NEET Physics Wheatstone Bridge and Different Measuring Instruments MCQs Set A

Question. Why is the Wheatstone bridge better than the other methods of measuring resistances?
(a) It is a null method
(b) It has four resistor arms
(c) It is based on Kirchoff’s law
(d) It does not involve Ohm’s law

Answer: A

Question. In the experiment of potentiometer, at balance point, there is no current in the
(a) galvanometer circuit
(b) potentiometer circuit
(c) both main and galvanometer circuits
(d) main circuit

Answer: A

Question. Sensitivity of potentiometer can be increased by
(a) increasing the length of the potentiometer
(b) decreasing the length of the potentiometer wire
(c) None of these
(d) increasing the e.m.f of the cell

Answer: A

Question. For measuring voltage of any circuit, potentiometer is preferred to voltmeter because
(a) the potentiometer almost draws no current during measurement.
(b) range of the voltmeter is not as wide as that of the potentiometer
(c) calibration in the voltmeter is sometimes wrong
(d) the potentiometer is cheap and easy to handle

Answer: A

Question. In a wheatstone bridge in the battery and galvanometer are interchanged then the deflection in galvanometer will
(a) not change
(b) change in opposite direction
(c) none of these
(d) change in previous direction

Answer: A

Question. In meter bridge or Wheatstone bridge for measurement of resistance, the known and the unknown resistance are interchanged. The error so removed is
(a) end correction
(b) index error
(c) due to temperature effect
(d) random error

Answer: A

Question. Assertion : In meter bridge experiment, a high resistance is always connected in series with a galvanometer. Reason : As resistance increase current more accurately then ammeter.
(a) Assertion is correct, reason is incorrect
(b) Assertion is incorrect, reason is correct.
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. In a Wheatstone bridge all the four arms have equal resistance R. If the resistance of galvanometer arm is also R, the equivalent resistance of combination is
(a) R
(b) R/2
(c) R/4
(d) 2R

Answer: A

Question. Assertion : The e.m.f of the driver cell in the potentiometer experiment should be greater that the e.m.f of the cell to be determined. Reason : The fall of potential across the potentiometer wire should not be less than the e.m.f of the cell to be determined.
(a) Assertion is correct, reason is correct; reason is a correct explanation for assertion.
(b) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(c) Assertion is correct, reason is incorrect
(d) Assertion is incorrect, reason is correct

Answer: A

Question. If specific resistance of a potentiometer wire is 10–7Wm current flowing through it, is 0.1 amp and cross sectional area of wire is 10–6 m2, then potential gradient will be
(a) 10–2 volt/m
(b) 10–6 volt/m
(c) 10–4 volt/m
(d) 10–8 volt/m

Answer: A

Question. An electric bulb is rated 220 volt - 100 watt. The power consumed by it when operated on 110 volt will be
(a) 25 watt
(b) 50 watt
(c) 40 watt
(d) 75 watt

Answer: A

Question. A current of 2 A, passing through a conductor produces 80 J of heat in 10 seconds. The resistance of the conductor in ohm is
(a) 2
(b) 4
(c) 20
(d) 0.5

Answer: A