An alternating voltage source is connected to a resistor R, and a capacitor C, then which of the following statements about phase angle between voltage V and current I is correct?
Correct answer: C. In the resistor, I and V are in phase - In the capacitor, I leads V by 90 degrees
- A. In the resistor, I leads V by 90 degrees - In the capacitor, I leads V by 90 degrees
- B. In the resistor, I lags V by 90 degrees - In the capacitor, I leads V by 90 degrees
- C. In the resistor, I and V are in phase - In the capacitor, I leads V by 90 degrees
- D. In the resistor, I and V are in phase - In the capacitor, I lags V by 90 degrees
- E. In the resistor, I lags V by 90 degrees - In the capacitor, I lags V by 90 degrees
Explanation
In a resistor, the current and voltage are in phase because the current flows in the same direction as the voltage. However, in a capacitor, the current leads the voltage by 90 degrees because the capacitor initially resists the flow of current and stores energy in its electric field. As the voltage across the capacitor increases, the current begins to flow, and it reaches its maximum value when the voltage is at its minimum value. Therefore, the current leads the voltage by 90 degrees in a capacitor.
Last updated
About AC Through Resistor, Capacitor and Inductor
Alternating current through a resistor, capacitor and inductor involves phase relationships between voltage and current, reactance, impedance and energy transfer. A resistor keeps voltage and current in phase, while a capacitor and inductor produce opposite phase shifts, a distinction used in circuit diagrams and numerical calculations.
Practise Alternating Current
592 free Alternating Current MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A 10Ω electric heater is connected to a 220V 50Hz mains supply. What is the peak value of the potential difference across the heater element ?
A 220 V main supply is connected to a resistance of 100 k ohms. The effective current is
A 50-m coil carries a current of 2 amperes. The energy stored in a magnetic field is:
A.C. and D.C. have the same __________?
A.C and D.C have the same: