Electrical And Electronic Measurement MCQs

When testing a coil having a ressistance of 10 ohms, resonance occured when the oscillator frequency was 10 MHz and the rotating capacitor was set at 500 / 271 pF. The effective value of the Q of the coil is

A 50 Hz voltage is measured with a moving iron voltmeter and a rectifier type ac voltmeter connected in parallel. If the meter readings are V1 and V2 respectively and the meters are free from calibration errors, then the form factor of the ac voltage may be estimated as

Consider the following statements regarding the causes of error in current transformers 1. Some exciting nunf is required by the primary winding to produce a flux 2. The flux density in the core is not a linear function of the magnetising force 3. There is some megnetic leakage in the secondary winding 4. There is significant power consumption in the metering current. Of these statements

The resistance of two coils of a wattmeter are 0-0.1 ohm and 1000 ohms respctively and both are noninductive. The load current is 20A and the voltage across the load is 30 V. In one of the two ways of connecting the voltage coil, the error in the reading would be

In the statement "the wattmeter commonly used for power measurement at commercial frequencies is of the 2i type. This meter consists of two coil systems, the fixed system being the X coil and moving system being coil". x, Y and Z stand respectively for

Two-wattmeter method is employed to measure power in a 3-phase balanced system with the current coils connected in the A and C lines. The phase sequence is ABC. If the wattmeter with its current coil in A-phase line reads zero, then the power factor of the 3-phase load will be

The shunt type ohmeter is NOT suitale for high resistance measurements because

A galvanometer is tested shown in figure, in the circuit where E = 1.5 V, 111 = 1.0 ohm, R2 = 2500 ohm and R3 is variable. With R3 set at 450 ohm, the galvanometer deflection is 140 mm and with R3 set at 950 ohm, the galvanometer deflection is 70 mm. The resistance of the galvanometer is

The measurement of very low and very high frequences is invariably done using a frequency counter / timer in the