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EC : ELECTRONICS AND COMMUNICATION ENGINEERING
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The c urrent ib through the base of a silicon npn transistor is
10.1 cos(10000 t) mA
. At 300 K,
the r in the small signal model of the transistor is
ib
r r0 B C
E
(A) 250 (B) 27.5 © 25 (D) 22.5
Q.2 The power spectral density o f a real process X(t) for positive frequencies is shown below. The
values of E[X
2
(t)] and
E[X(t)]
, respectively, are
SX(ω) 400 d(w-104
)
ω (103 9 10 11 rad/s)
6
0
(A) 6000/π, 0 (B) 6400/π, 0
© 6400/π, 20/( 2) (D) 6000/π, 20/( 2)
Q.3 In a baseband communications link, frequencies upto 3500 Hz are used for signaling. Using a
raised cosine pulse with 75% excess bandwidth and for no inter-symbol interference, the maximum
possible signaling rate in symbols per second is
(A) 1750 (B) 2625 © 4000 (D) 5250
Q.4 A plane wave propagating in air with (8 ˆ 6 ˆ 5 ˆ ) V/m j( t 3x 4 y)
x y z E a a a e
w
is incident on a
perfectly conducting slab positioned at
x 0
. The
E
field of the reflected wave is
(A)
( 8 ˆ 6 ˆ 5 ˆ ) V/m j( t 3x 4 y)
x y z a a a e
w
(B) ( 8 ˆ 6 ˆ 5 ˆ ) V/m j( t 3x 4y)
x y z a a a e
w
©
( 8 ˆ 6 ˆ 5 ˆ ) V/m j( t 3x 4y)
x y z a a a e
w
(D)
( 8 ˆ 6 ˆ 5 ˆ ) V/m j( t 3x 4 y)
x y z a a a e
w
Q.5 The electric field of a uniform plane electromagnetic wave in f ree space, along the positive
x direction, is given by
j x
y z E a j a e
25 10 ˆ ˆ
. The frequ
Q.56 If (1.001)
1259
= 3.52 and (1.001)2062
= 7.85, then (1.001)3321
=
(A) 2.23 (B) 4.33 © 11.37 (D) 27.64
Q.57 C hoose the most appropriate alternative from the options given below to complete the following
sentence:
If the tired soldier wanted to lie down, he ___ the mattress out on the balcony.
(A) should take
(B) shall take
© should have taken
(D) will have taken
Q.58 Choose the most appropriate word from the options given below to complete the following
sentence:
Given the seriousness of the situation that he had to face, his ___ was impressive.
(A) beggary (B) nomenclature © jealousy (D) nonchalance
Q.59 Which one of the following options is the closest in meaning to the word given below?
Latitude
(A) Eligibility (B) Freedom © Coercion (D) Meticulousness
Q.60 One of the parts (A, B, C, D) in the sentence given below contains an ERROR. Which one of the
following is INCORRECT?
I requested that he should be given the driving test today instead of tomorrow.
(A) requested that
(B) should be given
© the driving test
(D) instead of tomorrow
Q. 61 - Q. 65 carry two marks each.
Q.61 One of the l egacies of the Roman legions was discipline. In the legions, military law prevailed
and discipline was brutal. Discipline on the battlefield kept units obedient, intact and fighting,
even when the odds and conditions were against them.
Which one of the following statements best sums up the meaning of the above passage?
(A) Thorough regimentation was the main reason for the efficiency of the Roman legions even in
adverse circumstances.
(B) The legions were treated inhumanly as if the men were animals.
© Discipline was the armies’ inheritance from their seniors.
(D) The harsh discipline to which the legions were subjected to led to the odds and conditions being
against them. 2012 ELECTRONICS & COMMN. ENGG. - EC
EC-A 14/20
Q.62 Raju has 14 currency notes in his pocket consisting of only Rs . 20 notes and Rs. 10 notes. The total
money value of the notes is Rs. 230. The number of Rs. 10 notes that Raju has is
(A) 5 (B) 6 © 9 (D) 10
Q.63 There are eight bags of rice looking alike, seven of which have equal weight