Basic Electronics and Electrical Engineering: Chapter 6: Measurement and Instrumentation
Measurement and Instrumentation: Important Solved Examples Problems
Anna University Important Solved Examples Problems with Formula, Equation, Explained Solution - Basic Electronics and Electrical Engineering: Chapter 6: Measurement and Instrumentation
Basic Electronics and
Electrical Engineering
Chapter 6:
Measurement and Instrumentation
SOLVED
EXAMPLES
EXAMPLE 1
A moving coil
instrument has the following data, number of turns 100, width of coil 2 cm,
depth of coil 3 cm and flux density in the air gap is 0.1 wb/m2.
Calculate the deflecting torque when carrying a current of 10 mA. Also
calculate the deflection if the control spring constant is 20×10‒7
m/degree.
Solution
Deflecting torque,
Td=NBIA
Td = 100×0.1×10×10‒3×0.02×0.030
Td=6×10‒5
Nm
Controlling Torque,
Tc=KSθ
Tc=20×10‒7
× θ
At steady state
position,
Tc = Td
20×10‒7 × θ =
6×10‒5
θ = (6×10‒5) / (20×10‒7)
θ = 30°
EXAMPLE 2
The PMMC voltmeter has
a coil of 120 turns wound on a rectangular former 35 mm depth and 20 mm wide.
The flux density is 20 wh/m2. Calculate the deflecting torque for a
coil current of 25 mA.
Solution
Deflecting torque, Td
= NBIA
= 120 × 20×10‒3 ×
25×10‒3 × 35×10‒3 × 20 ×10‒3
Td =
21×10‒6 Nm
EXAMPLE 3
A PMMC voltmeter has
150 turns wound on a rectangular former of size 30×20 mm. The flux density is
0.2 wb/m2. Calculate the deflecting torque for a coil current of 20
mA.
Solution
Deflecting torque, Td
= NBIA
= 150 × 0.2 × 20×10‒3
× 30×10‒3 × 20×10‒3
Td
= 36 × 10‒5 Nm
EXAMPLE 4
The change of
inductance for a moving iron ammeter is 3 mH/degree. The control spring
constant is 5×10‒7 N‒m/degree. The maximum deflection of the pointer
is 100°. What is the current corresponding to maximum deflection?
Solution
Deflection, θ = ½ (I2/KS)
× (dL/dθ)
current, I2
= (θ×2×KS) / (dL/dθ)
= (100×2×5×10‒7)
/ (3×10‒6)
I2 = 33.33
I = 5.77
A
EXAMPLE 5
It is required to
convert a 5mA meter with 20Ω internal resistor into 5A ammeter. Calculate the
value of shunt resistance required and multiply factor of the shunt.
Solution
Multiply factor, n = I
/ Ish
= 5 / 0.005 = 1000
Rsh = Rn
/ n‒1 = 20 / (1000‒1)
Rsh
= 0.02 Ω
Basic Electronics and Electrical Engineering: Chapter 6: Measurement and Instrumentation : Tag: Basic Engineering : - Measurement and Instrumentation: Important Solved Examples Problems
Basic Electronics and Electrical Engineering: Chapter 6: Measurement and Instrumentation
Under Subject
Basic Electronics and Electrical Engineering
EE25C04 1st Semester ECE Dept | 2025 Regulation | 2nd Semester 2025 Regulation
Related Subjects
English Essentials I
EN25C01 1st Semester | 2025 Regulation | 1st Semester 2025 Regulation
தமிழர் மரபு - Heritage of Tamils
UC25H01 1st Semester | 2025 Regulation | 1st Semester 2025 Regulation
Applied Calculus
MA25C01 Maths 1 M1 - 1st Semester | 2025 Regulation | 1st Semester 2025 Regulation
Applied Physics I
PH25C01 1st Semester | 2025 Regulation | 1st Semester 2025 Regulation
Applied Chemistry I
CY25C01 1st Semester | 2025 Regulation | 1st Semester 2025 Regulation
Makerspace
ME25C04 1st Semester | 2025 Regulation | 1st Semester 2025 Regulation
Computer Programming C
CS25C01 1st Semester | 2025 Regulation | 1st Semester 2025 Regulation
Computer Programming Python
CS25C02 1st Semester | 2025 Regulation | 1st Semester 2025 Regulation
Fundamentals of Electrical and Electronics Engineering
EE25C03 1st Semester | 2025 Regulation | 1st Semester 2025 Regulation
Introduction to Mechanical Engineering
ME25C03 1st Semester | 2025 Regulation | 1st Semester 2025 Regulation
Introduction to Civil Engineering
CE25C01 1st Semester Civil Department | 2025 Regulation | 1st Semester 2025 Regulation
Essentials of Computing
CS25C03 1st Semester - AID CSE IT Department | 2025 Regulation | 1st Semester 2025 Regulation
Applied Physics I Laboratory
PH25C01 1st Semester practical Laboratory Manual | 2025 Regulation | 1st Semester Laboratory 2025 Regulation
Applied Chemistry I Laboratory
CY25C01 1st Semester practical Laboratory Manual | 2025 Regulation | 1st Semester Laboratory 2025 Regulation
Computer Programming C Laboratory
CS25C01 1st Semester practical Laboratory Manual | 2025 Regulation | 1st Semester Laboratory 2025 Regulation
Computer Programming Python Laboratory
CS25C02 1st Semester practical Laboratory Manual | 2025 Regulation | 1st Semester Laboratory 2025 Regulation
Engineering Drawing
ME25C01 EEE Mech Dept | 2025 Regulation | 2nd Semester 2025 Regulation
Basic Electronics and Electrical Engineering
EE25C04 1st Semester ECE Dept | 2025 Regulation | 2nd Semester 2025 Regulation