Class 12 Electrostatic Potential and Capacitance worksheet

Sample questions

Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.

Section A · multiple choice

1. 1.

   The potential 15 cm from a point charge of −2 μC is: (k = 9 × 10⁹ N m²/C²)

   1. 1.2 × 10⁵ V
   2. −8 × 10⁵ V
   3. −1,200 V
   4. −1.2 × 10⁵ V

   Answer

   (d) −1.2 × 10⁵ V

   V = kq/r

2. 2.

   The work needed to carry a charge of 9 μC from a point at 470 V to a point at 500 V is:

   1. 2.7 × 10⁻⁴ J
   2. −2.7 × 10⁻⁴ J
   3. 8.73 × 10⁻³ J
   4. 0.27 J

   Answer

   (a) 2.7 × 10⁻⁴ J

   W = q(V_B − V_A) = 9 × 10⁻⁶ × (30)

3. 3.

   The equivalent capacitance of 1 μF, 10 μF joined in series is:

   1. 10 μF
   2. 11 μF
   3. 0.91 μF
   4. 1.82 μF

   Answer

   (c) 0.91 μF

   1/C = Σ 1/Cᵢ

Section B · short answer

1. 4.

   Charges of −2 μC and −8 μC are at x = 0 and x = 24 cm. Find the potential at x = 16 cm. (k = 9 × 10⁹ N m²/C²)

   Answer

   −1.0125 × 10⁶ V

   V = k(q₁/r₁ + q₂/r₂), with r₁ = 16 cm and r₂ = 8 cm

2. 5.

   9 μF and 5 μF capacitors in parallel are joined in series with a 7 μF capacitor across 190 V. Find the equivalent capacitance and the charge on the 7 μF capacitor.

   Answer

   4.67 μF; 8.87 × 10⁻⁴ C

   parallel pair 14 μF; series with 7 μF; Q = CV

Section C · long answer

1. 6.

   11 μF and 12 μF capacitors in series are joined in parallel with 8 μF; this group is in series with 11 μF, across 160 V. Find the equivalent capacitance, the total charge and the energy stored.

   Answer

   6.11 μF; 9.77 × 10⁻⁴ C; 0.0782 J

   group = 5.74 + 8 = 13.74 μF

Fresh sheets for your child

In the app, every Electrostatic Potential and Capacitance sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.

Coming soon for Android and iPhone.

More Class 12 Physics