Notes, Tests & AI Tutor for Class 5–12 | CBSE · JEE · NEET | 24x7 Access
Student School Teacher Help
Home Schools
Log in Get Started
Home / JEE / Physics / Electromagnetic Induction and Alternating Currents

Electromagnetic Induction and Alternating Currents

JEE Physics · 160 questions. Try each one, then check the answer and solution.

Log in to bookmark questions and track your accuracy chapter by chapter.
Q121. AI-generated practice Single-correct MCQ Easy

The average power consumed in an AC circuit is (φ = phase difference between voltage and current):

Q122. AI-generated practice Single-correct MCQ Easy

The power factor of a circuit containing only an ideal inductor is:

Q123. AI-generated practice Single-correct MCQ Medium
In an AC circuit Vrms = 220 V, Irms = 5 A and the current lags the voltage by 60°. The average power consumed is:
Q124. AI-generated practice Single-correct MCQ Medium
A series RL circuit has R = 30 Ω and XL = 40 Ω. Its power factor is:
Q125. AI-generated practice Single-correct MCQ Medium
The 'wattless' component of an alternating current Irms that lags the voltage by φ is:
Q126. AI-generated practice Single-correct MCQ Hard
A series LCR circuit has R = 40 Ω, XL = 50 Ω and XC = 20 Ω, and is connected to a 200 V (rms) supply. The average power consumed is:
Q127. AI-generated practice Single-correct MCQ Medium

The power factor of a series LCR circuit at resonance is:

Q128. AI-generated practice Single-correct MCQ Medium

Electricity suppliers prefer consumers' loads to have a power factor close to 1 because:

Q129. AI-generated practice Single-correct MCQ Hard

An ideal choke coil is preferred to a resistor for reducing the current in an AC circuit (e.g. in a tube light) because:

Q130. AI-generated practice Single-correct MCQ Easy

The average power consumed by an ideal capacitor connected to an AC supply is:

Q131. AI-generated practice Single-correct MCQ Medium

In an AC circuit the current leads the voltage by 30°. The power factor of the circuit is about:

Q132. AI-generated practice Single-correct MCQ Hard

A device draws 1100 W from a 220 V (rms) supply and has a power factor of 0.5. The rms current it draws is:

Q133. AI-generated practice Single-correct MCQ Medium

The instantaneous power delivered to a resistor connected to an AC supply of frequency f oscillates at a frequency of:

Q134. AI-generated practice Single-correct MCQ Medium

An alternating current of rms value 3 A flows through a 20 Ω resistor for 10 s. The heat produced is:

Q135. AI-generated practice Numerical value Easy
In an AC circuit Vrms = 200 V, Irms = 2 A and the power factor is 0.8. Find the average power in watt.
Q136. AI-generated practice Numerical value Medium
A series RL circuit has R = 8 Ω and XL = 6 Ω. If its power factor is x/10, find x.
Q137. AI-generated practice Numerical value Medium

An alternating current of rms value 10 A lags the voltage by 30°. Find the wattless component of the current in ampere.

Q138. AI-generated practice Numerical value Hard
A series LCR circuit has R = 60 Ω, XL = 100 Ω and XC = 20 Ω, and is connected to a 200 V (rms) supply. Find the average power consumed in watt.
Q139. AI-generated practice Assertion–Reason Medium
Assertion (A): The average power consumed by an ideal inductor connected to an AC source is zero.
Reason (R): The reactance of an inductor increases with the frequency of the supply.
Q140. AI-generated practice Assertion–Reason Hard
Assertion (A): A circuit with a low power factor draws a smaller current from the supply to deliver a given power.
Reason (R): The average power in an AC circuit is VrmsIrms cos φ.