Brain Teasers
Few Brain Teasers in ECE/TCE/IN Department
1. 2.
1 -t2 1.The integral (-t) t 2 e dt evaluates to (a) -4/3 (b) 0 (c) 4/3 (d) – 2/3 Point charges = 1 nc and = 2 nc are at a distance apart. Which of the following statements are incorrect (a) force on is repulsive (b) The force on is the same in magnitude as that on Q1 (c) As the Distance between them decreases, the force on Q1 increases linearly. (d) The force on is along the line joining them (e) A point charge = -3 nc located at midpoint between Q1 and Q2 experience no net force Suppose uniform field exists in room in which you are working , such that lines of force are Horizontal and at right an gles to one wall. As you walk toward wall from which the lines of force emerge into room, are you walking toward ? (a) Points of higher potential (b) Points of lower potential (c) Points of same potential Which of the following operations are not associative (a) inhibition (b) NOR (c) implication Assuming ‘n’ element Boolean Algebra, how many functions are there for ‘m’ variables ? In Transmission Lines, why we are considering R, L, G, C as Distributed parameters where as in normal wires we are not considering them as distributed : t sin ( T cos( Tt 2 2 1-4 tT Find the Fourier transform of the following signal ( Tt How long does it take an average electron to drift 1ìm in pure ‘Si’ at electric field of V/cm (a) 0.74 Psec (b) 10 Psec (c) 0.1 Psec (d) None
3.
4. 5. 6. 7. 8.
9.
Cos
t c
+ m(t) + H(t) Sin c t
s(t)
1 m(t) = - 1000 1000
i. Lowest positive 5 = 2ð × 10 rad/sec c (a) Find Highest frequency component of s(t) 2. 3.
6 X e -x . dx = ? (a) 0 (b) 320 (c) 160 Consider the circuit given below. Also,
2
(b) Find the Band width of s(t)
(d) 960 i2 R1 Vi i1 + V_ Ao + _ V o
_
(a) A F = V o Vi (amplification with feedback) _ (b) A o = V o/ V (amplification without feedback) A o (c) Input resistance to A o is much greater than R 1 and R 2 is large and negative . (d) Output resistance of A o is
1. 2.
1 -t2 1.The integral (-t) t 2 e dt evaluates to (a) -4/3 (b) 0 (c) 4/3 (d) – 2/3 Point charges = 1 nc and = 2 nc are at a distance apart. Which of the following statements are incorrect (a) force on is repulsive (b) The force on is the same in magnitude as that on Q1 (c) As the Distance between them decreases, the force on Q1 increases linearly. (d) The force on is along the line joining them (e) A point charge = -3 nc located at midpoint between Q1 and Q2 experience no net force Suppose uniform field exists in room in which you are working , such that lines of force are Horizontal and at right an gles to one wall. As you walk toward wall from which the lines of force emerge into room, are you walking toward ? (a) Points of higher potential (b) Points of lower potential (c) Points of same potential Which of the following operations are not associative (a) inhibition (b) NOR (c) implication Assuming ‘n’ element Boolean Algebra, how many functions are there for ‘m’ variables ? In Transmission Lines, why we are considering R, L, G, C as Distributed parameters where as in normal wires we are not considering them as distributed : t sin ( T cos( Tt 2 2 1-4 tT Find the Fourier transform of the following signal ( Tt How long does it take an average electron to drift 1ìm in pure ‘Si’ at electric field of V/cm (a) 0.74 Psec (b) 10 Psec (c) 0.1 Psec (d) None
3.
4. 5. 6. 7. 8.
9.
Cos
t c
+ m(t) + H(t) Sin c t
s(t)
1 m(t) = - 1000 1000
i. Lowest positive 5 = 2ð × 10 rad/sec c (a) Find Highest frequency component of s(t) 2. 3.
6 X e -x . dx = ? (a) 0 (b) 320 (c) 160 Consider the circuit given below. Also,
2
(b) Find the Band width of s(t)
(d) 960 i2 R1 Vi i1 + V_ Ao + _ V o
_
(a) A F = V o Vi (amplification with feedback) _ (b) A o = V o/ V (amplification without feedback) A o (c) Input resistance to A o is much greater than R 1 and R 2 is large and negative . (d) Output resistance of A o is