Electronic Circuits Fundamentals and Applications 3rd. Edition by Tooley BA; Advanced Technological and Higher National Certificates Kingston University, Mike | 9780750669238 | 0750669233

Electronic Circuits Fundamentals and Applications

5 SOLVED PROBLEMS

169 SOLVED PROBLEMS

Question: 5.68

An inductor of 100 mH is required. If a closed magnetic core of length 20 cm, cross-sectional area 15 cm² and relative permeability 500 is available, determine the number of turns required. ...

Verified Answer:

L=\frac{\mu_0 \mu_{ r } n^2 A}{1}

a...

Question: 5.71

A waveform has a frequency of 400 Hz. What is the periodic time of the waveform? ...

Verified Answer:

t=\frac{1}{f}=\frac{1}{400 \ Hz } =[/latex...

Question: 5.57

A 150 μF capacitor is charged to a potential of 150 V. The capacitor is then removed from the charging source and connected to a 2 MΩ resistor. Determine the capacitor voltage 1 minute later. ...

Verified Answer:

We will solve this problem using the tabular metho...

Question: 5.40

A current of 1.5 A is drawn from a 3 V battery. What power is supplied? ...

Verified Answer:

Here we must use P = I ×V where I = 1.5 A and V = ...

Question: 3.11

A 10 μF capacitor is charged to a potential of 20 V and then discharged through a 47 kΩ resistor. Determine the time taken for the capacitor voltage to fall below 10 V. ...

Verified Answer:

The formula for exponential decay of voltage in th...

Question: 4.16

A transformer has 1,200 primary turns and is designed to operate with a 200 V a.c. supply. If the transformer is required to produce an output of 10 V, determine the number of secondary turns required. Assuming that the transformer is loss-free, determine the input (primary) current for a load ...

Verified Answer:

Rearranging

\frac{V_P}{V_S} = \frac{N_P}{...

Question: 4.15

A transformer has 2,000 primary turns and 120 secondary turns. If the primary is connected to a 220 V r.m.s. a.c. mains supply, determine the secondary voltage. ...

Verified Answer:

Rearranging

\frac{V_P}{V_S} = \frac{N_P}{...

Question: 4.14

A series L–C–R circuit comprises an inductor of 20 mH, a capacitor of 10 nF, and a resistor of 100 Ω. If the circuit is supplied with a sinusoidal signal of 1.5 V at a frequency of 2 kHz, determine the current supplied and the voltage developed across the resistor. ...

Verified Answer:

First we need to determine the values of inductive...

Question: 4.11

A 2 μF capacitor is connected in series with a 100 F resistor across a 115 V 400 Hz a.c. supply. Determine the impedance of the circuit and the current taken from the supply. ...

Verified Answer:

First we must find the reactance of the capacitor,...

Question: 4.10

A 100 mH inductor of negligible resistance is to form part of a filter which carries a current of 20 mA at 400 Hz. What voltage drop will be developed across the inductor? ...

Verified Answer:

The reactance of the inductor will be given by: X[...

Question: 4.9

Determine the reactance of a 10 mH inductor at (a) 100 Hz and (b) at 10 kHz. ...

Verified Answer:

(a) at 100 Hz X

_L

= 20 × 100 × 10 ×...

Question: 4.8

A 100 nF capacitor is to form part of a filter connected across a 240 V 50 Hz mains supply. What current will flow in the capacitor? ...

Verified Answer:

First we must find the reactance of the capacitor:...

Question: 4.6

A sinusoidal voltage 10 V pk-pk is applied to a resistor of 1 kF What value of r.m.s. current will flow in the resistor? ...

Verified Answer:

This problem must be solved in two stages. First w...

Question: 4.5

An alternating current has a peak-peak value of 50 mA. What is its r.m.s. value? ...

Verified Answer:

The corresponding multiplying factor (found from T...

Question: 4.1

A sine wave voltage has a maximum value of 20 V and a frequency of 50 Hz. Determine the instantaneous voltage present (a) 2.5 ms and (b) 15 ms from the start of the cycle. ...

Verified Answer:

We can find the voltage at any instant of time usi...