UP polytechnic Lecturer (EE) Quiz 29

The sensitivity of a PMMC instrument is 20 kΩ/V. If this instrument is used in a rectifier type voltmeter with full wave rectification, the sensitivity will be

A 0-150 V voltmeter has a guaranteed accuracy of 1% of full scale reading. The voltage measured by this instrument is 75 V. What is the percentage of limiting error?

A moving coil instrument gives full-scale deflection with 15mAand has a resistance of 5Ω, The value of resistance to be connected in series to enable it to read up to 100 V is

Consider the following statements related to Hall effect:

1. Hall effect is used to determine whether a semiconductor is n -type or p-type.

2. To find the carrier concentration.

3. Measuring the conductivity (σ), the mobility (μ) can be calculated.

4. The Hall effect has been incorporated into a magnetic field meter.

Which of the above statements are correct?

In series type ohmmeter, full scale deflection current indicator is marked.

A 20-conductor coil shown in figure turned for 90° deflection while carrying 3. Find the electromagnetic torque experience by the coil when it is placed in a time invariant magnetic flux density of 1 mT.

The disc in the energy meter should be __________ for eddy current damping.

In wein’s bridge the formula for frequency f is