Test: Inductance & AC Generator (January 29) - NEET MCQ

Electric motors have an efficiency of less than 100% because there is ALWAYS energy loss through any mechanism imaginable.

The rate of change of flux linkage is directly proportional to the induced EMF in a coil. Hence, the EMF is maximum when the rate of change of flux linkage is maximum.

E = CV²/2

= 9.2 x (22.5)²/2

= 2328.75 J

n₁=10 turns per cm, =1000 turns per metre
n₂l=100, A=10 c=0.1 m², M=μ₀n₁(n₂l) A
=4πx10^-7×1000×100×0.1H=0.13mh

The total inductance of inductors connected in series is given by the following formula:
L_eq = L₁ + L₂
Substituting the values in the equation, we get the total inductance as
L_eq = L + L = 2L
Hence, the total inductance of two inductors connected in series is 2L.

Fleming's Right hand rule: Hold a current-carrying conductor in your right hand with thumb in the direction of the current, the direction of the field lines will be the direction of your fingers.

Now, e=L(di/dt)
L=e/(di/dt)
1 henry=1 volt/(1 ampere/second)

Mutual inductance is the phenomena where an adjoining wire coil induces the voltage from the magnetic field produced by a wire coil. A transformer is a tool which is made up of two or more coils in close proximity to each other to create a situation of mutual inductance between the coils.The factors determining the value of mutual inductance are —
a. The number of turns of the coils
b. The geometric shape and size of the coils
c. The separation of the coils and
d. The angular orientation between the coils
So clearly it does not depend upon the current flow through both of the cells.

The answer provided in the forum is wrong, the correct answer would be option B and D both.
Solution:
Frequency of a.c, ν=w/2π​, where  w is the speed of rotation
Also, frequency is defined as the number of rotations that a coil rotates in one second.