Coulombs Law and Electric Field

⏱ Time: 0s

Q1. What is the potential difference across a capacitor of 5 µF charged with 0.01 C?

Solution:

V = Q / C = 0.01 C / 5 x 10^-6 F = 2000 V.

⏱ Time: 0s

Q2. What is the electric field between two parallel plates separated by 0.1 m with a potential difference of 100 V?

Solution:

E = V/d = 100 V / 0.1 m = 1000 N/C.

⏱ Time: 0s

Q3. What is the electric field due to a point charge of -4 µC at a distance of 0.25 m?

Solution:

E = k * |q| / r^2 = (8.99 x 10^9 N m²/C²) * (4 x 10^-6 C) / (0.25 m)^2 = -5760 N/C.

⏱ Time: 0s

Q4. If the electric potential at a point is 100 V and the charge at that point is 2 µC, what is the electric potential energy?

Solution:

Potential energy U = V * q = 100 V * 2 x 10^-6 C = 0.0002 J = 0.2 J.

⏱ Time: 0s

Q5. What is the capacitance of a capacitor that stores 0.01 C of charge at a potential difference of 5 V?

Solution:

C = Q / V = 0.01 C / 5 V = 0.002 F.

⏱ Time: 0s

Q6. If two capacitors of 4 µF and 6 µF are connected in series, what is the total capacitance?

Solution:

1/C_total = 1/C1 + 1/C2 = 1/4 + 1/6 = 5/12, thus C_total = 12/5 = 2.4 µF.

⏱ Time: 0s

Q7. What is the capacitance of a capacitor that stores 20 µC of charge at a potential difference of 5 V?

Solution:

C = Q/V = 20 x 10^-6 C / 5 V = 4 µF.

⏱ Time: 0s

Q8. What is the electric potential at a point 1 m away from a +1 C charge?

Solution:

Electric potential V = k * q / r = (8.99 x 10^9 N m²/C²) * (1 C) / (1 m) = 8.99 V.

⏱ Time: 0s

Q9. In a parallel circuit with a total voltage of 12 V, what is the voltage across each resistor?

Solution:

In a parallel circuit, the voltage across each resistor is equal to the total voltage, so it is 12 V.

⏱ Time: 0s

Q10. What is the equivalent resistance of three 4 Ω resistors in series?

Solution:

R_eq = R1 + R2 + R3 = 4 Ω + 4 Ω + 4 Ω = 12 Ω.