Definition of integration MCQs With Answer provides B. Pharm students a clear, focused review of integral calculus concepts and their pharmaceutical applications. This Student-friendly post covers key terms like definite integral, indefinite integral, fundamental theorem of calculus, substitution, integration by parts, numerical integration, and AUC in pharmacokinetics. Designed for B. Pharm students, the content links mathematical definitions to drug dosage calculations, area under the curve (AUC), and rate processes in pharmaceutics. These integration MCQs with answers boost understanding, exam readiness, and practical problem-solving skills. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. What is the definition of an indefinite integral?
- A numerical value representing the area under a curve between two points
- A family of functions whose derivative gives the integrand
- A method for approximating definite integrals using rectangles
- A special type of differential equation solution method
Correct Answer: A family of functions whose derivative gives the integrand
Q2. Which statement best defines a definite integral?
- An antiderivative of a function without limits
- The signed area under a curve between two specified limits
- A sequence of approximations converging to a derivative
- A formula for integrating rational functions only
Correct Answer: The signed area under a curve between two specified limits
Q3. What does the Fundamental Theorem of Calculus link?
- Limits and infinite series
- Differentiation and integration
- Partial fractions and trigonometric substitution
- Numerical methods and error estimation
Correct Answer: Differentiation and integration
Q4. In pharmacokinetics, what does AUC represent?
- Absolute uptake coefficient of a drug
- Area under the plasma concentration-time curve
- Average urinary clearance
- Approximate unbound concentration
Correct Answer: Area under the plasma concentration-time curve
Q5. Which integration technique is most appropriate for ∫ x e^{x} dx?
- Partial fractions
- Integration by parts
- Trigonometric substitution
- Direct antiderivative lookup only
Correct Answer: Integration by parts
Q6. How is the area under a concentration-time curve from 0 to ∞ commonly estimated?
- Using repeated differentiation
- Numerical integration plus extrapolation from last measured point
- Solving a linear algebraic equation
- Applying the Laplace transform only
Correct Answer: Numerical integration plus extrapolation from last measured point
Q7. Which substitution is useful for ∫ (2x)/(x^2+1) dx?
- u = x^2 + 1
- u = 2x
- u = 1/x
- u = arctan x
Correct Answer: u = x^2 + 1
Q8. What is an improper integral?
- An integral with a discontinuous integrand or infinite limits
- An integral that cannot be solved by substitution
- An integral only solvable by numerical methods
- An integral representing steady-state concentration
Correct Answer: An integral with a discontinuous integrand or infinite limits
Q9. Which numerical method uses parabolic arcs to approximate integrals?
- Trapezoidal rule
- Simpson’s rule
- Left Riemann sum
- Monte Carlo integration
Correct Answer: Simpson’s rule
Q10. For a first-order elimination process C(t)=C0 e^{-kt}, what is the integral of C(t) from 0 to ∞?
- C0/k
- C0*k
- k/C0
- Zero
Correct Answer: C0/k
Q11. Which rule gives the derivative of an integral with a variable upper limit?
- Integration by parts
- Fundamental theorem of calculus
- Partial fraction decomposition
- Mean value theorem for integrals
Correct Answer: Fundamental theorem of calculus
Q12. When integrating rational functions, what technique often simplifies the integrand?
- Integration by parts
- Partial fraction decomposition
- Trigonometric substitution for linear terms
- Using the Laplace transform directly
Correct Answer: Partial fraction decomposition
Q13. The indefinite integral ∫ cos x dx equals:
- sin x + C
- -sin x + C
- cos x + C
- -cos x + C
Correct Answer: sin x + C
Q14. Which integral property helps split integrals over adjacent intervals?
- Linearity of integration and additivity over intervals
- Integration by substitution
- Integration by parts
- Change of variables only for improper integrals
Correct Answer: Linearity of integration and additivity over intervals
Q15. For definite integrals, linearity refers to:
- ∫(a f + b g) = a ∫f + b ∫g
- Changing limits flips sign only
- Using only constant multiples is allowed
- Integration and differentiation commute always
Correct Answer: ∫(a f + b g) = a ∫f + b ∫g
Q16. Which substitution is best for ∫ sin^3 x cos x dx?
- u = sin x
- u = cos x
- u = tan x
- u = sin^2 x
Correct Answer: u = sin x
Q17. Integration by parts is derived from which product rule?
