61801. Which of the following instruments is used almost exclusively to measure radio frequency currents?
61802. The coil of a DArsonval galvanometer has N turns. If flux density is B, current is I and area of coil is A, the deflecting torque is
61803. Consider the following statements regarding electromagnetic flowmeter AC excitation is used to avoid polarisation of fluid.The meter calibration is changed as viscosity of fluid changes.Stainless steel pipes can be used for measuring the flow of liquid of high conductivity. Of the above statements
61804. In a CRO, the time base signal is applied to
61805. Schering bridge operates at a high voltage of about 10 kV.
61806. Which of these instrument does not have a control spring?
61807. In Weston frequency meter, the magnetic axes of the two fixed coils are
61808. A 4-ohm resistor is connected across a 12 V battery.The current flowing will be
61809. Pirani gauge is used to measure
61810. Assertion (A): CRT is the most important component of a CRO.Reason (R): When an electron beam strikes the screen of CRT, a spot of light is produced.
61811. A capacitance transducer has two plates each of area 5 mm2. The coil gap is 2 mm. Displacement sensitivity due to change in gap length is
61812. Four capacitors are in parallel. Their values are 36.3 μF, 3.85 μF, 34.002 μF and 850 μF with an uncertainty of digit in the last place. The total capacitance in significant figures is
61813. In figure, C0 is distributed capacitance and C is tuning capacitor. If C = C1 for fundamental frequency and C = C2 for second harmonic, then C0 =
61814. If M is mutual inductance between fixed and moving coils and θ is deflection of dynamometer instrument, then
61815. The switch board instruments
61816. Radiation pyrometer is used to measure temperature in the range of
61817. The electromagnets of an induction wattmeter
61818. In a vibrating reed frequency meter the natural frequency of two adjacent reeds have a difference of
61819. Assertion (A): CRO can be used to study waveshape accurately.Reason (R): Input impedance of a CRO is very high.
61820. LVDT is used to measure
61821. The scale of PMMC instrument is linear.
61822. Assertion (A): Thermistors are commonly used to measure hot spot temperatures in electric machines.Reason (R): Thermistor has the advantages of high temperature coefficient, small size and high speed of response.
61823. Absolute instruments are used in
61824. Burden of an instrument transformer is expressed in
61825. Which of the following devices should be used for accurate measurement of a low dc voltage?
61826. If σ is standard deviation, variation is
61827. An electrodynamometer instrument has the advantage of
61828. The dimensions of permittivity are
61829. A Q meter uses the principle of
61830. In semiconductor strain gauge
61831. Four terminal approach is used in measuring low resistance because it
61832. In Weston synchronoscope the fixed coils are connected across
61833. Which of the following is not a transducer in true sense?
61834. It is required to measure a low magnitude high frequency current. The proper instrument is
61835. Bridge circuits using RTD in temperature measurement usually employ 3 lead system so as to obtain
61836. The stator of phase shifting transformer for use in conjunction with an ac potentiometer has a
61837. An average responding voltmeter using full wave rectifier has been calibrated to read 1 V for 1 V rms sinusoidal input. For 1 V peak to peak square wave input, the meter reading will be
61838. The sensitivity of a potentiometer can be increased by
61839. Two resistances are R1 = 36 ± 5% and R2 = 75 ± 5%. If they are connected in parallel, the limiting error in percent will be
61840. An ac bridge uses galvanometer as detector.
61841. In figure, the reading of wattmeter will be proportional
61842. Consider the following statements about mutual inductances: The value should remain constant under all conditions.The mutual inductance should not vary with temperature.The inductance should be independent of excitation.They have two coils wound on a bobbin of hard magnetic material, coils being separated by a range. Out of the above, correct statement are
61843. In low power factor wattmeter, the pressure coil is connected
61844. Figure shows the equivalent circuit of resistor. The resistor is non-inductive when
61845. The signal to noise ratio in telemetry should be better than
61846. Assertion (A): Electrodynamic instrument is not used as ammeter or voltmeter.Reason (R): Electrodynamic instrument is more costly than PMMC and moving iron instrument.
61847. Consider the following statements regarding electro-dynamometer type indicating instrument
It can be used for measuring Direct currentAlternating currentDirect voltageAlternating voltage Of these statements