# Electrical Measurements Questions and Answers – Inductive Transducer

This set of Electrical Measurements & Measuring Instruments Multiple Choice Questions & Answers (MCQs) focuses on “Inductive Transducer”.

1. Mutual inductance between two coils is given as _________
a) M = k$$\sqrt{L_1 L_2}$$
b) M = k$$\sqrt{L_1}$$
c) M = k$$\sqrt{L_2}$$
d) M = $$\sqrt{L_1 L_2}$$

Explanation: The mutual inductance between two coils is given by the relation
M = k$$\sqrt{L_1 L_2}$$
where, k is the coefficient of coupling
M is the mutual inductance between the coils.

2. Mutual inductance depends on _________
a) self-inductance
b) self-inductance and coefficient of coupling
c) coefficient of coupling
d) permittivity of air

Explanation: The mutual inductance of a pair of coils depends on the self-inductance of the individual coils and on the coefficient of coupling.

3. Self-inductance of an inductor is given by ________
a) L = NS
b) L = 1S
c) L = N2S
d) L = N2

Explanation: The self-inductance of an inductor is obtained by making use of the relation
L = N2S
where, N is the number of coil
S is the reluctance of the coil (A/Wb).

4. Reluctance of a coil is given by which of the following relation?
a) S = 1A
b) S = 1μ
c) S = aμA
d) S = 1μA

Explanation: The reluctance of an inductance coil is given by the relation
S = 1μA
where, l is the length of the magnetic circuit (m)
a is the area of the magnetic circuit which encloses the flux (m2)
µ is the permeability of the core (H/m).

5. Self-inductance depends on ________
a) permeability
b) permittivity
c) plank’s constant
d) rydberg constant

Explanation: The self-inductance of an inductor is obtained by making use of the relation
L = N2S
where, N is the number of coil
S is the reluctance of the coil (A/Wb)
As reluctance depends on the permeability, the self-inductance of a coil depends on the permeability.

6. What is the relation between the self-inductance and the reluctance of a coil?
a) directly proportional
b) inversely proportional
c) no relation
d) constant

Explanation: The self-inductance of an inductor is obtained by making use of the relation
L = N2S
where, N is the number of coil
S is the reluctance of the coil (A/Wb)
We observe from the above equation that the self-inductance of a coil is inversely proportional to its reluctance.

7. Based on self-inductance of a coil, how many types of inductive transducers are available?
a) 5
b) 10
c) 4
d) 20

Explanation: Based on the self-inductance of an inductive coil, there are four types of inductive transducers available. They are as follows:
i) Variable permeability inductive transducer
ii) Variable reluctance inductive transducer
iii) Eddy current inductive transducer
iv) Linear variable differential transducer.

8. In an eddy current transducer output depends on the variation in the eddy current.
a) True
b) False

Explanation: An eddy current transducer is a self-generating type of inductive transducer. In an eddy current transducer, output depends on the change in the value of the eddy current at the input.

9. An inductive transducer measures the variation in ________
a) reluctance
b) resistance
c) capacitance
d) self-inductance

Explanation: Inductive transducer measures the variation in the self-inductance and mutual inductance of an inductive coil. Variation in the inductance is measured as a change in the displacement.

10. Inductive transducer is used for the measurement of physical quantities.
a) True
b) False