Capacitive Reactance Question & Answers January 14, 2023 By Wat Electrical This article lists 40 Capacitive Reactance MCQs for engineering students. All the Capacitive Reactance Questions & Answers given below include a hint and a link wherever possible to the relevant topic. This is helpful for users who are preparing for their exams, interviews, or professionals who would like to brush up on the fundamentals of Capacitive Reactance. In electricity, reactance is the term that defines the opposition caused by the circuit to the current flow whether it is alternating or varying. The opposition to the currents that are steadily flowing in the conductors is referred to as 'Electrical Resistance', but not reactance. Resistance and reactance can be present if the alternating currents are carried by the conductors. For direct currents, if there is a change in approach the reactance happens for short durations. For Example, a switch opened or closed. Reactance in the circuit is categorized into two different types. They are Inductive and capacitive. Inductive reactance deals with the concept of magnetic fields. Capacitive reactance deals with the electric field changing among the plates of conduction separated via a medium called dielectric. Such conductors oppose the change in the potential difference across the plates of the capacitor. Hence, the circuit began to retard the flow of current. Alternating voltages in the circuit lags behind alternating currents it is just the opposite scenario caused in inductors. The opposite measure is capacitive reactance and is inverse in proportion to the frequency of signals and the capacitance. It has the units same as resistance i.e., Ohms. Capacitors are devices used for charge storage temporarily. 1). What measures opposition to AC by capacitor? Capacitance Inductance Capacitive Reactance Resistance Hint 2). What are the units of Capacitive Reactance? Farad Ohms Weber Tesla Hint 3). ________ varies inversely with the frequencies applied? Capacitance Inductance Capacitive Reactance Resistance Hint 4). Increase in frequency ________ the capacitive reactance? Increase Decrease Remains the Same Constant Hint 5). XC is the symbol for __________? Capacitance Inductance Capacitive Reactance Resistance Hint 6). What is the formula to calculate Capacitive Reactance? 1/2πf C 2πf C 1/f C 1/2πf Hint 7). If the frequency is Greater then reactance will be_________ ? Higher Lower Incremented Remains Same Hint 8). How capacitance is related to Capacitive reactance? Directly Proportional Inversely Proportional Does Not Affect None Hint 9). How the current flow is related to the change in the supply voltage of a capacitor? Directly Proportional Inversely Proportional Does Not Affect None Hint 10). AC circuits have _____________? Capacitance Inductance Capacitive Reactance Resistance Hint 11). Capacitive reactance is zero for ____________ frequency? Finite Infinite Zero Limited Hint 12). Voltage opposition across capacitors generates ____________? Capacitance Inductance Capacitive Reactance Resistance Hint 13). DC can be blocked due to _________? Capacitance Inductance Capacitive Reactance Resistance Hint 14). Voltage lags behind currents in ___________? Capacitive Reactance Inductive Reactance Resistance Transconductance Hint 15). What does a conductor consist of along with resistance? Capacitance Inductance Reactance Transconductance Hint Capacitive Reactance MCQs for Interviews 16). What is present when switches are opened or closed? Capacitance Inductance Reactance Transconductance Hint 17). What are the various reactance's? Capacitive Reactance Inductive Reactance Resistance a & b Hint 18). AC circuit containing a resistor followed by a capacitor its overall impedance is calculated by? Z2 = R2+ Xc2 Z2 = R2- Xc2 Z2 = R2 Z2 = Xc2 Hint 19). Ratio of RMS voltages to current is __________? Capacitance Inductance Capacitive Reactance Resistance Hint 20). Current guides voltage because of _________? Capacitance Inductance Capacitive Reactance Resistance Hint 21). Why does DC have infinite capacitive reactance's? Frequency Being Zero High Frequency High Currents High Voltages Hint 22). Capacitive reactance is ________? Positive Negative Zero Infinite Hint 23). What happens to reactance if plate sizes increased in the capacitor? Capacitive Reactance Increased Negatively Capacitive Reactance Decreased Negatively Capacitive Reactance is Constant None Hint 24). What remains similar for DC or AC? Capacitive Reactance Inductive Reactance Resistance Transconductance Hint 25). What happens if Capacitive reactance in a circuit is less than Inductive reactance? Voltage Leads Current Current Leads Voltage Voltage Lags Current b & c Hint 26). At what condition current leads the voltage? Capacitive Reactance Inductive Reactance Resistance Transconductance Hint 27). What affects capacitive reactance? Plates Area Dielectric Thickness Dielectric Material All Mentioned Above Hint 28). Energy released in electric field form by reactance is known as ________? Capacitive Reactance Inductive Reactance Resistance Transconductance Hint 29). What improves the power factor in the circuit? Decrease in Capacitive Reactance Increase in Capacitance Increase in Current All Mentioned Above Hint 30). At lower frequencies the circuit if series is __________? Capacitive Inductive Resistive a & b Hint Capacitive Reactance MCQs for Students 31). Resonance occurs if XL is _________to XC? Equal To Greater Than Less Than Greater Than and Equal To Hint 32). If we double the frequency how does the capacitive reactance change? Increase Decrease Remains the Same Constant Hint 33). How the total reactance is calculated if inductive and capacitive reactances are given? X = XL- XC X = XL+ XC X = XL X = - XC Hint 34). How much the voltage lags current in the capacitor ideally? 0 Degrees 90 Degrees 180 Degrees 360 Degrees Hint 35). In an AC circuit, if the resistance offered is 5 ohms, Xc is 12 Ohms. Calculate Impedance. 15 Ohms 14 Ohms 13 Ohms 12 Ohms Hint 36). Calculate resistance if the AC circuit has an impedance of 24 ohms and its Xc of 22 Ohms. 5 Ohms 10 Ohms 15 Ohms 20 Ohms Hint 37). For Ac supply of 100Volts, 50Hertz connected with 20 micro farad capacitances. Find current. 0.5 A 0.6 A 1.6 A 2.6 A Hint 38). Capacitive reactance is not present in ___________? AC Circuits DC Circuits a & b Can’t Say Hint 39). A capacitor with reactance is -6600Ohms at a frequency of 800 K Hz. Calculate capacitance. -3.6 F -3.01 µF -3.01 pF 3.01 pF Hint 40). A capacitor with a capacitance of 166 Pico farads at a frequency of 400 K Hz. Calculate Xc. -2 Ohms -2.4 K Ohms 2.4 Ohms -2.4 Ohms Hint Time's up