Jagmohan Singh electrotherapy textbook DPT third year first chapter topics UHS

https://www.scribd.com/document/842938391/Textbook-of-Electr…

ls -la /tmp/workspace/ 2>/dev/null || mkdir -p /tmp/workspace && echo "created"

mkdir -p /tmp/workspace/electrotherapy && python3 << 'PYEOF' from reportlab.lib.pagesizes import A4 from reportlab.lib import colors from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle from reportlab.lib.units import cm, mm from reportlab.platypus import (SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, HRFlowable, KeepTogether, PageBreak) from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY from reportlab.platypus import Flowable OUTPUT = "/tmp/workspace/electrotherapy/Electrotherapy_Ch1_QuickRef.pdf" doc = SimpleDocTemplate( OUTPUT, pagesize=A4, rightMargin=1.8*cm, leftMargin=1.8*cm, topMargin=2*cm, bottomMargin=2*cm, title="Electrotherapy Chapter 1 - Quick Reference", author="Jagmohan Singh DPT" ) # ─── Color palette ─────────────────────────────────────────────── DARK_BLUE = colors.HexColor("#1A3A5C") MED_BLUE = colors.HexColor("#2E6DA4") LIGHT_BLUE = colors.HexColor("#D6E8F7") ACCENT = colors.HexColor("#E8501A") GOLD = colors.HexColor("#F5A623") LIGHT_GREY = colors.HexColor("#F4F6F9") MED_GREY = colors.HexColor("#CCCCCC") GREEN = colors.HexColor("#1E7E34") LIGHT_GREEN = colors.HexColor("#D4EDDA") DARK_TEXT = colors.HexColor("#1A1A2E") # ─── Styles ────────────────────────────────────────────────────── styles = getSampleStyleSheet() def make_style(name, parent='Normal', **kw): s = ParagraphStyle(name, parent=styles[parent], **kw) return s H_COVER = make_style('HCover', fontSize=26, leading=32, textColor=colors.white, alignment=TA_CENTER, fontName='Helvetica-Bold') SUB_COVER = make_style('SubCover', fontSize=13, leading=18, textColor=LIGHT_BLUE, alignment=TA_CENTER, fontName='Helvetica') H1 = make_style('H1', fontSize=13, leading=17, textColor=colors.white, fontName='Helvetica-Bold', spaceAfter=0) H2 = make_style('H2', fontSize=11, leading=14, textColor=DARK_BLUE, fontName='Helvetica-Bold', spaceBefore=8, spaceAfter=4) H3 = make_style('H3', fontSize=10, leading=13, textColor=MED_BLUE, fontName='Helvetica-Bold', spaceBefore=5, spaceAfter=2) BODY = make_style('Body', fontSize=9.5, leading=14, textColor=DARK_TEXT, fontName='Helvetica', spaceAfter=3) BODY_SMALL = make_style('BodySm', fontSize=8.5, leading=12, textColor=DARK_TEXT, fontName='Helvetica') BOLD_BODY = make_style('BoldBody', fontSize=9.5, leading=14, textColor=DARK_TEXT, fontName='Helvetica-Bold') ITALIC = make_style('Italic', fontSize=9, leading=12, textColor=colors.HexColor("#555555"), fontName='Helvetica-Oblique') MCQ_Q = make_style('McqQ', fontSize=9.5, leading=13, textColor=DARK_BLUE, fontName='Helvetica-Bold', spaceBefore=4) MCQ_OPT = make_style('McqOpt', fontSize=9, leading=13, textColor=DARK_TEXT, fontName='Helvetica', leftIndent=14) MCQ_ANS = make_style('McqAns', fontSize=8.5, leading=11, textColor=GREEN, fontName='Helvetica-BoldOblique', leftIndent=14) FORMULA_STYLE = make_style('Formula', fontSize=10, leading=14, textColor=DARK_BLUE, fontName='Helvetica-Bold', alignment=TA_CENTER, spaceBefore=3, spaceAfter=3) # ─── Helper: Section header band ───────────────────────────────── def section_header(text, color=DARK_BLUE): data = [[Paragraph(text, H1)]] t = Table(data, colWidths=[doc.width]) t.setStyle(TableStyle([ ('BACKGROUND', (0,0), (-1,-1), color), ('TOPPADDING', (0,0), (-1,-1), 7), ('BOTTOMPADDING', (0,0), (-1,-1), 7), ('LEFTPADDING', (0,0), (-1,-1), 10), ('RIGHTPADDING', (0,0), (-1,-1), 10), ('ROUNDEDCORNERS', [4]), ])) return t def formula_box(label, formula, note=""): rows = [] if label: rows.append([Paragraph(f"<b>{label}</b>", BOLD_BODY), Paragraph(formula, FORMULA_STYLE)]) if note: rows.append(["", Paragraph(f"<i>{note}</i>", ITALIC)]) t = Table(rows, colWidths=[4.5*cm, doc.width - 4.5*cm]) t.setStyle(TableStyle([ ('BACKGROUND', (0,0), (-1,-1), LIGHT_BLUE), ('BOX', (0,0), (-1,-1), 0.8, MED_BLUE), ('LINEBELOW', (0,0), (-1,-1), 0.3, MED_GREY), ('TOPPADDING', (0,0), (-1,-1), 5), ('BOTTOMPADDING', (0,0), (-1,-1), 5), ('LEFTPADDING', (0,0), (-1,-1), 8), ('VALIGN', (0,0), (-1,-1), 'MIDDLE'), ])) return t def def_table(rows_data, col_ratio=(0.32, 0.68)): col_w = [doc.width * r for r in col_ratio] t = Table(rows_data, colWidths=col_w, repeatRows=1) style = [ ('BACKGROUND', (0,0), (-1,0), MED_BLUE), ('TEXTCOLOR', (0,0), (-1,0), colors.white), ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'), ('FONTSIZE', (0,0), (-1,0), 9.5), ('FONTSIZE', (0,1), (-1,-1), 9), ('FONTNAME', (0,1), (-1,-1), 'Helvetica'), ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.white, LIGHT_GREY]), ('BOX', (0,0), (-1,-1), 0.8, MED_BLUE), ('INNERGRID', (0,0), (-1,-1), 0.3, MED_GREY), ('TOPPADDING', (0,0), (-1,-1), 5), ('BOTTOMPADDING', (0,0), (-1,-1), 5), ('LEFTPADDING', (0,0), (-1,-1), 7), ('VALIGN', (0,0), (-1,-1), 'TOP'), ] t.setStyle(TableStyle(style)) return t story = [] W = doc.width # ═══════════════════════════════════════════════════════════════ # COVER PAGE # ═══════════════════════════════════════════════════════════════ cover_data = [[ Paragraph("ELECTROTHERAPY", H_COVER), Paragraph("Chapter 1: Basics of Electricity, Light &amp; Sound", SUB_COVER), Spacer(1, 0.3*cm), Paragraph("Quick Reference — Definitions · Formulas · MCQs", SUB_COVER), Spacer(1, 0.5*cm), Paragraph("Jagmohan Singh | DPT 3rd Year | UHS", make_style('CovSub2', fontSize=11, textColor=GOLD, alignment=TA_CENTER, fontName='Helvetica-BoldOblique')), ]] cover_tbl = Table(cover_data, colWidths=[W]) cover_tbl.setStyle(TableStyle([ ('BACKGROUND', (0,0), (-1,-1), DARK_BLUE), ('BOX', (0,0), (-1,-1), 2, GOLD), ('TOPPADDING', (0,0), (-1,-1), 35), ('BOTTOMPADDING', (0,0), (-1,-1), 35), ('LEFTPADDING', (0,0), (-1,-1), 20), ('RIGHTPADDING', (0,0), (-1,-1), 20), ])) story.append(cover_tbl) story.append(Spacer(1, 0.8*cm)) # ═══════════════════════════════════════════════════════════════ # PART 1 — KEY DEFINITIONS # ═══════════════════════════════════════════════════════════════ story.append(section_header("PART 1 — KEY DEFINITIONS")) story.append(Spacer(1, 0.3*cm)) defs = [ ["Term", "Definition"], ["Electric Charge (Q)", "Fundamental property of matter. Unit: Coulomb (C). Carried by electrons (negative) and protons (positive)."], ["Electric Current (I)", "Rate of flow of electric charge. I = Q / t. Unit: Ampere (A)."], ["Potential Difference (V)", "Work done per unit charge to move charge between two points. Unit: Volt (V). V = W / Q."], ["Electromotive Force (EMF)", "Force that drives current through a circuit; energy supplied per unit charge by a source. Unit: Volt."], ["Resistance (R)", "Opposition offered by a conductor to the flow of current. Unit: Ohm (Ω). R = V / I."], ["Conductance (G)", "Reciprocal of resistance. G = 1/R. Unit: Siemens (S)."], ["Capacitance (C)", "Ability of a body to store electric charge. C = Q / V. Unit: Farad (F)."], ["Inductance (L)", "Property of a conductor to oppose any change in current through it. Unit: Henry (H)."], ["Power (P)", "Rate of doing electrical work. P = V × I = I²R = V²/R. Unit: Watt (W)."], ["Energy (E)", "Capacity to do work. E = P × t = V × I × t. Unit: Joule (J)."], ["Direct Current (DC)", "Unidirectional, constant flow of charge. Also called Galvanic current in physiotherapy."], ["Alternating Current (AC)", "Current that reverses direction periodically in a sinusoidal pattern."], ["Frequency (f)", "Number of complete cycles per second. Unit: Hertz (Hz). f = 1 / T."], ["Period / Period Time (T)", "Time for one complete cycle. T = 1 / f. Unit: seconds."], ["Amplitude", "Maximum