GATE IN 2017 Question Paper (12-Feb-2017) (Shift 2)

The magnetic flux density of an electromagnetic flowmeter is 100 mWb/m². The electrodes are wall-mounted inside the pipe having a diameter of 0.25 m. A voltage of 1 V is generated when a conducing fluid is passed through the flowmeter. The volumetric flowrate of the fluid in m³/s is _________.

The junction semiconductor temperature sensor shown in the figure is used to measure the temperature of hot air. The output voltage V${}_O$ is 2.1 V. The current output of the sensor is given by I = T μA where T is the temperature in K. Assuming the opamp to be ideal, the temperature of the hot air in °C is approximately _________.

Quantum efficiency of a photodiode (ratio between the number of liberated electrons and the number of incident photons) is 0.75 at 830 nm. Given Planck’s constant h = 6.624 × 10⁻³⁴ J-sec, the charge of an electron e = 1.6 × 10⁻¹⁹ C and the velocity of light in the photodiode C${}_m$ = 2 × 10⁸ m/s. For an incident optical power of 100 μW at 830 nm, the photocurrent in μA is __________.

In a sinusoidal amplitude modulation scheme (with carrier) the modulated signal is given by A${}_m$ (t) = 100 cos(ω${}_c$ t) + 50 cos(ω${}_m$ t) cos(ω${}_c$ t), where ω${}_c$ is the carrier frequency and ω${}_m$ is the modulation frequency. The power carried by the sidebands in % of total power is _________%.

An angle modulated signal with carrier frequency ω${}_c$ = 2π × 10⁶ rad/s given by ϕ${}_m$ (t) = cos(ω${}_c$ t + 5 sin (1000πt) + 10 sin (2000πt)). The maximum deviation of the frequency in the angle modulated signal from that of the carrier is ___________ kHz.