ISRO Scientist or Engineer Electronics 2018

Determine the Voltage transfer characteristics of the following circuit comprising of Zener diodes having identical characteristics with Zener Breakdown voltage $$V_z$$ and Diode cut-in voltage $$V_T$$

Two resistances of values 2Ω and 4Ω made of different materials with temperature coefficients of resistance 3 ppm/$$^\circ C$$ and 6 ppm/$$^\circ C$$ respectively are connected in series. What is the temperature coefficient of resistance of the net resistance?

Which of the following semiconductor compound is not used in the construction of Light Emitting Diodes?

An LCtank circuit resonates at a frequency ‘$$f_r$$’. If the temperature coefficient of permittivity of the dielectric material used in the Capacitance is 6 ppm/$$^\circ C$$, then what is the temperature coefficient of frequency‘$$f_r$$’.

To avoid difficulties with strapping at high frequencies, the type of cavity structure used in the magnetron is,

The transmittime in the repeller space of a reflex klystron must be $$\left(n + \frac{3}{4}\right)$$ cycles to ensure that,

‘For a circuit givenin figure, switch Kis closed to position 1 at t = 0. After t = 1 TC (Time Constant), switch is moved to position 2. Find The Current I at 1TC(-) (just before one-time constant time) and 1TC(+) Gust after one-time constant time) respectively (assume $$\frac{1}{e} \cong 0.37$$)

For a network shown in figure, which of the following statement is true.

Pair of differrential equations that describes motion of planet about sun using first two laws of Kepler is given as:

Two communication antennas A and B, one operating at 300 MHz and other at 3 GHz respectively and having same gain, are illuminated with identical flux density of -100 dBW/m$$^2$$. What is the relation between the received powers $$(P_A : P_B)$$?