displacement / peak value of a waveform from the baseline."], ["RMS Value", "Root Mean Square value of AC; equivalent DC that produces same heating effect. RMS = 0.707 × Peak."], ["Waveform", "Graphical representation of the variation of current or voltage with time."], ["Monophasic Wave", "Waveform with deflection only on one side of the baseline (all positive or all negative)."], ["Biphasic Wave", "Waveform with deflections on both sides of the baseline (positive and negative phases)."], ["Impedance (Z)", "Total opposition to AC flow. Combination of resistance, capacitance, and inductance. Unit: Ohm."], ["Reactance (X)", "Opposition due to capacitance (Xc) or inductance (XL) in AC circuits."], ["Phase", "The fraction of a cycle that has elapsed, measured from a reference point. Unit: degrees or radians."], ["Electromagnetic Radiation", "Energy propagated as oscillating electric and magnetic fields. Travels at 3×10⁸ m/s in vacuum."], ["Wavelength (λ)", "Distance between two successive crests (or troughs) of a wave. Unit: metre (m). λ = v / f."], ["Infrared Radiation (IR)", "Electromagnetic radiation with wavelength 700 nm – 1 mm. Produces heat; used as thermotherapy."], ["Ultraviolet Radiation (UV)", "Electromagnetic radiation with wavelength 200–400 nm. Bactericidal, stimulates Vit-D, erythema."], ["UV-A", "Long-wave UV: 320–400 nm. Penetrates deeper. Used in PUVA therapy."], ["UV-B", "Mid-wave UV: 290–320 nm. Causes erythema and sunburn. Stimulates Vitamin D synthesis."], ["UV-C", "Short-wave UV: 200–290 nm. Most bactericidal. Does not reach earth naturally."], ["Inverse Square Law", "Intensity of radiation is inversely proportional to the square of the distance from the source. I ∝ 1/d²."], ["Cosine Law (Lambert's)", "Intensity of radiation absorbed is maximum when rays are perpendicular (90°) to the surface. I = Iₒ × cos θ."], ["Ultrasound", "Mechanical longitudinal waves with frequency above 20,000 Hz (>20 kHz). Physiotherapy: 0.5–3 MHz."], ["Piezoelectric Effect", "Production of electrical charge by mechanical pressure on certain crystals (and vice versa). Basis of US transducer."], ["Conductor", "Material with free electrons allowing easy current flow (e.g., copper, silver, saline)."], ["Insulator", "Material that resists current flow (e.g., rubber, glass, dry skin)."], ["Semiconductor", "Material with conductivity between conductor and insulator (e.g., silicon, germanium)."], ["Macroshock", "Electric current entering through body surface, reaching heart externally."], ["Microshock", "Very small current (<1 mA) applied directly to heart via catheter — can cause VF."], ["Let-go Current", "~10–20 mA AC. Current causing sustained tetanic grip; person cannot release the source voluntarily."], ["Threshold of Perception", "Minimum current perceptible. ~1 mA for AC, ~5 mA for DC."], ["Iontophoresis", "Use of DC to drive ionized drugs through skin. Requires unidirectional (galvanic) current."], ["Galvanic Skin Reaction", "Physiological response of skin to galvanic (DC) current: hyperemia, ion migration, chemical changes."], ] story.append(def_table(defs)) story.append(Spacer(1, 0.5*cm)) # ═══════════════════════════════════════════════════════════════ # PART 2 — FORMULAS & UNITS # ═══════════════════════════════════════════════════════════════ story.append(section_header("PART 2 — FORMULAS & UNITS AT A GLANCE", color=MED_BLUE)) story.append(Spacer(1, 0.3*cm)) story.append(Paragraph("A. Fundamental Electrical Formulas", H2)) elec_formulas = [ ["Quantity", "Formula", "Unit"], ["Current", "I = Q / t", "Ampere (A)"], ["Voltage", "V = W / Q or V = I × R", "Volt (V)"], ["Resistance", "R = V / I", "Ohm (Ω)"], ["Conductance", "G = 1 / R", "Siemens (S)"], ["Power", "P = V × I = I²R = V²/R", "Watt (W)"], ["Energy", "E = P × t = V × I × t", "Joule (J)"], ["Capacitance", "C = Q / V", "Farad (F)"], ["Impedance (AC)", "Z = √(R² + X²)", "Ohm (Ω)"], ["Frequency", "f = 1 / T", "Hertz (Hz)"], ["RMS Current", "I_rms = 0.707 × I_peak", "Ampere (A)"], ["Average Current", "I_avg = 0.637 × I_peak", "Ampere (A)"], ["Form Factor", "Form Factor = I_rms / I_avg = 1.11", "—"], ] ft = Table(elec_formulas, colWidths=[W*0.30, W*0.42, W*0.28], repeatRows=1) ft.setStyle(TableStyle([ ('BACKGROUND', (0,0), (-1,0), DARK_BLUE), ('TEXTCOLOR', (0,0), (-1,0), colors.white), ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'), ('FONTSIZE', (0,0), (-1,-1), 9), ('FONTNAME', (0,1), (-1,-1), 'Helvetica'), ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.white, LIGHT_BLUE]), ('BOX', (0,0), (-1,-1), 0.8, DARK_BLUE), ('INNERGRID', (0,0), (-1,-1), 0.3, MED_GREY), ('TOPPADDING', (0,0), (-1,-1), 5), ('BOTTOMPADDING', (0,0), (-1,-1), 5), ('LEFTPADDING', (0,0), (-1,-1), 7), ('ALIGN', (2,0), (2,-1), 'CENTER'), ('VALIGN', (0,0), (-1,-1), 'MIDDLE'), ])) story.append(ft) story.append(Spacer(1, 0.4*cm)) story.append(Paragraph("B. Wave & Radiation Formulas", H2)) wave_formulas = [ ["Quantity", "Formula", "Notes"], ["Wave Equation", "v = f × λ", "v = 3×10⁸ m/s (EM in vacuum)"], ["Period", "T = 1 / f", "T in seconds"], ["Inverse Square Law", "I ∝ 1 / d²", "I₁/I₂ = d₂²/d₁²"], ["Cosine (Lambert's) Law", "I = I₀ × cos θ", "Max at θ = 0° (perpendicular)"], ["UV Erythema Dose (MED)", "Minimum erythemal dose", "Varies with Fitzpatrick skin type"], ["Ultrasound Intensity", "I = P / A", "Unit: W/cm²"], ["Snell's Law (Refraction)", "n₁ sin θ₁ = n₂ sin θ₂", "For oblique incidence"], ] ft2 = Table(wave_formulas, colWidths=[W*0.28, W*0.32, W*0.40], repeatRows=1) ft2.setStyle(TableStyle([ ('BACKGROUND', (0,0), (-1,0), MED_BLUE), ('TEXTCOLOR', (0,0), (-1,0), colors.white), ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'), ('FONTSIZE', (0,0), (-1,-1), 9), ('FONTNAME', (0,1), (-1,-1), 'Helvetica'), ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.white, LIGHT_GREY]), ('BOX', (0,0), (-1,-1), 0.8, MED_BLUE), ('INNERGRID', (0,0), (-1,-1), 0.3, MED_GREY), ('TOPPADDING', (0,0), (-1,-1), 5), ('BOTTOMPADDING', (0,0), (-1,-1), 5), ('LEFTPADDING', (0,0), (-1,-1), 7), ('VALIGN', (0,0), (-1,-1), 'MIDDLE'), ])) story.append(ft2) story.append(Spacer(1, 0.4*cm)) story.append(Paragraph("C. Electromagnetic Spectrum Summary", H2)) em_data = [ ["Type", "Wavelength", "Frequency", "Physiotherapy Use"], ["Radio Waves", ">1 mm", "<300 GHz", "SWD, MWD"], ["Microwave", "1 mm – 1 m", "300 MHz–300 GHz", "Microwave Diathermy"], ["Infrared (Far)", "3 µm – 1 mm", "300 GHz – 100 THz", "Heat lamps (non-lum.)"], ["Infrared (Near)", "700 nm – 3 µm", "100–430 THz", "Heat lamps (lum.), Laser"], ["Visible Light", "400–700 nm", "430–750 THz", "Phototherapy, LLLT"], ["UV-A", "320–400 nm", "750–940 THz", "PUVA therapy"], ["UV-B", "290–320 nm", "940 THz–1 PHz", "Vit D, psoriasis"], ["UV-C", "200–290 nm", "1–1.5 PHz", "Bactericidal (wounds)"], ["X-rays", "<10 nm", ">30 PHz", "Diagnostic/Radiotherapy"], ] em = Table(em_data, colWidths=[W*0.22, W*0.20, W*0.23, W*0.35], repeatRows=1) em.setStyle(TableStyle([ ('BACKGROUND', (0,0), (-1,0), DARK_BLUE), ('TEXTCOLOR', (0,0), (-1,0), colors.white), ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'), ('FONTSIZE', (0,0), (-1,-1), 8.5), ('FONTNAME', (0,1), (-1,-1), 'Helvetica'), ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.white, LIGHT_GREY]), ('BOX', (0,0), (-1,-1), 0.8, DARK_BLUE), ('INNERGRID', (0,0), (-1,-1), 0.3, MED_GREY), ('TOPPADDING', (0,0), (-1,-1), 4), ('BOTTOMPADDING', (0,0), (-1,-1), 4), ('LEFTPADDING', (0,0), (-1,-1), 6), ('VALIGN', (0,0), (-1,-1), 'MIDDLE'), ])) story.append(em) story.append(Spacer(1, 0.4*cm)) story.append(Paragraph("D. Electrical Safety Thresholds", H2)) safety = [ ["Current Level", "Effect"], ["1 mA (AC)", "Threshold of perception"], ["5 mA (DC)", "Threshold of perception"], ["10–20 mA (AC)", "Let-go current — tetanic contraction, cannot release"], ["50–100 mA (AC)", "Ventricular fibrillation (VF) if transthoracic"], ["1–10 µA (direct to heart)", "Microshock — can cause VF"], ["Leakage current (medical devices)", "Must not exceed 500 µA"], ] sf = Table(safety, colWidths=[W*0.40, W*0.60], repeatRows=1) sf.setStyle(TableStyle([ ('BACKGROUND', (0,0), (-1,0), colors.HexColor("#8B0000")), ('TEXTCOLOR', (0,0), (-1,0), colors.white), ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'), ('FONTSIZE', (0,0), (-1,-1), 9), ('FONTNAME', (0,1), (-1,-1), 'Helvetica'), ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.white, colors.HexColor("#FFEEEE")]), ('BOX', (0,0), (-1,-1), 0.8, colors.HexColor("#8B0000")), ('INNERGRID', (0,0), (-1,-1), 0.3, MED_GREY), ('TOPPADDING', (0,0), (-1,-1), 5), ('BOTTOMPADDING', (0,0), (-1,-1), 5), ('LEFTPADDING', (0,0), (-1,-1), 7), ('VALIGN', (0,0), (-1,-1), 'MIDDLE'), ])) story.append(sf) story.append(PageBreak()) # ═══════════════════════════════════════════════════════════════ # PART 3 — MCQs # ═══════════════════════════════════════════════════════════════ story.append(section_header("PART 3 — MULTIPLE CHOICE QUESTIONS (35 MCQs)", color=colors.HexColor("#1E4D2B"))) story.append(Spacer(1, 0.3*cm)) story.append(Paragraph("Answers are highlighted in green. A brief explanation follows each question.", ITALIC)) story.append(Spacer(1, 0.3*cm)) mcqs = [ { "sec": "SECTION A — ELECTRICITY FUNDAMENTALS", "qs": [ { "q": "Q1. The SI unit of electric charge is:", "opts": ["A) Ampere", "B) Volt", "C) Coulomb", "D) Ohm"], "ans": "C) Coulomb", "exp": "One Coulomb = charge carried by 6.28 × 10¹⁸ electrons. Named after Charles-Augustin de Coulomb." }, { "q": "Q2. Electric current is defined as:", "opts": ["A) Force per unit charge", "B) Work done per unit charge", "C) Rate of flow of electric charge", "D) Potential difference per unit resistance"], "ans": "C) Rate of flow of electric charge", "exp": "I = Q / t. Unit is Ampere (A)." }, { "q": "Q3. Ohm's Law states that:", "opts": ["A) V = I² × R", "B) V = I × R", "C) I = V² / R", "D) R = V² × I"], "ans": "B) V = I × R", "exp": "Voltage = Current × Resistance. Ohm's Law is valid for linear, resistive conductors at constant temperature." }, { "q": "Q4. The unit of electrical resistance is:", "opts": ["A) Siemens", "B) Farad", "C) Ohm (Ω)", "D) Henry"], "ans": "C) Ohm (Ω)", "exp": "1 Ohm = resistance when 1 Ampere flows under 1 Volt potential difference." }, { "q": "Q5. The unit of electrical conductance is:", "opts": ["A) Ohm", "B) Siemens (S)", "C) Ampere", "D) Watt"], "ans": "B) Siemens (S)", "exp": "Conductance G = 1/R. Also called mho (℧)." }, { "q": "Q6. Electrical power is measured in:", "opts": ["A) Joule", "B) Volt", "C) Watt", "D) Coulomb"], "ans": "C) Watt", "exp": "P = V × I. 1 Watt = 1 Joule/second." }, { "q": "Q7. The property of a conductor that opposes any change in current is called:", "opts": ["A) Resistance", "B) Capacitance", "C) Inductance", "D) Conductance"], "ans": "C) Inductance", "exp": "Inductance (L) is measured in Henry (H). It produces a back-EMF opposing changes in current." }, { "q": "Q8. Capacitance is defined as the ability to:", "opts": ["A) Resist flow of current", "B) Store electric charge", "C) Generate electromotive force", "D) Convert AC to DC"], "ans": "B) Store electric charge", "exp": "C = Q/V. Unit: Farad (F). Capacitors block DC but pass AC." }, { "q": "Q9. Electrical energy is measured in:", "opts": ["A) Watts", "B) Volts", "C) Joules", "D) Amperes"], "ans": "C) Joules", "exp": "E = P × t = V × I × t. Also expressed as Watt-seconds or kWh for large quantities." }, { "q": "Q10. In which tissue is electrical resistance