61651. A polyphase wattmeter basically consists of two wattmeters. The moving system of two wattmeters
61652. The dead zone in a pyrometer is 0.125% of span. The calibration is 400°C to 1000°C. What temperature change might occur before it is detected.
61653. The dimensions of force are
61654. An amplifier has to amplify pulses of 1 H-s duration. The minimum bandwidth of amplifier must be
61655. A moving coil meter has a resistance of 50 ohms and a full scale deflection current of 20 mA. To convert it into a voltmeter of 0-100 V range, the series resistance should be
61656. In measuring a resistance by voltmeter-ammeter method, the voltmeter can be connected either across supply or across the resistance. If the resistance is low, the voltmeters should be connected
61657. Which of the following methods can be used to measure power in a single phase circuit without using wattmeter? One voltmeter, one ammeterTwo voltmeters, two ammeterThree voltmetersThree ammeters
61658. For measurement of surface temperature of solids the elements of RTD is usually in the shape of
61659. As per BIS, the number of accuracy classes of instrument is
61660. In most of instruments, the controlling torque is provided by
61661. A 0-200 V voltmeter has a sensitivity of 1 kΩ per volt. The resistance of voltmeter is
61662. DC ampere hour meter is an indicating instrument.
61663. The accuracy of measurement by ohmmeter is very good.
61664. Hay's bridge is suitable for inductances having low L/R ratio.
61665. Moving iron instrument can be used for ac only.
61666. In electronic voltmeters the measuring device is a
61667. An ammeter has a resistance of 50 ohms and a shunt of 0.01 Ω. The deflection is θ. If the shunt resistance is increased to 0.02 Ω, the deflection will be.
61668. The ac bridge in figure is balanced. Z1 = 100∠30°, Z2 = 150∠0°, Z3 = 250∠ - 40° Then Z4 =
61669. Assertion (A): If the resistance of shunt of an ammeter is increased, the range of ammeter is reduced.Reason (R): If the series resistance of a voltmeter is increased, the range of voltmeter is increased.
61670. Two sinusoidal signals of equal amplitude and frequency are applied to X and Y plate of CRO respectively. The observed Lissajous pattern is a straight line. The phase shift between signals is
61671. The scale of a dynamometer is linear when used as
61672. Three phase four wire induction energy meter is used to measure
61673. A 10 ohm resistor is connected across a 20v battery.Power consumed is:
61674. An induction wattmeter can be used for ac only.
61675. To measure a resistance of about 8 ohms we should use
61676. For measuring temperatures below 800°C with high accuracy, the best instrument is
61677. Panel instruments are generally mounted vertically.
61678. Assertion (A): Many instruments use eddy current damping.Reason (R): Eddy currents set up a magnetic flux which opposes the original movement which generates them.
61679. The torque in induction wattmeters due to
61680. During testing of an energy meter, the energy recorded by meter was 0.05 kWh and correct energy was found to be 0.09 kWh. The error and correction respectively are
61681. Two resistances are : R1 = 36 Ω ± 1.89 Ω and R2 = 75 Ω ± 3.75 Ω. The sum R1 + R2 along with limiting error is
61682. An instrument of accuracy class 1 can have an error equal to
61683. In bridge circuit of figure, equivalent resistance between A and B is
61684. Assertion (A): The scale a PMMC ammeter is linear.Reason (R): The deflecting torque of PMMC is proportional to current in the coil.
61685. Assertion (A): Moving iron instrument can be used on ac or dc.Reason (R): In a moving iron instrument deflecting torque is proportional to square of current.
61686. A land line telemetry system is suitable for distance upto
61687. Use of high permeability core in moving iron instrument helps in
61688. The resistance of series field winding is a low resistance.
61689. Assertion (A): Double Kelvin's bridge is used to measure low resistances.Reason (R): In low resistance, the contact and lead resistances are very important.
61690. Shaft encoder is used to measure
61691. Assertion (A): Hay's bridge in particularly suitable for measuring inductance having a comparatively low resistance.Reason (R): In Hay's bridge the value of frequency supply must be known.
61692. The device having highest photo sensitivity is
61693. Which of the following closely represents the resistance-temperature characteristics of thermistor?
61694. For use at 50 Hz the range of scale of vibrating reed frequency meter is
61695. Consider the following statements about a moving iron instrument It is an unpolarised instrument.It has permanent magnet.It has a fixed coil.It has two iron vanes. Of these statements
61696. The two pressure coils in a single phase power factor meter of turns
61697. Piezoelectric effect can be used to measure
61698. A current of 3.18 A is flowing through resistance of 35.68 Ω. The voltage drop across resistance to the appropriate number of significant figures is
61699. A current of 3.25 A is flowing through a resistance of 34.98 Ω. The voltage drop across resistance to the appropriate number of significant figures is
61700. The braking torque in single phase energy meter is proportional to speed of disc.