ISRO Scientist or Engineer Electronics Dec 2017
For the following questions answer them individually
The TWT is sometimes preferred to the magnetron as a radar transmitter output tube because it is
One of the reason why conventional vacuum valve tubes not used at microwave frequencies is that their
In a telecommunication trans-receive system, the transmitting antenna with antenna aperture of 1m is fed with 1W of power at 10GHz. The receive antenna with antenna aperture of 0.5m located at 1km away receives x mW of power. If the transmitting frequency changes to 20GHz, what will happen to receive power?
Find the maximum directivity of an antenna whose power density is given by $$W_{rad}= \hat{a} \frac{A_{o} \sin \theta}{r^{2}}$$ $$\frac{W}{m^{2}}$$ where $$A_{o}$$ is peak value of power density $$\theta$$ is the usual spherical coordinate and $$hat{ar}$$ is the radial unit vector
A DC series motor is driven by a chopper circuit. The supply voltage is 220 V and the duty cycle is 25%. Determine the DC voltage applied to the motor
A single-phase full-wave AC phase controller feeds power to a resistive load of 100 Ω from a 220 V, 50 Hz supply. What will be the R.M.S. output voltage at delay angles $$\alpha_{1}=\alpha_{2}=\alpha=\frac{\pi}{2}$$ of both transistors?
A half-wave rectifier is used to charge a 12 V battery through a resistance ‘R’. The input transformer is fed by 34 V AC with turns ratio 2:1. Calculate the conduction period of the diode.
Two signals $$f_{a}$$ and $$f_{b}$$ are given as input to EX-OR to measure phase difference. The average output voltage will be
From the following Relative amplitude vs Frequency plot, identify the type of noise which the sections A, B, C & D depict
(i) Thermal Noise (ii) Power line pick up
(iii) Power supply (EPC) switching noise (iv)1/f noise