HIGHEST?", "opts": ["A) Blood", "B) Muscle", "C) Nerve", "D) Bone"], "ans": "D) Bone", "exp": "Bone has very high resistance due to low water content. Blood and nerve have the lowest resistance." }, ] }, { "sec": "SECTION B — TYPES OF CURRENT & WAVEFORMS", "qs": [ { "q": "Q11. Direct current (DC) used in physiotherapy is also called:", "opts": ["A) Faradic current", "B) Galvanic current", "C) Sinusoidal current", "D) Interferential current"], "ans": "B) Galvanic current", "exp": "Galvanic current = continuous unidirectional DC. Named after Luigi Galvani." }, { "q": "Q12. In alternating current, the direction of current flow:", "opts": ["A) Is always constant", "B) Changes once only", "C) Reverses periodically", "D) Flows in one direction"], "ans": "C) Reverses periodically", "exp": "AC reverses direction with each half-cycle. Mains AC in Pakistan = 50 Hz." }, { "q": "Q13. Frequency is defined as:", "opts": ["A) Time for one cycle", "B) Maximum current in one cycle", "C) Number of complete cycles per second", "D) Rate of change of voltage"], "ans": "C) Number of complete cycles per second", "exp": "f = 1/T. Unit: Hertz (Hz). 1 Hz = 1 cycle/second." }, { "q": "Q14. The RMS value of sinusoidal AC in relation to peak value is:", "opts": ["A) RMS = Peak × 2", "B) RMS = Peak × 0.5", "C) RMS = Peak × 0.707", "D) RMS = Peak × 1.414"], "ans": "C) RMS = Peak × 0.707", "exp": "RMS = Peak / √2 = 0.707 × Peak. RMS produces the same heating effect as equivalent DC." }, { "q": "Q15. A biphasic waveform is one that:", "opts": ["A) Has only a positive phase", "B) Has only a negative phase", "C) Has both positive and negative phases", "D) Has constant amplitude"], "ans": "C) Has both positive and negative phases", "exp": "Biphasic = deflections on both sides of baseline. Monophasic = only one side." }, { "q": "Q16. Which current is used in iontophoresis?", "opts": ["A) Alternating current", "B) Faradic current", "C) Direct (galvanic) current", "D) Interferential current"], "ans": "C) Direct (galvanic) current", "exp": "Iontophoresis requires unidirectional DC to drive ions through skin. AC would cause ions to oscillate without net movement." }, { "q": "Q17. The time taken for one complete cycle of AC is called:", "opts": ["A) Frequency", "B) Amplitude", "C) Period (T)", "D) Phase"], "ans": "C) Period (T)", "exp": "T = 1/f. For 50 Hz mains: T = 0.02 seconds = 20 ms." }, ] }, { "sec": "SECTION C — ELECTROMAGNETIC SPECTRUM & RADIATION", "qs": [ { "q": "Q18. The velocity of electromagnetic waves in a vacuum is:", "opts": ["A) 3 × 10⁶ m/s", "B) 3 × 10⁴ m/s", "C) 3 × 10⁸ m/s", "D) 3 × 10¹⁰ m/s"], "ans": "C) 3 × 10⁸ m/s", "exp": "Speed of light = 3 × 10⁸ m/s (approximately 300,000 km/s). All EM waves travel at this speed in vacuum." }, { "q": "Q19. The relationship between velocity (v), frequency (f) and wavelength (λ) is:", "opts": ["A) v = f / λ", "B) v = λ / f", "C) v = f × λ", "D) f = v × λ"], "ans": "C) v = f × λ", "exp": "This is the fundamental wave equation. Rearranged: λ = v/f or f = v/λ." }, { "q": "Q20. Infrared radiation has a wavelength in the range of:", "opts": ["A) 200–400 nm", "B) 400–700 nm", "C) 700 nm – 1 mm", "D) 1 mm – 1 m"], "ans": "C) 700 nm – 1 mm", "exp": "IR is divided into near-IR (700 nm – 3 µm) and far-IR (3 µm – 1 mm). Both produce thermal effects." }, { "q": "Q21. UV-C (far UV) has a wavelength range of:", "opts": ["A) 320–400 nm", "B) 290–320 nm", "C) 200–290 nm", "D) 100–200 nm"], "ans": "C) 200–290 nm", "exp": "UV-A: 320–400 nm (long). UV-B: 290–320 nm (mid). UV-C: 200–290 nm (short/germicidal). Mnemonic: ABC = Ascending wavelength." }, { "q": "Q22. The Inverse Square Law states that intensity of radiation is:", "opts": ["A) Directly proportional to distance", "B) Directly proportional to square of distance", "C) Inversely proportional to the square