JEE Questions for Physics Current Electricity I Quiz 21 - MCQExams.com

Variation of current passing through a conductor as the voltage applied across its ends is varied as shown in the adjoining diagram. If the resistance (R) is determined at the points A, B, C and D, we will find that
Physics-Current Electricity I-66186.png
  • RC = RD
  • RB> RA
  • RC> RB
  • None of these
From the graph between current I and voltage V shown below, identify the portion corresponding to negative resistance
Physics-Current Electricity I-66188.png
  • AB
  • BC
  • CD
  • DE
The resistance R1 of a conductor varies with temperature t as shown in the figure. If the variation is represented by Rt = R0 [1 + αt + βt2], then
  • α and β are both negative
  • α and β are both positive
  • α is positive and β is negative
  • α is negative and β is positive
A long straight wire of a circular cross-section (radius a) carries a steady current I and the current I is uniformly distributed across this cross-section. Which of the following plots represents the variation of magnitude of magnetic field B with distance r from the centre of the wire?

  • Physics-Current Electricity I-66190.png
  • 2)
    Physics-Current Electricity I-66191.png

  • Physics-Current Electricity I-66192.png

  • Physics-Current Electricity I-66193.png
The V–i graph for a conductor at temperatures T1 and T2are as shown in the figure. (T2– T1) is proportional to
Physics-Current Electricity I-66195.png
  • cos 2θ
  • sin θ
  • cot θ
  • tan θ
A battery consists of a variable number \'n\' of identical cells having internal resistances connected in series. The terminals of battery are short circuited and the current i is measured. Which of the graph below shows the relationship between i and n?

  • Physics-Current Electricity I-66203.png
  • 2)
    Physics-Current Electricity I-66204.png

  • Physics-Current Electricity I-66205.png

  • Physics-Current Electricity I-66206.png
In an experiment, a graph was plotted of the potential difference V between the terminals of a cell against the circuit current i by varying load rheostat. Internal conductance of the cell is given by
Physics-Current Electricity I-66208.png

  • Physics-Current Electricity I-66209.png
  • 2)
    Physics-Current Electricity I-66210.png

  • Physics-Current Electricity I-66211.png

  • Physics-Current Electricity I-66212.png
V–i graphs for parallel and series combination of two identical resistors are as shown in figure. Which graph represents parallel combination?
Physics-Current Electricity I-66214.png
  • A
  • B
  • A and B both
  • Neither A nor B
The ammeter has range 1 ampere without shunt. The range can be varied by using different shunt resistances. The graph between shunt resistance and range will have the nature
Physics-Current Electricity I-66216.png
  • P
  • Q
  • R
  • S
Assertion In a simple battery circuit the point of lowest potential is positive terminal of the battery
Reason The current flows towards the point of the higher potential as it flows in such a circuit from the negative to the positive terminal.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.

Physics-Current Electricity I-66217.png
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Assertion In meter bridge experiment, a high resistance is always connected in series with a galvanometer.
Reason As resistance increases current through the circuit increases.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Assertion Voltameter measures current more accurately than ammeter.
Reason Relative error will be small if measured from voltameter.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Assertion A potentiometer of longer length is used for accurate measurement.
Reason The potential gradient for a potentiometer of longer length with a given source of e.m.f. becomes small.
  • If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
  • If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.
  • If Assertion is true but Reason is false.
  • If the Assertion and Reason both are false.
  • If Assertion is false but Reason is true.
Figure shows a simple potentiometer circuit for measuring a small e.m.f. produced by a thermocouple. The meter wire PQ has a resistance 5 Ω and the driver cell has an e.m.f. of 2 V. If a balance point is obtained 0.600 m along PQ when measuring an e.m.f. of 6.00 mV, what is the value of resistance R?
Physics-Current Electricity I-66222.png
  • 995 Ω
  • 1995 Ω
  • 2995 Ω
  • None of these
A wire of resistance 5.5 Ω is drawn out uniformly so that its length is increased twice. Then its new resistance is
  • 44 Ω
  • 42 Ω
  • 40 Ω
  • 11 Ω
  • 22 Ω
In the circuit shown in figure, switch S1 is initially closed and S2 is open. Find Va–Vb
Physics-Current Electricity I-66228.png
  • 4 V
  • 8 V
  • 12 V
  • 16 V
The figure here shows a portion of a circuit. What are the magnitude and direction of the current i in the lower right-hand wire?
Physics-Current Electricity I-66230.png
  • 7 A
  • 8 A
  • 6 A
  • 2 A
A battery of 24 cells, each of e.m.f. 1.5 V and internal resistance 2 Ω is to be connected in order to send the maximum current through a 12 Ω resistor. The correct arrangement of cells will be
  • 2 rows of 12 cells connected in parallel
  • 3 rows of 8 cells connected in parallel
  • 4 rows of 6 cells connected in parallel
  • All of the above
A voltmeter of resistance 1000 Ω is connected across a resistance of 500 Ω in the given circuit. What will be the reading of voltmeter?
Physics-Current Electricity I-66233.png
  • 1 V
  • 2 V
  • 6 V
  • 4 V
A beam contains 2 × 108 doubly charged positive ionsper cubic centimeter, all of which are moving with a speed of 105 m/s. The current density is
  • 6.4 A/m2
  • 3.2 A/m2
  • 1.6 A/m2
  • None of these
In the circuit shown, the reading of ammeter when switch S is open and when switch S is closed respectively are
Physics-Current Electricity I-66236.png
  • 6 A and 7 A
  • 3 A and 4 A
  • 4 A and 5 A
  • 5 A and 6 A
In the circuit as shown in figure the
Physics-Current Electricity I-66238.png
  • Resistance R = 46 Ω
  • Current through 20 Ω resistance is 0.1 A
  • Potential difference across the middle resistance is 2V
  • All option are correct
Given figure shows a rectangular block with dimensions x, 2x and 4x. Electrical contacts can be made to the block between opposite pairs of faces (for example, between the faces labelled A-A, B-B and C-C). Between which two faces would the maximum electrical resistance be obtained (A-A : Top and bottom faces, B-B : Left and right faces, C-C : Front and rear faces)
Physics-Current Electricity I-66240.png
  • A-A
  • B-B
  • C-C
  • Same for all three pairs
A battery is connected to a uniform resistance wire AB and B is earthed. Which one of the graphs below shows how the current density J varies along AB?
Physics-Current Electricity I-66242.png

