A 100-turn rectangular coil of size 0.20 m × 0.10 m rotates in a magnetic field of 0.003 Wb m–2 with a frequency of 1200 rpm about an axis normal to the field. Find the maximum value of the induced emf


Correct option is

0.75 V

The maximum value of the induced emf is given by 


Where N is the number of turns in the coil, B is the magnetic field, A is the area of the coil and  the angular velocity of the coil. 


    N = 100, B = 0.003 Wb m–2A = 0.20 × 0.10 = 0.02 mand  rpm   





The instantaneous current in a circuit is given by I = 2cos (u4t + Ï•) ampere. The r.m.s value of the current is


A (100w, 200v) bulb is connected to a 160v supply. The power consumption would be


The induced emf in armature will be zero, when armature is rotated at an angle


An a.c. source is of 120 volt , 60Hz the value of the voltage after 1/360  sec from the start will be


Resonance  frequency of a circuit is f if the capacitance is made 4 times the initial value , then the resonance frequency will become


In and A.C. circuit , minimum voltage of 423 Volt. Its effective voltage is


The  average power  dissipation in a pure capacitor in A.C. circuit is


An a.c. generator consisting of a coil of 100 turns and cross-sectional area of 3 m2 is rotating at a constant angular speed of 60 rad s–1 in a uniform magnetic field of 0.04 T. The resistance of the coil is 500 . Calculate maximum current drawn from the generator, and power dissipation in the coil. From where does the power come? 


An a.c. generator consists of a coil of 50 turns and area 2.5 m2 rotating at an angular speed of 60 rad s–1 in a uniform magnetic field of 0.30 T. The resistance of the circuit including that of the coil is 500 . Find the maximum current drawn from the generator.    


In a dynamo, a coil of area 0.2 m2 and having 100 turns rotates in a magnetic field of 0.1 Wb m–2 with an angular velocity of 100 rad s–1. The output terminals are connected through a resistance of . Calculate the torque , as a function of time t, required to keep the coil rotating.