Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
Resistance of the galvanometer coil, G = 15 Ω
Current for which the galvanometer shows full scale deflection, Ig = 4 mA = 4 × 10−3 A
Range of the ammeter is 0, which needs to be converted to 6 A.
∴ Current, I = 6 A
A shunt resistor of resistance S is to be connected in parallel with the galvanometer to convert it into an ammeter. The value of S is given as:
S = `("I"_"g""G")/("I" - "I"_"g")`
= `(4 xx 10^-3 xx 15)/(6 - 4 xx 10^-3)`
S = `(6 xx 10^-2)/(6 - 0.004)`
= `0.06/5.996`
≈ 0.01 Ω = 10 mΩ
Hence, a 10 mΩ shunt resistor is to be connected in parallel with the galvanometer.
APPEARS IN
संबंधित प्रश्न
The combined resistance of a galvanometer of resistance 500Ω and its shunt is 21Ω. Calculate the value of shunt.
Show that the current flowing through a moving coil galvanometer is directly proportional to the angle of deflection of coil.
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
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.
- A circular coil of 30 turns and radius 8.0 cm carrying a current of 6.0 A is suspended vertically in a uniform horizontal magnetic field of magnitude 1.0 T. The field lines make an angle of 60° with the normal of the coil. Calculate the magnitude of the counter torque that must be applied to prevent the coil from turning.
- Would your answer change, if the circular coil in (a) were replaced by a planar coil of some irregular shape that encloses the same area? (All other particulars are also unaltered.)
With the help of a neat and labelled diagram, explain the principle and working of a moving coil galvanometer ?
Write current sensitivity of a galvanomete S.I. unit.
State the principle of the working of a moving coil galvanometer, giving its labeled diagram ?
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.
State how a moving coil galvanometer can be converted into an ammeter.
Explain the significance of a radial magnetic field when a current-carrying coil is kept in it.
The deflection in a moving coil galvanometer is ______.
The conversion of a moving coil galvanometer into a voltmeter is done by ______.
The coil of a moving coil galvanometer is wound over a metal frame in order to ______.
The current sensitivity of a galvanometer increase by 20%. If its resistance also increases by 25%, the voltage sensitivity will ______.
The coil of galvanometer consists of 100 turns and effective area of 1 square cm. The restoring couple is 10-8 N-m/rad. The magnetic field between the pole pieces is 5T. The current sensitivity of this galvanometer will be ______.
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 ______.
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?
