IOCL Junior Operator Solved Questions & Answers || IOCL Junior Operator General Science Questions and Answers

• The recommended practice when measuring unknown voltage levels with a multimeter is to start with the highest range and work down.
• When measuring an unknown voltage, it’s best to start with the highest range on the multimeter.
• This prevents overloading the meter if the voltage is higher than expected.
• If the reading is low, you can then decrease the range to get a more precise measurement.
• Using a low range for a high voltage can damage the multimeter

• Electrical instruments can broadly be classified into absolute and secondary types.

Absolute Instruments: These instruments define the magnitude of an electrical quantity (like current, voltage, etc.) directly in terms of fundamental or base units (like mass, length, time). They don’t rely on comparison with another instrument. A tangent galvanometer is a classic example of Absolute Instruments.

Secondary Instruments: These instruments are calibrated against absolute instruments. They provide direct readings of the electrical quantity being measured. Voltmeters, ammeters, wattmeters, and energy meters are all examples of secondary instruments.

• Absolute Instruments gives the value of a quantity directly in terms of deflection and instrument constants.
• Absolute Instruments: These instruments define the magnitude of an electrical quantity (like current, voltage, etc.) directly in terms of fundamental or base units (like mass, length, time). They don’t rely on comparison with another instrument. A tangent galvanometer is a classic example of Absolute Instruments.
• Secondary Instruments: These instruments are calibrated against absolute instruments. They provide direct readings of the electrical quantity being measured. Voltmeters, ammeters, wattmeters, and energy meters are all examples of secondary instruments.

• Absolute instruments, like the tangent galvanometer, directly measure quantities using the instrument’s physical properties and fundamental units. They don’t need prior calibration.
• A tangent galvanometer is a classic example of an absolute instrument because the current is determined by the tangent of the deflection angle, the coil’s radius and number of turns, and the earth’s magnetic field.
• Other options (voltmeters, ammeters, wattmeters) are secondary instruments that do need calibrating.

• Secondary instruments (like voltmeters, ammeters) are practical, calibrated tools giving direct readings.
• Absolute instruments are mainly for calibration labs, not general commercial use.

• Secondary instruments are classified based on their Function.
• Secondary instruments are categorized by what they do, such as indicating (e.g., ammeter, voltmeter), recording (recording variations over time), or integrating (measuring total energy or quantity over a period)

• Indicating instruments, like analog voltmeters or ammeters, use a pointer and a calibrated scale (the dial) to show the value of the measured quantity immediately.
• Indicating instruments show the magnitude of an electrical quantity at the moment of measurement using a pointer moving on a calibrated scale or a digital display. They provide an immediate reading

• Indicating instruments display the instantaneous value of a measured quantity directly using a pointer on a scale.
• Ammeters, voltmeters, and wattmeters are common examples.
• Energy meters and Ampere-hour meters are integrating instruments, while recording voltmeters are recording instruments

• Integrating instruments measure and register the total quantity of electricity or energy consumed over a specific period.
• They provide a cumulative measurement rather than an instantaneous value.
• Examples include kilowatt-hour meters and ampere-hour meters

• Recording instruments use a pen (or similar marking device) to continuously trace the variations of an electrical quantity over time onto a moving graph paper.
• This creates a visual record of the measurement for later analysis