100-150

151. What is the purpose of a variable speed drive (VSD)? PHOTO

• A. To protect against overload.

• B. To reduce starting current peaks.

• C. To alter the motor speed by changing the frequency.

• D. To control the motor’s torque.

152. What is the primary function of a load-break switch? PHOTO

• A. To provide overload protection

• B. To make, carry, and break currents

• C. To protect against short circuits

• D. To operate as a manual disconnect switch

153. How does a fuse protect an electrical circuit? PHOTO

• A. By short-circuiting the circuit

• B. By increasing the circuit’s resistance

• C. By melting when too much current flows

• D. By regulating the voltage

154. What does an analog electronic signal represent?

• A. Digital information

• B. A constant voltage

• C. A voltage or current proportional to a measurement

• D. A binary code

155. What is the main advantage of using a loop calibrator for troubleshooting current loops?

• A. It is more accurate for measuring very small currents

• B. It is more affordable than other measurement tools

• C. It can both measure and source current in the loop.

• D. It is easier to use than a clamp-on milliammeter.

156. What is the main purpose of calibration for an instrument?

• A. To ensure accurate correspondence between input and output signals

• B. To improve the sensitivity of the instrument

• C. To diagnose any internal faults in the instrument.

• D. To adjust the instrument's range of measurement.

157. What does "ranging" an instrument involve?

• A. Adjusting the instrument's internal components for optimal performance

• B. Verifying the instrument's compliance with safety regulations.

• C. Setting the zero point of the measurement scale

• D. Defining the desired sensitivity to input changes

158. What is a common characteristic of both 3-15 PSI pneumatic and 4-20 mA current loop standards?

• A. They both use digital signals

• B. They both have a high voltage range

• C. They both can transmit data wirelessly

• D. They both use a live zero

159. What do the "zero" and "span" adjustments on a pressure transmitter allow you to do?

• A. Set the instrument for any desired range within its operational limits.

• B. Fine-tune the accuracy of the calibration at specific points

• C. Reset the instrument to its factory default settings.

• D. Compensate for drift in the instrument's performance over time.

160. How does a zero shift calibration error affect the instrument's response?

• A. It changes the slope of the response curve

• B. It shifts the entire response curve vertically.

• C. It introduces a non-linearity in the output signal

• D. It amplifies or attenuates the output signal strength.