**Model for ECE:
Direct Theory question:**

1. A triangular-square wave generator uses

* A sine wave oscillator and a comparator

* An integrator and a comparator

* A diffrentiator and comparator

* A sine wave oscillator and a clipper

2. An amplifier has two identical cascaded stages. Each stage has a BW of 20KHz. The overall BW

shall be

* 10KHz

* 12.9KHz

* 20KHz

* 28.3HHz

**Direct numerical problem:**

- A parabolic dish antenna has a diameter of 1m. the maximum possible ideal gain of the antenna at a wavelength 3.14cm is

* 20 dB

* 30 dB

* 40 dB

* 50 dB - The frequency deviation produced in a VHF carrier by a signal of 100Hz is 50KHz. The frequency modulation is

100 radians

250 radians

500 radians

750 radians**Application based theoretical or numerical problem:**

- Which one of the pulses has the same form in time domain as well as in frequency domain

Rectangular

Exponenetial

Triangular

Gaussian

- Good voice reproduction via PCM requires 128 quantisation levels. If the BW of voice channel is 4KHz then data rate is

256 Kbps

128 Kbps

56 Kbps

28 Kbps

- Match the following:

1. List 1 List2

A. Thyristor 1. Second break down

B. MOSFET 2. Large on-state drop

C. IGBT 3. Small on state drop

D. BJT 4. Slow deviceCodes:

(a) A-4, B-3, C-2, D-1 (b) A-1, B-2, C-3, D-4

(c) A-4, B-2, C-3, D-1 (d) A-1, B-3, C-2, D-4

- List 1 List2
A. Free and forced response 1. Discrete time systems

B. Z transform 2. Dirichlet conditions

C. Probability theory 3. Non-homogenous differential equation

d. Fourier series 4. Random processCodes:

(a) A-1, B-3, C-2, D-4 (b) A-3, B-1, C-2, D-4

(c) A-1, B-3, C-4, D-2 (d) A-3, B-1, C-4, D-2Assertion and reasoning type:

The following item consists of two statements labeled as Assertion A and the other as Reason R. Use the following codes:

(a) Both A&R are individually true and R is the correct explanation of A

(b) Both A & R are individually true and R is not the correct explanation of A

(c) A is true and R is false

(d) A is false and R is true

- AEvery materials has a different value of energy band gap except metals which have no band gap

R The energy band gap is decided by the equilibrium lattice constant, which is different in different materials.

- AOp-amp are commonly used in instrumentation

R Op-amps do not load the circuit due to their very high input impedance**Problem based on circuits and graphs:**Some examples:

For circuits: HW rectifier, voltmeter, RC or RLC or RL transients, feedback systems, clipper, clamper, transistor biasing,555 circits, logic gates, counters, bridges and wattmeters.

Graphs: Frequency response H(s),open loop gain from root loci, Nyquist plot, transfer functions etc