of distance", "D) Inversely proportional to the cube of distance"], "ans": "C) Inversely proportional to the square of distance", "exp": "I ∝ 1/d². Doubling the distance reduces intensity to one-quarter. Clinically important in UV and IR therapy." }, { "q": "Q23. Maximum absorption of radiation occurs when rays fall on the surface at:", "opts": ["A) 45°", "B) 30°", "C) 60°", "D) 90° (perpendicular)"], "ans": "D) 90° (perpendicular)", "exp": "Lambert's Cosine Law: I = I₀ × cos θ. At 90°, cos 0° = 1 → maximum intensity. This governs UV and IR lamp positioning." }, { "q": "Q24. The correct order of EM spectrum from lowest to highest frequency is:", "opts": [ "A) Radio waves → UV → X-rays → Visible", "B) Radio waves → Infrared → Visible → UV → X-rays", "C) X-rays → UV → Visible → Infrared → Radio", "D) UV → Visible → Infrared → X-rays → Radio" ], "ans": "B) Radio waves → Infrared → Visible → UV → X-rays", "exp": "Frequency increases with decreasing wavelength. Remember: 'ROYGBIV' is visible spectrum; IR is below it, UV is above it." }, { "q": "Q25. Which UV band is most bactericidal?", "opts": ["A) UV-A", "B) UV-B", "C) UV-C", "D) All equally bactericidal"], "ans": "C) UV-C", "exp": "UV-C (200–290 nm) is most germicidal — peak bactericidal activity at ~254 nm. Used in wound sterilization." }, ] }, { "sec": "SECTION D — SOUND & ULTRASOUND", "qs": [ { "q": "Q26. Sound waves are classified as:", "opts": ["A) Transverse electromagnetic waves", "B) Longitudinal mechanical waves", "C) Transverse mechanical waves", "D) Electromagnetic waves"], "ans": "B) Longitudinal mechanical waves", "exp": "Sound involves compression and rarefaction of the medium, parallel to direction of propagation = longitudinal." }, { "q": "Q27. Ultrasound used in physiotherapy has a frequency of:", "opts": ["A) 20 Hz – 20 kHz", "B) 20 kHz – 100 kHz", "C) 0.5 – 3 MHz", "D) 10 – 50 MHz"], "ans": "C) 0.5 – 3 MHz", "exp": "Diagnostic US: 2–15 MHz. Therapeutic US: 1 MHz (deep tissues) and 3 MHz (superficial). Both are above audible range (>20 kHz)." }, { "q": "Q28. Ultrasound is produced by the:", "opts": ["A) Electromagnetic induction", "B) Piezoelectric effect", "C) Photoelectric effect", "D) Thermoelectric effect"], "ans": "B) Piezoelectric effect", "exp": "Piezoelectric crystals (quartz, PZT) deform under electrical stimulation, generating pressure waves = ultrasound." }, { "q": "Q29. The intensity of therapeutic ultrasound is expressed in:", "opts": ["A) Watts", "B) Hertz", "C) W/cm²", "D) Joules/cm"], "ans": "C) W/cm²", "exp": "Intensity = Power / Area. Typical therapeutic range: 0.5 – 3 W/cm². Above 3 W/cm² risks tissue damage." }, ] }, { "sec": "SECTION E — ELECTRICAL SAFETY", "qs": [ { "q": "Q30. Macroshock refers to electric current that:", "opts": ["A) Passes directly to the heart via catheter", "B) Is below threshold of perception", "C) Passes through body surface", "D) Is used in defibrillation only"], "ans": "C) Passes through body surface", "exp": "Macroshock = current enters through skin. Microshock = current applied directly to heart — far more dangerous at lower current levels." }, { "q": "Q31. The threshold of perception for AC current is approximately:", "opts": ["A) 0.1 mA", "B) 1 mA", "C) 10 mA", "D) 100 mA"], "ans": "B) 1 mA", "exp": "~1 mA AC causes a tingling sensation. Below this, current is subthreshold and not perceived." }, { "q": "Q32. 