IndiaBIX

Electronics and Communication Engineering - Electronic Devices and Circuits

Exercise : Electronic Devices and Circuits - Section 7
26.
An RLC series circuit has R = 30 Ω, XL = 30 Ω and XC = 30 W. Its impedance is
30 ∠0°.
30 ∠45°
42.42 ∠45°
90 ∠45°.
Answer: Option
Explanation:

Z = 30 + j (30 - 30) = 30∠0 Ω.

27.
R, L and C are in parallel. The circuit is switched on to a constant current source I at t = 0. At t = ∞ the current through inductance is I.
True
False
Answer: Option
Explanation:

At t = ∞ inductance behaves as short-circuit.

28.
A 2 mH inductor with some initial current can be represented as shown below, where s is the Laplace transform variable. The value of initial current is
0.5 A
1.0 A
2.0 A
0.0 A
Answer: Option
Explanation:

Initial current iL(0+) or

.

29.
As temperature increases, the temperature coefficient of metals increases.
True
False
Answer: Option
Explanation:

As temperature increases the temperature coefficient of metal decreases.

30.
In a 3 phase system, the zero sequence component of line to line voltages is zero
if line to line voltages are balanced
if line to line voltages are unbalanced
if line to line voltages are balanced or unbalanced
if degree of unbalanced in line to line voltages is small
Answer: Option
Explanation:

Zero sequence component of line to line voltage is always zero irrespective of degree of unbalance.

Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers