, (b) decrease, or (c) stay the same? (i) C (ii) Q (iii) DV (iv) the energy stored in the capacitor

i ) (a) increase
ii ) (a) increase
iii ) (c) stay the same
iv ) (a) increase



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You charge a parallel-plate capacitor, remove it from the battery, and prevent the wires connected to the plates from touching each other. When you increase the plate separa- tion, do the following quantities (a) increase, (b) decrease, or (c) stay the same? (i) C (ii) Q (iii) E between the plates (iv)DV

i ) (a) increase
ii ) (c) stay the same
iii ) (b) decrease
iv ) (b) decrease


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١- مكثف متوازي اللوحين مشحون تم فصله من البطاريه
٢- مكثف مشحون متوازي اللوحين يبقا متصل ببطاريه

من حيث ( السعه - فرق الجهد - الشحنه - الطاقه - المجال الكهربائي )
ايهما يزيد او ينقص او يبقا ثابت ؟