Quiz Electronics Engineering 13 Aug 2020

Quiz Electronics Engineering
Exam: NIC
Topic: Miscellaneous
Date: 13/08/2020

Each Question carries 1 Mark
Negative Marking: 1/4
Time: 10 Minutes

Q1. Assertion(A): The total energy of an energy signal falls between the limits 0 and ∞.
Reason(R): The average power of an energy signal is zero.
(a) Both A and R are True and R is the correct explanation of A.
(b) Both A and R are True but R is not the correct explanation of A.
(c) A is True but R is False.
(d) A is False but R is True.

Q2. The analog signal m(t) is given below
m (t) = 4cos100πt + 8sin200πt + cos300πt, the Nyquist sampling rate will be:
(a) 1/100
(b) 1/200
(c) 1/300
(d) 1/600

Q3. Which is not a peripheral device?
(a) Modem
(b) Pen Drive
(c) Main memory chips
(d) Visual Display Unit

Q4. Which of the following device is not an example of embedded system?
(a) Mobile
(b) Digital Camera
(c) Tablet
(d) Microprocessor

Q5. In an AC circuit Isinϕ is called
(a) wattless component of current
(b) reactive component of current
(c) quadrature component of current
(d) All of the above

Q6. Which of the following groups constitute basic logic gates?
(a) AND, OR, NOT.
(b) AND, OR
(c) NOR, NAND
(d) XOR, XNOR

Q7. Two thin parallel wires are carrying current along the same direction. The force experienced by one due to the other is
(a) parallel to the lines.
(b) perpendicular to the lines and repulsive.
(c) perpendicular to the lines and attractive.
(d) zero.

Q8. Which diode is used for measuring light intensity?
(a) Junction diode
(b) Varactor diode
(c) Tunnel diode
(d) Photo diode

Q9. The convolution x(n)* 𝛿(n – n_o) is equal to
(a) x(n – n_o)
(b) x(n + n_o)
(c) x(n_o)
(d) x(n)

Q10. The Flip-Flop circuit is …
(a) unstable
(b) bistable
(c) monostable
(d) multi-stable

SOLUTIONS

S1. Ans.(b)
Sol. For any energy signal, Energy is finite and average Power is zero.
⇒ P = lim┬(T →∞ )⁡〖E/T〗 = 0
All the finite duration and bounded signals are Energy Signal.

S2. Ans. (c)
Sol. Given:
m (t) = 4cos100πt + 8sin200πt + cos300πt,
We know that, Nyquist sampling frequency is
fs = 2fm where, fm is highest frequency component

Now, fm is highest in 3rd part
⇒ 2πfmt = 300πt
⇒ fm = 150 Hz
∴ fs = 2 x 150 = 300 Hz
So, Nyquist Sampling Rate = 1/f_s = 1/300

S3. Ans.(c)
Sol. The devices which are connected in any way externally to the computer is called Peripheral Device. Here, Main memory chip is present inside the computer to store the data.

S4. Ans.(d)
Sol. An embedded system is a computer system, made from a combination of hardware and software, that is used to perform a specific task. It is present inside a larger mechanical and electrical appliances. Microprocessor is not an embedded system because it can perform more than one function or task at a time.

S5. Ans. (d)
Sol.

From Phasor diagram, we get that Isinϕ is 90° displaced w.r.t active component Icosϕ. So, it is called “Quadrature component of the current”. This Isinϕ doesn’t do any work, it just moves back and forth. Hence, it is called reactive component of current. It is not a useful power so it is also called “Wattless Power”.

S6. Ans (a)
Sol.
AND, OR, NOT are the basic logic gates.
NAND, NOR are Universal logic gates.
X-OR, X-NOR are the derived gates.

S7. Ans.(c)
Sol. Force is always perpendicular to the current carrying line and Force will be attractive if both the current carrying wire have same direction of flow of current and repulsive if current flow in both wire in opposite direction.

S8. Ans.(d)
Sol. Photo diode works on the principle of Photoelectric effect. In Reverse bias, it absorbs photons falling on the junction of diode and converts it into current. So, Photo diode is used for measuring intensity of light from above mentioned diodes.

S9. Ans.(a)
Sol.
⇒ x(n)* 𝛿(n – n_o) □(↔┴( F.T ) ) x(n – n_o)

S10. Ans (b)
Sol. A flip-flop or latch is a circuit that has two stable states and can be used to store state information. A flip-flop is also called as a Bistable Multivibrator.

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