GATE IN 2014 Question Paper (02-Feb-2014) (Shift 2)

A transit time ultrasonic flowmeter uses a pair of ultrasonic transducers placed at 45° angle, as shown in the figure.



The inner diameter of the pipe is 0.5 m. The differential transit time is directly measured using a clock of frequency 5 MHz. The velocity of the fluid is small compared to the velocity of sound in the static fluid, which is 1500 m/s and the size of the crystals is negligible compared to the diameter of the pipe. The minimum change in fluid velocity (m/s) that can be measured using this system is ___________.

Assuming on ideal op-amp in Linear range of operation, the magnitude of the transfer impedance $\frac{V_0}{i}$ in kΩ of the current to voltage converter shown in the figure is

For the circuit shown in the figure, the transistor has β = 40, V${}_{BE}$ = 0.7 V, and the voltage across the Zener diode is 15 V. The current (in mA) through the Zener diode is ________

In the figure, transistors T₁ and T₂ have identical characteristics with β = 100. V${}_{CE(Sat)}$ of transistor T₃ is 0.1 V. The voltage V₁ is high enough to put T${}_{3\text{­}}$ in saturation. Voltage V${}_{BE}$ of transistors. T₁, T₂ and T₃ is 0.7 V. The value of (V₁ – V₂) in V is ___________.

The figures show an oscillator circuit having an ideal Schmitt trigger and its input-output characteristics. The time period (in ms) of V₀(t) is _______.