List of practice Questions

Today, India has become the fourth country in the world to touch the surface of the moon. This success becomes even greater when we look at the place from where India had started its journey. There was a time when India did not have the required technology and there was no support either. We used to be among the ‘Third World’ countries, standing in the third row. Today, India has become the fifth largest economy in the world. Today, from trade to technology, India is among the countries standing in the first row. In this journey from third row to first row, institutions like ISRO have played a major role. Today, you have taken ‘Make in India’ to the moon.
I have seen the photo in which our moon lander has firmly set its foot on the moon like Angad. On one hand is the confidence of Vikram while on the other hand is the bravery of Pragyan. Our Pragyan is continuously leaving its footprints on the moon. The pictures taken from different cameras, which have just been released, and I have had the privilege of seeing, are indeed amazing. For the first time, since the beginning of human civilization, for the first time in the history of lakhs of years on the earth, man is looking at the pictures of that place with his own eyes. India has done the work of showing these pictures to the world! All the scientists like you have done it. Today, the whole world is acknowledging the significance of India’s scientific spirit, our technology and our scientific temperament. Chandrayaan Maha Abhiyan is a success not only for India but for the entire humanity.
[Extracted from the Speech made by the Prime Minister of India Shri. Narendra Modi on the occasion of the landing of Chandrayaan 3 on 26th August 2023]

If a small single-turn loop antenna has a radiation resistance of 0.04 \(\Omega\), how many turns are needed to produce a radiation resistance of 1 \(\Omega\)?

If in a rectangular waveguide for which \(a=2b\), the cutoff frequency for TE\(_{01}\) mode is 12 GHz, the cutoff frequency for TM\(_{11}\) is

Which one of the following is not true of a lossless line?

Which of the following function does not satisfy the wave equation?

The Maxwell's equation \( \oint \vec{E} \cdot d\vec{l} \) is equal to

A loop is rotating about the y-axis in a magnetic field \( B = B_0 \sin \omega t \ \hat{a}_z \text{ Wb/m}^2 \). The voltage induced in the loop is due to (Note: \(\hat{a}_z\) means the B field is in the z-direction. The loop rotates about y-axis.)

According to Parseval's theorem the energy spectral density curve is equal to the area under (The question is phrased a bit oddly. "energy spectral density curve is equal to the area under..." Parseval's theorem relates energy in time domain to energy in frequency domain. The area under the Energy Spectral Density (ESD) curve *is* the total energy.)

Flat-top sampling leads to

Which one of the following is true?

As the bandwidth approaches infinity, the channel capacity becomes (Referring to Shannon-Hartley theorem: \(C = B \log_2(1 + S/N)\))

The 18th G20 Summit, in which the heads of states and governments will meet, on September 9 and 10 will be held in India’s national capital New Delhi. Over 25 world leaders along with other delegates are going to attend this mega event.
One of the largest multilateral summits, the G20 Summit presents a significant diplomatic opportunity for India, which will convene with the adoption of a joint declaration by all the member states/
India assumed the G20 Presidency on December 1 last year. The 18th G20 Summit in New Delhi is scheduled to be held on September 9-10. ……
The Group of Twenty (G20) comprises 19 countries …. and the European Union. The G20 members represent around 85% of the global GDP, over 75% of the global trade, and about two-thirds of the world population.
World leaders from several countries and institutions will mark their presence at the event. They include US President Joe Biden, UK Prime Minister Rishi Sunak, Australian Prime Minister Anthony Albanese, Canadian Prime Minister Justin Trudeau and French President Emmanuel Macron.
However, Russian President Vladimir Putin has opted out of the summit and foreign minister Sergei Lavrov will represent the country in his place. Chinese President Xi Jinping has also decided to skip the event and will send country’s Premier Li Qiang instead, according to sources.
The G20 Summit 2023 is being held under the theme – Vasudhaiva Kutumbakam (One Earth. One Family. One Future) – centered around the value of all life including human, animal, plant, and microorganisms and their interconnectedness on the planet Earth and in the wider universe.
India’s presidency of the summit holds significance as it aims to become a voice for the ‘less developed’ global South in a world dominated by developed nations of the West. It is also likely to take up the issue of border tension with China. India, for its part, may attempt to straighten out its diplomatic intricacies with the West after it faced challenges due to the Russia-Ukraine conflict. [Extracted, with edits and revisions, from “India gears up for G20 Summit: Check event venue, guest list, special invitees”, Hindustan Times]

Which of the following is incorrect? (Assuming H refers to Entropy in Information Theory)

The input to a matched filter is given by \( S(t) = 10 \sin(2\pi \times 10^6 t), 0<t<1 \) second. The peak amplitude of the filter output is (Note: The duration \(0<t<1\) second is very long for a 1 MHz signal. This implies many cycles. Energy of the signal will be large.)

Which of the following modulation scheme gives the maximum probability of error?

The number of bits per sample in a PCM system with sinusoidal input is increased from n to n+1. The improvement in signal to quantization noise ratio will be

In delta modulation (DM) system, the granular noise occurs when the modulating signal

Companding is used in PCM to

The main advantage of TDM over FDM is

The maximum permissible distance between two samples of a 2 kHz signal is