'Let-go current' is the current that causes:", "opts": ["A) First perception of tingling", "B) Cardiac fibrillation", "C) Sustained tetanic contraction preventing release", "D) Skin burns"], "ans": "C) Sustained tetanic contraction preventing release", "exp": "~10–20 mA AC causes sustained flexor muscle contraction. The person grips harder and cannot let go — hence 'let-go current.'" }, { "q": "Q33. Earth leakage current in medical electrical equipment must not exceed:", "opts": ["A) 100 µA", "B) 500 µA", "C) 1 mA", "D) 10 mA"], "ans": "B) 500 µA", "exp": "IEC 60601 standards mandate leakage current <500 µA to protect patients and operators." }, { "q": "Q34. Ventricular fibrillation can occur when AC current reaching the heart exceeds approximately:", "opts": ["A) 1 mA", "B) 10 mA", "C) 50–100 mA", "D) 500 mA"], "ans": "C) 50–100 mA", "exp": "50–100 mA AC passing transthoracically can cause VF. Microshock can cause VF with as little as 10–50 µA directly at the heart." }, { "q": "Q35. Which of the following best describes Class II electrical equipment?", "opts": ["A) Uses earth grounding for protection", "B) Uses double insulation instead of earth grounding", "C) Runs only on batteries", "D) Requires separate fuse protection"], "ans": "B) Uses double insulation instead of earth grounding", "exp": "Class I = earthed. Class II = double-insulated (no earth required). Class III = battery-operated (SELV). Class II is safer if earth connection fails." }, ] }, ] def render_mcqs(story, mcqs): for sec_data in mcqs: story.append(Paragraph(sec_data["sec"], H2)) story.append(HRFlowable(width="100%", thickness=1, color=MED_BLUE, spaceAfter=6)) for item in sec_data["qs"]: block = [] block.append(Paragraph(item["q"], MCQ_Q)) for opt in item["opts"]: if opt == item["ans"]: block.append(Paragraph(f'<font color="#1E7E34"><b>✓ {opt}</b></font>', MCQ_OPT)) else: block.append(Paragraph(opt, MCQ_OPT)) block.append(Paragraph(f"Explanation: {item['exp']}", MCQ_ANS)) block.append(Spacer(1, 3)) story.append(KeepTogether(block)) render_mcqs(story, mcqs) story.append(Spacer(1, 0.5*cm)) # Answer Key Table story.append(section_header("ANSWER KEY — AT A GLANCE", color=DARK_BLUE)) story.append(Spacer(1, 0.3*cm)) ans_rows = [["Q", "Ans", "Q", "Ans", "Q", "Ans", "Q", "Ans", "Q", "Ans"]] answers = ["C","C","B","C","B","C","C","B","C","D", "B","C","C","C","C","C","C","C","C","C", "C","C","B","C","B","B","C","B","C","C", "B","C","B","C","B"] row = [] for i, a in enumerate(answers, 1): row += [str(i), a] if len(row) == 10: ans_rows.append(row) row = [] if row: while len(row) < 10: row.append("") ans_rows.append(row) akt = Table(ans_rows, colWidths=[W/10]*10, repeatRows=1) akt.setStyle(TableStyle([ ('BACKGROUND', (0,0), (-1,0), DARK_BLUE), ('TEXTCOLOR', (0,0), (-1,0), colors.white), ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'), ('FONTSIZE', (0,0), (-1,-1), 9), ('FONTNAME', (0,1), (-1,-1), 'Helvetica'), ('BACKGROUND', (1,1), (1,-1), LIGHT_GREEN), ('BACKGROUND', (3,1), (3,-1), LIGHT_GREEN), ('BACKGROUND', (5,1), (5,-1), LIGHT_GREEN), ('BACKGROUND', (7,1), (7,-1), LIGHT_GREEN), ('BACKGROUND', (9,1), (9,-1), LIGHT_GREEN), ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.white, LIGHT_GREY]), ('BOX', (0,0), (-1,-1), 0.8, DARK_BLUE), ('INNERGRID', (0,0), (-1,-1), 0.3, MED_GREY), ('ALIGN', (0,0), (-1,-1), 'CENTER'), ('TOPPADDING', (0,0), (-1,-1), 5), ('BOTTOMPADDING', (0,0), (-1,-1), 5), ('FONTNAME', (1,1), (1,-1), 'Helvetica-Bold'), ('FONTNAME', (3,1), (3,-1), 'Helvetica-Bold'), ('FONTNAME', (5,1), (5,-1), 'Helvetica-Bold'), ('FONTNAME', (7,1), (7,-1), 'Helvetica-Bold'), ('FONTNAME', (9,1), (9,-1), 'Helvetica-Bold'), ('TEXTCOLOR', (1,1), (1,-1), GREEN), ('TEXTCOLOR', (3,1), (3,-1), GREEN), ('TEXTCOLOR', (5,1), (5,-1), GREEN), ('TEXTCOLOR', (7,1), (7,-1), GREEN), ('TEXTCOLOR', (9,1), (9,-1), GREEN), ])) story.append(akt) story.append(Spacer(1, 0.5*cm)) story.append(Paragraph( "Prepared for DPT 3rd Year Students | University of Health Sciences (UHS) | " "Based on: Jagmohan Singh — Textbook of Electrotherapy, Chapter 1", make_style('Footer', fontSize=8, textColor=colors.grey, alignment=TA_CENTER, fontName='Helvetica-Oblique') )) doc.build(story) print("PDF generated successfully:", OUTPUT) PYEOF