If in the experiment of Wheatstone's bridge, the positions of cells and galvanometer are interchanged, then balance points will
(1) Change
(2) Remain unchanged
(3) Depend on the internal resistance of cell and resistance of galvanometer
(4) None of these
Two cells when connected in series are balanced on 8m on a potentiometer. If the cells are connected with polarities of one of the cells reversed, they balance on 2m. The ratio of e.m.f.'s of the two cells is
(1) 3 : 5
(2) 5 : 3
(3) 3 : 4
(4) 4 : 3
A voltmeter has a resistance of G ohms and range V volts. The value of resistance used in series to convert it into a voltmeter of range nV volts is :
(1) nG
(2)
(3)
(4)
Which of the following statement is wrong:
(1) Voltmeter should have high resistance
(2) Ammeter should have low resistance
(3) Ammeter is placed in parallel across the conductor in a circuit
(4) Voltmeter is placed in parallel across the conductor in a circuit
In the diagram shown, the reading of voltmeter is 20 V and that of ammeter is 4 A. The value of R should be (consider given ammeter and voltmeter are not ideal) :
(1) Equal to 5 Ω
(2) Greater from 5 Ω
(3) Less than 5 Ω
(4) Greater or less than 5 Ω depends on the material of R
A moving coil galvanometer has a resistance of 50 Ωand gives full scale deflection for 10 mA. How could it be converted into an ammeter with a full scale deflection for 1A :
(1) 50/99 Ω in series
(2) 50/99 Ω in parallel
(3) 0.01 Ω in series
(4) 0.01 Ω in parallel
Which is a wrong statement :
(1) The Wheatstone bridge is most sensitive when all the four resistances are of the same order
(2) In a balanced Wheatstone bridge, interchanging the positions of galvanometer and cell affects the balance of the bridge
(3) Kirchhoff's first law (for currents meeting at a junction in an electric circuit) expresses the conservation of charge
(4) The rheostat can be used as a potential divider
\(AB\) is a wire of uniform resistance. The galvanometer \(G\) shows no current when the length \(AC= 20~\text{cm}\) and \(CB = 80~\text{cm}\). The resistance \(R\) is equal to:
1. \(2~\Omega\)
2. \(8~\Omega\)
3. \(20~\Omega\)
4. \(40~\Omega\)
The circuit shown here is used to compare the e.m.f. of two cells and . The null point is at C when the galvanometer is connected to E1. When the galvanometer is connected to E2, the null point will be
(1) To the left of C
(2) To the right of C
(3) At C itself
(4) Nowhere on AB
In the Wheatstone's bridge (shown in the figure below) \(X=Y\) and \(A>B\). The direction of the current between \(a\) and \(b\) will be:
1. | from \(a\) to \(b\). |
2. | from \(b\) to \(a\). |
3. | from \(b\) to \(a\) through \(c\). |
4. | from \(a\) to \(b\) through \(c\). |