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ساکن برقیات اور کپیسیٹر
7 سوالات: ایم ڈی کیٹ طبیعیات، جوابات اور وضاحت کے ساتھ۔
جوابی کنجی کے ساتھ قابلِ پرنٹ ورک شیٹ
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What is the force between two point charges of 1 microcoulomb each, placed 1 m apart in air? (k = 9 x 10⁹ N m²/C²)
- 1 0.9 N
- 2 9 x 10⁻⁶ N
- 3 9 N
- 4 9 x 10⁻³ N
جواب دیکھیں
درست جواب: 9 x 10⁻³ N
F = k q₁ q₂ / r² = 9 x 10⁹ x 10⁻⁶ x 10⁻⁶ / 1 = 9 x 10⁻³ N.
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What is the electric potential at 3 m from a point charge of 1 microcoulomb? (k = 9 x 10⁹ N m²/C²)
- 1 3000 V
- 2 27000 V
- 3 300 V
- 4 9000 V
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If the separation between the plates of a parallel plate capacitor is halved, its capacitance:
- 1 Halves
- 2 Stays the same
- 3 Doubles
- 4 Becomes four times as large
جواب دیکھیں
درست جواب: Doubles
C = epsilon x A / d, so capacitance is inversely proportional to the separation.
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Inserting a dielectric between the plates of a capacitor (battery disconnected or connected) makes its capacitance:
- 1 Increase
- 2 Decrease
- 3 Zero
- 4 Unchanged
جواب دیکھیں
درست جواب: Increase
A dielectric reduces the effective field between the plates and so raises the capacitance by the factor k.
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A 3 microfarad and a 6 microfarad capacitor are connected in parallel. What is the total capacitance?
- 1 9 microfarad
- 2 4.5 microfarad
- 3 2 microfarad
- 4 18 microfarad
جواب دیکھیں
درست جواب: 9 microfarad
In parallel, capacitances add: 3 + 6 = 9 microfarad.
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One volt is equal to one:
- 1 Joule per coulomb
- 2 Ampere per ohm
- 3 Newton per metre
- 4 Coulomb per joule
جواب دیکھیں
درست جواب: Joule per coulomb
Potential difference is energy per unit charge, so 1 V = 1 J/C.
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A potential difference of 100 V is applied across two plates 0.02 m apart. What is the electric field between them?
- 1 2 V/m
- 2 500 V/m
- 3 5000 V/m
- 4 2000 V/m