Question

A piezo-electric transducer has a capacitance of $500pF$ and a charge senstivity of $25\times {10}^{-3}C/m.$ The connecting cable has a capacitance of $200pF$ while the oscilloscope used for readout has readout input resistance of $500k\Omega$ with a parallel capacitance of $25pF.$ The sensitivity of the transducer along is

• A. $34.4\times {10}^{6}V/m$
• B. $35.7\times {10}^{6}V/m$
• C. $40\times {10}^{6}V/m$
• D. $50\times {10}^{6}V/m$

Answer 1

The correct option is D $50\times {10}^{6}V/m$

$\text{Charge sensitivity of transducer,}$

$K_q=25\times {10}^{-3}C/m$

$\text{Capacitance of transducer}=500pF$

$\therefore \text{Sensitivity of transducer}$

$=\frac{K_q}{C_P}=\frac{25\times {10}^{-3}}{500\times {10}^{-12}}=50\times {10}^{6}V/m$