Capacitance Flashcards
(30 cards)
What is the definition of capacitance?
Capacitance is the ability of a system to store electric charge per unit voltage.
What is the unit of capacitance?
The unit of capacitance is the farad (F).
True or False: Capacitance is dependent on the voltage applied across the capacitor.
False.
Fill in the blank: Capacitance (C) is defined as C = ____/V, where Q is charge and V is voltage.
Q
What factors determine the capacitance of a parallel plate capacitor?
The area of the plates and the distance between them, along with the dielectric material.
Multiple Choice: Which of the following materials can increase capacitance when placed between capacitor plates? A) Air B) Plastic C) Vacuum D) Water
B) Plastic
What is the formula for the capacitance of a parallel plate capacitor?
C = ε₀(A/d), where ε₀ is the permittivity of free space, A is the area of the plates, and d is the distance between them.
True or False: A capacitor can store both positive and negative charges.
True.
What is the relationship between charge (Q), capacitance (C), and voltage (V)?
Q = C * V.
Fill in the blank: The energy (U) stored in a capacitor is given by the formula U = ____.
1/2 C V^2
Multiple Choice: What happens to the capacitance if the distance between the plates is doubled? A) Doubles B) Halves C) Stays the same D) Quadruples
B) Halves
What is the effect of adding a dielectric material to a capacitor?
It increases the capacitance by reducing the electric field between the plates.
True or False: The equivalent capacitance of capacitors in series is greater than the capacitance of any individual capacitor.
False.
What is the equivalent capacitance (C_eq) for two capacitors in series (C1 and C2)?
C_eq = 1 / (1/C1 + 1/C2).
Fill in the blank: The equivalent capacitance of capacitors in parallel is the ____ of their capacitances.
sum
Multiple Choice: Which of the following is a common application of capacitors? A) Energy storage B) Signal filtering C) Timing circuits D) All of the above
D) All of the above
What does the term ‘dielectric strength’ refer to?
The maximum electric field that a dielectric material can withstand without breakdown.
True or False: Capacitors can only be used in DC circuits.
False.
What is the impact of temperature on capacitance?
Capacitance can vary with temperature, depending on the dielectric material.
Fill in the blank: The term ‘leakage current’ refers to ____ that flows through a capacitor even when it is not connected to a circuit.
the small amount of current
Multiple Choice: What type of capacitor is typically used for high-frequency applications? A) Electrolytic B) Ceramic C) Film D) Tantalum
B) Ceramic
What is the role of a capacitor in an AC circuit?
It stores and releases energy, affecting the phase relationship between voltage and current.
True or False: The capacitance of a capacitor can change over time due to wear and environmental factors.
True.
What is the primary function of a capacitor in a power supply circuit?
To smooth out fluctuations in voltage.
