The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t² − 50t + 250. The induced emf at t = 3s is

When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is

In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is

The self-inductance of a straight conductor is ________________.

If a secondary coil has 40 turns, and a primary coil with 20 turns is charged with 50V of potential difference, then potential difference in secondary would be ________________.

List out the advantages of stationary armature-rotating field system of AC generator.

Define average value of an alternating current.

When does the phenomenon of resonance is possibble in the circuit?

What is phasor?

Does the current in an a.c circuit lag lead or remain in phase with the applied voltage. When
(i)  γ =  γ_r
(ii)  γ <  γ_r
(iii)  γ >  γ_r
Where  γ_r is the resonant frequency?

A cylindrical bar magnet is kept along the axis of a circular solenoid. If the magnet is rotated about its axis, find out whether an electric current is induced in the coil.

A closed coil of 40 turns and of area 200 cm², is rotated in a magnetic field of flux density 2 Wb m^–2. It rotates from a position where its plane makes an angle of 30^o with the field to a position perpendicular to the field in a time 0.2 s. Find the magnitude of the emf induced in the coil due to its rotation.

Distinguish between average & rms value of an AC.

Give and explain the mechanical analogy of LC oscillations by qualitative treatment.

What is impedance? When does LCR circuit have minimum impedance?

Write down the equation for a sinusoidal voltage of 50 Hz and its peak value is 20 V. Draw the corresponding voltage versus time graph.

A capacitor of capacitance \(\frac { { 10 }^{ -4 } }{ \pi } F\), an inductor of inductance \(\frac { 2 }{ \pi } H\) and a resistor of resistance 100 Ω are connected to form a series RLC circuit. When an AC supply of 220 V, 50 Hz is applied to the circuit, determine
(i) the impedance of the circuit
(ii) the peak value of current flowing in the circuit
(iii) the power factor of the circuit and
(iv) the power factor of the circuit at resonance.

The instantaneous voltage from an ac source is given by V = 300 sin 314t. What is the rms voltage of the sauce? Find its peak voltage and frequency of the sauce?

Calculate the instantaneous voltage for AC supply of 220 V and 50 Hz.