239. A resistance strian guage with a guage factor of 3 is fastened to a steel member subjected to a stress of 100 N/mm2. The modulus of elasticity of steel is approximately 2 x 105 N / mm2. The percentage change in resistance is
240. Consider the following statements about LVDT as a transducer I. The relationship between input displacement and output voltage is almost linear 2. The range of displacement that can be measured is wide 3. It does not form a loading on the mechnical system. Of these stamtements
A. 1, 2 and 3 are correct
B. 2 and 3 are correct
C. 1 and 2 are correct
D. 1 and 3 are correct
241. An analog voltage signal whose highest significant is 1 kHz is to be digitally coded with a resolution of 0.01 % covering the voltage range of 0 to 10 volts. To avoid loss of information the MINIMUM number of bits in the digital code should be
242. The A to D converter used in a digital instrument could be I. successive approximation coverter type 2. flash converter type 3. dual slope converter type.The correct sequence of the increasing order of the conversion time taken by these types is
243. Which one of the follwing terms is NOT associated with a sample-and-hold circuit?
A. Conversion time
B. Acquisition time
C. Aperture time
D. Sample mode.
244. Two resistors R1 = 36 ohms and R2 = 75 ohms, each having tolerance of ? 5% are connected in series. The value of the resultant resistance will be
A. I 1 1 ? 0 ohm
B. 111 ?2.778 ohm
C. 1 1 1 ? 5.55 ohm
D. 111 ? 7.23 ohm
245. Wagner's earth devices are used in ac bridge circuits to
A. eliminate the effect of earth capacitance
B. eleminate the effect of inter-component capacitances
C. eliminate the effect of stray electrostatic fields.
D. shield the bridge elements.
Page 35 of 44