6 QA on Wheat stone bridge principle | Learn Physics

6 Question-Answer on Wheat stone bridge principle

1.       Why is the wheatstone bridge better than the other methods of measuring resistances?

(a)    It does not involve Ohm’s law

(b)   It is based on Kirchhoff’s law

(c)    It has four resistor arms

(d)   It is a null method.

Ans: (d)

2.       If the experiment of Wheatstone’s bridge, the position of cells and galvanometer are interchanged, then balance point will

(a)    Change

(b)   Remain unchanged

(c)    Depend on the internal resistance of cell and resistance of galvanometer

(d)   None of these

Ans: ( b)

3.       In Meter Bridge or wheatstone bridge for measurement of resistance, the known and the unknown resistances are interchanged. The error so removed is:

(a)    End correction

(b)   Index error

(c)    Due to temperature effect

(d)   Random error

Ans: (a)

4.       A, B, C and D are four resistances of 2,2,2 and 3 Ω respectively. They are used to form a Wheatstone bridge. The resistance D is short circuited with a resistance R in order to get the bridge balanced. The value of R will be?

(a)    4 Ω

(b)   6Ω

(c)    8Ω

(d)   3Ω

Ans: ( b)

5.       In a Wheatsotone bridge, P = 90Ω, Q = 110Ω, R = 40Ω and S= 60 Ω and a cell of 4 V e.m.f. Then the potential difference between B and D will be?

(a)    -0.2 V

(b)   + 0.2 V

(c)    – 1 V

(d)   +1 V

Ans: (a )

6.       Four resistances of 10Ω, 60Ω, 100Ω and 200Ω respectively taken in order are used to form a Wheatstone bridge. A 15 V battery is connected to the ends of a 200 Ω resistance, the current through it will be

(a)    7.5 × 10^-5 A

(b)   7.5 × 10^-4 A

(c)    7.5 × 10^-3 A

(d)   7.5 × 10^-2A

Ans: (d)