WorksheetsDEE10133 CHAPTER 1 : DC METER
Total questions: 15
Worksheet time: 21mins
Figure shows an internal resistance 100Ω and 5mA as a total current used in series ohmmeter with R1 = 300Ω, R2 = 200Ω and V = 9V. Hence, calculate the value of Rx.
(a)
Name this circuit
(a)
In moving coil instrument consists of 110 turns wound on a square former length 1cm and 1.5cm wide. The flux density in the air gap is 0.07T. Determine the deflecting torque on the coil when carrying a current of 13mA
30µNm
15µNm
20µNm
45µNm
Why the pointer oscillate?
Pointer torque
Controlling torque
Damping torque
Deflecting torque
Calculate the sensitivity of a 200mA meter movement which is to be used as a DC voltmeter.
(a)
Refer to the table, which meter that have less loading effect?
(a)
A PMMC instrument with a full scale deflection of 40μA and an internal resistance of 500Ω is used as a voltmeter. Determine the value of the multiplier resistance needed to measure a voltage range of 0-10V.
(a)
Choose the correct description for DC Voltmeter
A small value multiplier resistor is connected in parallel to a PMMC meter movement
A large value multiplier resistor is connected in parallel to a PMMC meter movement
A small value multiplier resistor is connected in series to a PMMC meter movement
A large value multiplier resistor is connected in series to a PMMC meter movement
To build a circuit for a double range DC ammeter, ______________ shunt resistors m,ust be connected in ____________ with the meter movement.
two, series
three, series
two, parallel
three, parallel
A PMMC instrument can be used as _________ by connecting it with a low resistance shunt.
Voltmeter
Galvanometer
Ammeter
Wattmeter
Calculate the value of the shunt resistance required to convert a 1mA meter movement, woth a 100Ω internal resistance into 0-10 mA ammeter.
(a)
Figure 2 below shows a series ohmmeter circuit with a battery of 1.5V and total resistance of R1, R2 and Rm are 25kΩ. Calculate IFSD if the unknown resistance, RX = 0Ω.
(a)
Figure 2 below shows a series ohmmeter circuit with a battery of 1.5V and total resistance of R1, R2 and Rm are 25kΩ. Calculate RX if the ohmmeter scale at 0.75 FSD.
(a)
___________ is the difference between the expected value of the variable and the measured value of the variable.
Relative error
Absolute error
Gross error
Systematic error
The shunt ohmmeter circuit uses a 5μA total current with an internal resistance of 500Ω. The value of the current limiting resistor, R1 is 4.5kΩ. Calculate Rx when current is 1/2 FSD.
0 ohm
500 ohm
166.67 ohm
1500 ohm
