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7 سوالات: ایم ڈی کیٹ طبیعیات، جوابات اور وضاحت کے ساتھ۔
What is the force between two point charges of 1 microcoulomb each, placed 1 m apart in air? (k = 9 x 10^9 N m2/C2)
درست جواب: 9 x 10^-3 N
F = kq1q2 / r^2 = 9 x 10^9 x 10^-6 x 10^-6 / 1 = 9 x 10^-3 N.
What is the electric potential at 3 m from a point charge of 1 microcoulomb? (k = 9 x 10^9 N m2/C2)
If the separation between the plates of a parallel plate capacitor is halved, its capacitance:
درست جواب: Doubles
C = epsilon x A / d, so capacitance is inversely proportional to the separation.
Inserting a dielectric between the plates of a capacitor (battery disconnected or connected) makes its capacitance:
درست جواب: Increase
A dielectric reduces the effective field between the plates and so raises the capacitance by the factor k.
A 3 microfarad and a 6 microfarad capacitor are connected in parallel. What is the total capacitance?
درست جواب: 9 microfarad
In parallel, capacitances add: 3 + 6 = 9 microfarad.
One volt is equal to one:
درست جواب: Joule per coulomb
Potential difference is energy per unit charge, so 1 V = 1 J/C.
A potential difference of 100 V is applied across two plates 0.02 m apart. What is the electric field between them?