- Differentiation of a quotient
- Differentiation of a product
- Chain rule
- Leibniz rule for higher derivatives
Correct Answer: Differentiation of a product
Q18. How is clearance (Cl) related to AUC for an IV bolus?
- Cl = Dose × AUC
- Cl = Dose / AUC
- Cl = AUC / Dose
- Cl = Dose + AUC
Correct Answer: Cl = Dose / AUC
Q19. Which integral represents the convolution of input function f(t) with system response g(t)?
- ∫ f(t) g(t) dt from 0 to ∞
- ∫ f(τ) g(t-τ) dτ from 0 to t
- ∫ f(t) dt × ∫ g(t) dt
- ∫ f(t)/g(t) dt
Correct Answer: ∫ f(τ) g(t-τ) dτ from 0 to t
Q20. Which method is preferred to evaluate ∫ dx/(x^2-1)?
- Trigonometric substitution
- Partial fraction decomposition
- Integration by parts
- Simpson’s rule
Correct Answer: Partial fraction decomposition
Q21. What is the integral of 1/x dx (x>0)?
- 1/x + C
- ln |x| + C
- e^x + C
- arctan x + C
Correct Answer: ln |x| + C
Q22. In drug release kinetics, which integral helps compute cumulative drug released over time?
- Definite integral of release rate from 0 to t
- Indefinite integral without constant
- Derivative of plasma concentration
- Inverse Laplace transform only
Correct Answer: Definite integral of release rate from 0 to t
Q23. For definite integrals, reversing the limits changes the sign. True or false?
- True
- False
- Only true for symmetric limits
- Only true for improper integrals
Correct Answer: True
Q24. Which integrand is best handled by trigonometric substitution?
- 1/(x+1)
- 1/√(a^2 – x^2)
- e^{x^2}
- ln x
Correct Answer: 1/√(a^2 – x^2)
Q25. What is the integral ∫ 0 to T k e^{-kt} dt equal to?
- e^{-kT}
- 1 – e^{-kT}
- kT e^{-kT}
- T/k
Correct Answer: 1 – e^{-kT}
Q26. When using u-substitution, dx is replaced by:
- du / (du/dx)
- du × (du/dx)
- du / (dx/du)
- du
Correct Answer: du / (du/dx)
Q27. Which integrand requires using the substitution u = tan x? (Hint: involves sec^2 x)
- ∫ sec^2 x dx
- ∫ sin x dx
- ∫ cos x dx
- ∫ 1/x dx
Correct Answer: ∫ sec^2 x dx
Q28. The mean residence time (MRT) involves which integral expression?
- MRT = ∫ t C(t) dt / ∫ C(t) dt
- MRT = ∫ C(t) dt × ∫ t dt
- MRT = ∫ C(t)/t dt
- MRT = ∫ dC/dt dt
Correct Answer: MRT = ∫ t C(t) dt / ∫ C(t) dt
Q29. For integrating ∫ e^{ax} dx, the antiderivative is:
- (1/a) e^{ax} + C
- a e^{ax} + C
- e^{ax} + C
- ln(e^{ax}) + C
Correct Answer: (1/a) e^{ax} + C
Q30. Which statement about numerical integration errors is correct?
- Simpson’s rule often gives higher accuracy than trapezoidal for smooth functions
- Trapezoidal rule is always more accurate than Simpson’s rule
- Numerical methods produce no error with irregular functions
- Errors cannot be estimated
Correct Answer: Simpson’s rule often gives higher accuracy than trapezoidal for smooth functions
Q31. Which integral is evaluated using the substitution x = a sec θ?
- ∫ dx/√(x^2 – a^2)
- ∫ dx/√(a^2 – x^2)
- ∫ dx/(x^2+1)
- ∫ e^{x^2} dx
Correct Answer: ∫ dx/√(x^2 – a^2)
Q32. What is the antiderivative of 2x/(1+x^2)?
- ln(1+x^2) + C
- arctan x + C
- 1/(1+x^2) + C
- x^2 + C
Correct Answer: ln(1+x^2) + C
Q33. When is it appropriate to use integration by parts twice?
- For integrands like x^2 e^{x} or x^2 cos x
- When integrand is rational with linear denominator
- Only for definite integrals
- Never; use substitution instead
Correct Answer: For integrands like x^2 e^{x} or x^2 cos x
Q34. To compute AUC from discrete concentration-time points, which technique is commonly used?
