Advertisements
Advertisements
Question
An ideal voltmeter has _______.
(A) low resistance
(b) high resistance
(C) infinite resistance
(D) zero resistance
Advertisements
Solution
(c) Infinite resistance
APPEARS IN
RELATED QUESTIONS
The combined resistance of a galvanometer of resistance 500Ω and its shunt is 21Ω. Calculate the value of shunt.
The combined resistance of a galvanometer of resistance 500Ω and its shunt is 21Ω. Calculate the value of shunt.
A rectangular coil of a moving coil galvanometer contains 50 turns each having area 12 cm2 . It is suspended in radial magnetic field 0.025 Wb/m2 by a fibre of twist constant 15 x10-10 Nm/degree. Calculate the sensitivity of the moving coil galvanometer.
Obtain the expression for current sensitivity of moving coil galvanometer.
A galvanometer of resistance G is converted into a voltmeter to measure upto V volts by connecting a resistance R1 in series with the coil. If a resistance R2 is connected in series with it, then it can measures upto V/2 volts. Find the resistance, in terms of R1 and R2, required to be connected to convert it into a voltmeter that can read upto 2 V. Also find the resistance G of the galvanometer in terms of R1 and R2
Why is it necessary to introduce a cylindrical soft iron core inside the coil of a galvanometer?
Two moving coil meters, M1 and M2 have the following particulars:
R1 = 10 Ω, N1 = 30,
A1 = 3.6 × 10–3 m2, B1 = 0.25 T
R2 = 14 Ω, N2 = 42,
A2 = 1.8 × 10–3 m2, B2 = 0.50 T
(The spring constants are identical for the two meters).
Determine the ratio of
- current sensitivity and
- voltage sensitivity of M2 and M1.
Explain how moving coil galvanometer is converted into a voltmeter. Derive the necessary formula.
A rectangular coil of a moving coil galvanometer contains 100 turns, each having area
15 cm2. It is suspended in the radial magnetic field 0.03 T. The twist constant of suspension
fibre is 15 x 10-10 N-m/degree. Calculate the sensitivity of the moving coil galvanometer.
The fraction of the total current passing through the galvanometer is ............ .
a) `S/(S+G)`
b) `G/(S+G)`
c) `(S+G)/G`
d) `(S+G)/S`
A moving coil galvanometer has a resistance of 25Ω and gives a full scale deflection for a current of 10mA. How will you convert it into a voltmeter having range 0 - 100 V?
A galvanometer has a resistance of 16Ω. It shows full scale deflection, when a current of 20 mA is passed through it. The only shunt resistance available is 0.06 which is not appropriate to convert a galvanometer into an ammeter. How much resistance should be connected in series with the coil of galvanometer, so that the range of ammeter is 8 A?
Can a galvanometer as such be used for measuring the current? Explain.
How will you convert a moving coil galvanometer into a voltmeter?
Define current sensitivity of a galvanometer.
Define the current sensitivity of a galvanometer ?
Write current sensitivity of a galvanomete S.I. unit.
Figure shows two circuits each having a galvanometer and a battery of 3V.
When the galvanometers in each arrangement do not show any deflection, obtain the ratio R1/R2.

Draw a labelled diagram of a moving coil galvanometer and explain its working. What is the function of radial magnetic field inside the coil?
In the meter bridge experiment, balance point was observed at J with AJ = l.
(i) The values of R and X were doubled and then interchanged. What would be the new position of balance point?
(ii) If the galvanometer and battery are interchanged at the balance position, how will the alance point get affected?

State the principle of the working of a moving coil galvanometer, giving its labeled diagram ?
Outline the necessary steps to convert a galvanometer of resistance RG into an ammeter of a given range ?
State the underlying principle of working of a moving coil galvanometer. Write two reasons why a galvanometer can not be used as such to measure current in a given circuit. Name any two factors on which the current sensitivity of a galvanometer depends.
What are the advantages of using soft iron as a core, instead of steel, in the coils of galvanometers?
A moving coil galvanometer has a coil of resistance 59 Ω. It shows a full-scale deflection for a current of 50 mA. How will you convert it to an ammeter having a range of 0 to 3A?
Explain the significance of a radial magnetic field when a current-carrying coil is kept in it.
A galvanometer coil has a resistance of 12 Ω and the metre shows full scale deflection for a current of 3 mA. How will you convert the metre into a voltmeter of range 0 to 18 V?
A galvanometer coil has a resistance of 15 Ω and the metre shows full scale deflection for a current of 4 mA. How will you convert the metre into an ammeter of range 0 to 6 A?
The deflection in a moving coil galvanometer is ______.
In a moving coil galvanometer the deflection (Φ) on the scale by a pointer attached to the spring is ______.
A moving coil galvanometer can be converted into an ammeter by ______.
Assertion (A): On Increasing the current sensitivity of a galvanometer by increasing the number of turns may not necessarily increase its voltage sensitivity.
Reason (R): The resistance of the coil of the galvanometer increases on increasing the number of turns.
Select the most appropriate answer from the options given below:
A multirange voltmeter can be constructed by using a galvanometer circuit as shown in figure. We want to construct a voltmeter that can measure 2V, 20V and 200V using a galvanometer of resistance 10Ω and that produces maximum deflection for current of 1 mA. Find R1, R2 and R3 that have to be used.

A multirange current meter can be constructed by using a galvanometer circuit as shown in figure. We want a current meter that can measure 10 mA, 100 mA and 1A using a galvanometer of resistance 10 Ω and that prduces maximum deflection for current of 1mA. Find S1, S2 and S3 that have to be used

A galvanometer having a resistance of 20 Ω and 30 Ω division on both sides has figure of merit 0.005 ampere/division. The resistance that should be connected in series such that it can be used as a voltmeter upto 15 volt, is ______.
A galvanometer shows full-scale deflection for current Ig. A resistance R1 is required to convert it into a voltmeter of range (0 - V) and a resistance R2 to convert it into a voltmeter of range (0 - 2V). Find the resistance of the galvanometer.
Explain in brief the basic construction of a moving-coil table galvanometer whit a neat labelled diagram.
A voltmeter has a range of 0 - 20 V and a resistance of 500 Q. Explain how can be used to measure voltages from 0 - 200 volt?
A moving coil galvanometer of resistance 55 Ω produces a full scale deflection for a current of 250 mA. How will you convert it into an ammeter with a range of 0 - 3A?
The figure below shows a circuit containing an ammeter A, a galvanometer G and a plug key K. When the key is closed:

A galvanometer of resistance 100 Ω gives a full-scale deflection for a potential difference of 200 mV.
- What must be the resistance connected to convert the galvanometer into an ammeter of the range 0-200 mA?
- Determine resistance of the ammeter.
