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9 سوالات: بارہویں جماعت طبیعیات، جوابات اور وضاحت کے ساتھ۔
جوابی کنجی کے ساتھ قابلِ پرنٹ ورک شیٹ
Two point charges of 2 microcoulomb and 3 microcoulomb are 3 m apart in air. The force between them is about: (k = 9 x 10⁹ N m²/C²)
درست جواب: 6 x 10⁻³ N
F = k q₁ q₂ / r² = 9 x 10⁹ x 6 x 10⁻¹² / 9 = 6 x 10⁻³ N.
The electric field inside a charged conductor in equilibrium is:
درست جواب: Zero
Free charges rearrange until the field inside is zero.
The SI unit of electric field is:
درست جواب: N/C
Field is force per unit charge, newton per coulomb (or volt per metre).
Two plates of a capacitor are 2 mm apart with a potential difference of 100 V. The field between them is:
Capacitors in parallel have a combined capacitance equal to:
درست جواب: The sum of the capacitances
For parallel capacitors C = C₁ + C₂ + ...
Gauss's law relates the electric flux through a closed surface to the:
The energy stored in a capacitor of capacitance C charged to voltage V is:
A dielectric placed between capacitor plates:
درست جواب: Increases the capacitance
It reduces the field and raises capacitance.
The electric potential at a point is the work done per unit charge in bringing a:
درست جواب: Positive test charge from infinity
This is the definition of potential.