- Analytical integration only
- Linear trapezoidal rule
- Integration by parts
- Partial fractions
Correct Answer: Linear trapezoidal rule
Q35. Which integral represents the total amount eliminated from time 0 to t for elimination rate k and concentration C(t)?
- ∫ 0 to t k C(t) dt
- ∫ 0 to t C(t)/k dt
- C(t)/k
- k ∫ 0 to t dt
Correct Answer: ∫ 0 to t k C(t) dt
Q36. Which antiderivative corresponds to ∫ sec^2 x dx?
- tan x + C
- sec x + C
- sin x + C
- ln |sec x| + C
Correct Answer: tan x + C
Q37. For ∫ (ax+b) / (cx+d) dx, what method simplifies the integral?
- Long division followed by simple substitution
- Trigonometric substitution
- Integration by parts repeatedly
- Simpson’s rule
Correct Answer: Long division followed by simple substitution
Q38. Which integral test determines convergence of improper integrals?
- Comparison test with known convergent integrals
- Integration by parts always
- Trapezoidal error test
- Simpson convergence theorem
Correct Answer: Comparison test with known convergent integrals
Q39. Which integral equals zero by symmetry when integrand is odd and limits are symmetric?
- ∫_{-a}^{a} f(x) dx if f is even
- ∫_{-a}^{a} f(x) dx if f is odd
- ∫_{0}^{a} f(x) dx if f is odd
- None of the above
Correct Answer: ∫_{-a}^{a} f(x) dx if f is odd
Q40. When evaluating ∫ dx/(x^2+1), the antiderivative is:
- ln|x| + C
- arctan x + C
- tan x + C
- 1/(1+x^2) + C
Correct Answer: arctan x + C
Q41. In pharmacokinetics, the clearance concept can be derived from which integral relation?
- Area under the curve relating dose and systemic exposure
- Integral of volume over time
- Derivative of concentration at t=0
- Integral of molecular weight
Correct Answer: Area under the curve relating dose and systemic exposure
Q42. Which substitution simplifies ∫ dx/(√(x^2+a^2))?
- x = a sin θ
- x = a tan θ
- x = a cos θ
- x = a sec θ
Correct Answer: x = a tan θ
Q43. Which statement best describes the linearity of definite integrals?
- ∫ f+g = ∫ f × ∫ g
- ∫ (c f) = c ∫ f
- ∫ f^2 = (∫ f)^2
- Linearity applies only to improper integrals
Correct Answer: ∫ (c f) = c ∫ f
Q44. The area under a curve computed by Riemann sums becomes exact as:
- The number of partitions approaches zero
- The number of partitions approaches infinity and mesh size tends to zero
- The function becomes discontinuous
- The integrand increases without bound
Correct Answer: The number of partitions approaches infinity and mesh size tends to zero
Q45. Which integral is easiest evaluated by recognizing a derivative of a logarithm?
- ∫ (2x)/(1+x^2) dx
- ∫ x^2 dx
- ∫ e^{x} dx
- ∫ sin x dx
Correct Answer: ∫ (2x)/(1+x^2) dx
Q46. In calculating AUC using the trapezoidal rule, what assumption is made between measured points?
- Concentration varies exponentially
- Concentration varies linearly between points
- Concentration stays constant
- Concentration follows a parabolic path always
Correct Answer: Concentration varies linearly between points
Q47. What is the antiderivative of cosh x?
- sinh x + C
- cosh x + C
- e^{x} + C
- tanh x + C
Correct Answer: sinh x + C
Q48. For integrals containing √(a^2 – x^2), which trig substitution is used?
- x = a sec θ
- x = a tan θ
- x = a sin θ
- x = a cosh u
Correct Answer: x = a sin θ
Q49. Which integral technique helps evaluate ∫ e^{x} sin x dx?
- Single substitution
- Integration by parts twice
- Partial fractions
- Trigonometric substitution
Correct Answer: Integration by parts twice
Q50. How does integration apply to calculating cumulative bioavailability from rate data?
- By differentiating the rate to get concentration
- By integrating the absorption rate over time to get total absorbed
- By taking the average of rate values only
- By applying partial fractions to the rate directly
Correct Answer: By integrating the absorption rate over time to get total absorbed

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