  • Physics-Current Electricity I-66243.png
  • 2)
    Physics-Current Electricity I-66244.png

  • Physics-Current Electricity I-66245.png

  • Physics-Current Electricity I-66246.png
A cylindrical metal wire of length l and cross sectional area S, has resistance R, conductance G,conductivity σ and resistivity ρ. Which one of the following expressions for σis valid?

  • Physics-Current Electricity I-66248.png
  • 2)
    Physics-Current Electricity I-66249.png

  • Physics-Current Electricity I-66250.png

  • Physics-Current Electricity I-66251.png
A potential divider is used to give outputs of 4 V and 8 V from a 12 V source. Which combination of resistances,(R1 : R2 : R3) gives the correct voltages ?
Physics-Current Electricity I-66253.png
  • 2 : 1 : 2
  • 1 : 1 : 1
  • 2 : 2 : 1
  • 1 : 1 : 2
Find equivalent resistance between A and B
Physics-Current Electricity I-66255.png
  • R
  • 2)
    Physics-Current Electricity I-66256.png

  • Physics-Current Electricity I-66257.png
  • 2R
Following figure shows four situations in which positive and negative charges move horizontally through a region and gives the rate at which each charge moves. Rank the situations according to the effective current through the region greatest first
Physics-Current Electricity I-66259.png
  • I = ii = iii = iv
  • I > ii > iii > iv
  • I = ii = iii > iv
  • I = ii = iii < iv
A and B are two square plates of same metal and same thickness but length of B is twice that of A. Ratio of resistances of A and B is
Physics-Current Electricity I-66261.png
  • 4 : 1
  • 1 : 4
  • 1 : 1
  • 1 : 2
A moving coil galvanometer is converted into an ammeter reading upto 0.03 A by connecting a shunt of resistance 4r across it and into an ammeter reading upto 0.06 A when a shunt of resistance r is connected across it. What is the maximum current which can be sent through this galvanometer if no shunt is used?
  • 0.01 A
  • 0.02 A
  • 0.03 A
  • 0.04 A
Two conductors are made of the same material and have the same length. Conductor A is a solid wire of diameter 1.0 mm. Conductor B is a hollow tube of outside diameter 2.0 mm and inside diameter 1.0 mm. The resistance ratio RA/RB will be
  • 1
  • 2
  • 3
  • 4
A wire has resistance of 24 Ω. is bent in the following shape. The effective resistance between A and B is
Physics-Current Electricity I-66265.png
  • 24 Ω
  • 10 Ω

  • Physics-Current Electricity I-66266.png
  • None of these
In the circuit shown in figure, find the current through the branch BD
Physics-Current Electricity I-66268.png
  • 5 A
  • 0 A
  • 3 A
  • 4 A
Two conductors have the same resistance at 0°C but their temperature coefficients of resistance are α1 and α2. The respective temperature coefficients of their series and parallel combinations are nearly

  • Physics-Current Electricity I-66270.png
  • 2)
    Physics-Current Electricity I-66271.png

  • Physics-Current Electricity I-66272.png

  • Physics-Current Electricity I-66273.png

Physics-Current Electricity I-66275.png

  • Physics-Current Electricity I-66276.png
  • 2)
    Physics-Current Electricity I-66277.png

  • Physics-Current Electricity I-66278.png

  • Physics-Current Electricity I-66279.png

  • Physics-Current Electricity I-66280.png
To verify Ohm's law, a student is provided with a test resistor RT , a high resistance R1, a small resistance R2 , two identical galvanometers G1 and G2 and a variable voltage source V. The correct circuit to carry out the experiment is

  • Physics-Current Electricity I-66282.png
  • 2)
    Physics-Current Electricity I-66283.png

  • Physics-Current Electricity I-66284.png

  • Physics-Current Electricity I-66285.png
Shown in the figure adjacent is a meter bridge set up with null deflection in the galvanometer. The value of the unknown resistor R is
Physics-Current Electricity I-66286.png
  • 13.75 Ω
  • 220 Ω
  • 110 Ω
  • 55 Ω
0:0:1


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