The following statements are advantages of a solid dielectric material between the plates of a capacitor except that

Analyze the question: We need the statement that is NOT an advantage of placing a solid dielectric between capacitor plates.

Concept: A dielectric is an insulator. Placing it between the plates of a capacitor:

• Increases capacitance, since C = εᵣε₀A/d, where εᵣ > 1 for a dielectric, so C is greater than in a vacuum.
• Increases the breakdown voltage, because the dielectric strength is higher than that of air or a vacuum. The capacitor can withstand a higher potential difference before it breaks down.
• Keeps the plates rigidly apart at a fixed separation d, which prevents them from touching or shorting.
• Does not conduct, because it is an insulator. Its job is to prevent charge from flowing between the plates.

Checking each option:

• A. The maximum p.d. the capacitor can withstand increases. This is true and is an advantage.
• B. It increases the electrical conduction of the capacitor. This is false. A good dielectric has very high resistivity and reduces conduction (leakage) between the plates. Conduction through the dielectric would be a disadvantage, since it would discharge the capacitor.
• C. The capacitance is much greater than with a vacuum. This is true and is an advantage.
• D. It keeps the plates at a fixed separation. This is true and is an advantage.

Exam tip: In "except" questions, find the statement that contradicts the basic property of the material. A dielectric is an insulator, so any option claiming it improves conduction is wrong.