# How to Excel in GATE

### How to Excel in GATE

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How to excel in GATE? (EC example)

There is a widespread notion that GATE is not easy to crack, and that it is very difficult to get a good score in GATE. Is this true?

The answer is an emphatic NO!. You only need proper preparation to excel in GATE. You don’t need to be a genius to get a rank under 100. You only need to be smart enough to prepare properly, along with a strong motivation towards excellence.

For an excellent performance in GATE, two things are essential:

A comprehensive understanding of concepts
Extensive practice

Let us consider the importance of concepts with a simple example:

The power of the signal x(t)=2 cos100πt-5 sin100πt is _____________

The question is quite straightforward. To answer this question, you need to know the following concepts:
• Power of a sinusoid
• Orthogonality of sin and cosine signals of the same frequency
• Power of a sum of orthogonal signals
If you know these three concepts, the answer is direct. You’d probably have encountered such questions in your tests/exams. Now consider the next example:

The power of the signal x(t)=2 cos100πt-5sin[(100πt-π/3)] is _____________

This question adds phase shift as a new parameter to the previous question. Now we cannot add the powers of the two components of x(t) directly. To answer this question, you need to know

• The formula for sin(A-B), so that x(t) can be expressed once again in terms of orthogonal components, or
• Phasor diagram

Thus, the second question adds something extra to the first one, to make it more challenging. This is typical of GATE questions. In fact, the same concept can be tested in a broader context. Consider the following example:

The signal x(t)=cos100πt+2 sin[(120πt-π/3)] is SSB-USB modulated, with both the in-phase and quadrature carriers having an amplitude of 3V. The power of the modulated signal is ____________

To answer this question, you should know

• Whether the two components of x(t) are orthogonal
• To calculate the power of x(t), and the relation between the power of the message signal and modulated signal in SSB, or
• To plot the power spectrum of the modulated signal and find its power.
From the examples discussed, we can make some observations:

• A typical GATE question requires you to know many different concepts.
• You should also know how to connect the different concepts together to get the correct answer. This is where practice helps.
• Concepts in fundamental subjects like signals and systems form the basis of those in advanced subjects like communication. So you need to have a proper focus on fundamental subjects.
The next section summarizes the ideal approach to GATE(EC) preparation

Next: The ideal approach to GATE preparation