MCQ Bank
Which of the following is the correct Laplace transform of δ(t−3)?
- A) e3s
- B) s-3
- C) e3s /s
- D) e-3s
In solving the differential equation : y′′+3y′+2y=δ(t−1), y(0)=y′(0)=0 what is the Laplace transform of the right-hand side?
- A) 1/s
- B) δ(s−1)
- C) se-s
- D) e-s
Which of the following statements correctly defines the Dirac delta function δ(t)?
- A) It is infinite at t=0, zero elsewhere, and integrates to 1.
- B) It is zero for all t, including at t=0.
- C) It is a constant function with value 1 at t=0.
- D) It increases linearly from 0 to 1.
A voltage waveform starts at 0 V, jumps to 1 V at t = 1 s, to 2 V at t = 2 s, to 3 V at t = 3 s, and returns to 0 V at t = 4 s. Which of the following represents this signal using unit steps?
- A) u(t−1)+u(t−2)+u(t−3)−3u(t−4)
- B) u(t−1)+u(t−2)+u(t−3)
- C) u(t−1)−u(t−2)−u(t−3)+3 u(t−4)
- D) u(t−1)+2u(t−2)+3u(t−3)
Given the piecewise function: f(t) = \begin{cases} 0, & t < 2 \\ 5, & 2 \leq t < 4 \\ 0, & t \geq 4 \end{cases} Which of the following correctly represents f(t) using unit step functions?
- A) f(t)=5⋅u(t−2)
- B) f(t)=5⋅[u(t)−u(t−2)]
- C) f(t)=5⋅[u(t−2)+u(t−4)]
- D) f(t)=5⋅[u(t−2)−u(t−4)]
Given the piecewise function: \(f(t) = \begin{cases} 0, & t < 2 \\ 5, & 2 \leq t < 4 \\ 0, & t \geq 4 \end{cases} \) Which of the following correctly represents f(t) using unit step functions?
- A) f(t)=5⋅[u(t−2)+u(t−4)]
- B) f(t)=5⋅[u(t−2)−u(t−4)]
- C) f(t)=5⋅u(t−2)
- D) f(t)=5⋅[u(t)−u(t−2)]
Let $M$ be the Sigma algebra of measurable sets, then the Lebesgue measure m(E) of any set $E∈M$ is________.
- A) $μ(E)$
- B) a complex valued function
- C) $m^{∗}(A)$
- D) a real valued function
Intervals in R are always_______.
- A) closed
- B) non-measurable
- C) open
- D) measurable
For given $∅≠E⊆R$ and $ε>0$, there exists a closed set $F$________.
- A) $F-E≠ empty~ set$
- B) F=E
- C) $F⊇E$
- D) $F⊆E$
$${\text{The sequence of intervals }}\left( { - \infty ,b - \frac{1}{n}} \right]{\text{ (as }}n \to \infty ){\text{ converges to which of the following sets?}}$$
- A) $$\left( { - \infty ,b - 1} \right)$$
- B) $$\left( { - \infty ,b - 1} \right]$$
- C) $$\left( { - \infty ,b} \right]$$
- D) $$\left( { - \infty ,b} \right)$$
If the interval $\left( -\infty ,a\right)$ is measurable in $% %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion ,$ and $A\subseteq %TCIMACRO{\U{211d} }% %BeginExpansion \mathbb{R} %EndExpansion ,$ is a test set, then $m^{\ast }\left\{ A\cap \left( a,\infty \right) \right\} +m^{\ast }\left\{ A\cap \left( -\infty ,a\right) \right\}$ ____________.
- A) $\leq m^{\ast }\left( -\infty ,a\right)$
- B) $=m^{\ast }\left( -\infty ,a\right)$
- C) $=m^{\ast }\left( a,\infty \right)$
- D) $=m^{\ast }\left( A\right)$
An open set U in R is measurable, because it can be expressed as________.
- A) countable union of open sets
- B) arbitrary union of open sets
- C) arbitrary intersection of open sets
- D) countable intersection of open sets
$${\text{Which of the following statements is true if A}} \subset \bigcup\limits_{n = 1}^\infty {{I_n}} {\text{?}}$$
- A) $$\sum\limits_{n = 1}^\infty {l({I_n})} = {m^*}(A) + \varepsilon$$
- B) $$\sum\limits_{n = 1}^\infty {l({I_n})} > {m^*}(A) + \varepsilon$$
- C) $$\sum\limits_{n = 1}^\infty {l({I_n})} < {m^*}(A) + \varepsilon$$
- D) $$\sum\limits_{n = 1}^\infty {l({I_n})} = {m^*}(A)$$
For all $E⊆R$, there is a $G_{δ}$ set $G⊇E$, such that_______.
- A) $m*(G-E)>0$
- B) $m*(G-E)$ is not defined
- C) $m*(G-E)<0$
- D) $m*(G-E)=0$
For all $E⊆R$, there is a $F_{σ}$ set $F⊆E$, such that_______.
- A) $m*(E-F)$ is not defined
- B) $m*(E-F)=0$
- C) $m*(E-F)<0$
- D) $m*(E-F)>0$
For given $∅≠E⊆R$ and $ε>0$, there exists an open set $O$________.
- A) $O⊇E$
- B) $E⊆O$
- C) $E-O≠∅$
- D) $E=O$
If the non-empty sets say $A,B$ are measurable then $A-B$__________.
- A) may or may not measurable
- B) implies $m^{∗}(A-B)<ε$
- C) is also measurable
- D) is not measurable
If a set in Euclidean space is translated by a fixed amount in any direction, what happens to its Lebesgue measure?
- A) It decreases.
- B) It remains the same.
- C) It becomes infinite.
- D) It increases.
A set $E$ is a Borel set if it can be expressed as_____________.
- A) neither countable union nor intersection of open or closed sets
- B) countable intersection of open (closed) sets
- C) either countable union or intersection of open or closed sets
- D) countable union of open (closed) sets
$If~\{E_{n}\}~be~an~increasing~sequence~of~measurable~sets~then$
- A) $E_{1}\neq E_{2}\neq E_{1}...$
- B) $...E_{3}\subseteq E_{2} \subseteq E_{1} \subseteq$
- C) $E_{1}\subseteq E_{2} \subseteq E_{3} \subseteq ...$
- D) $E_{1}-E_{1}\subseteq E_{1}-E_{2}\subseteq E_{1}-E_{3}\subseteq... E_{1}-E_{n}\subseteq$....