Current electricity questions with solutions

Showing 1–10 of 261 questions

• NumericmediumCurrent electricityElectrical Instruments: Galvanometer, Ammeter, Voltmeter & Potentiometer

  A galvanometer gives full-scale deflection at 0.006 A. With a 4990 Ω series resistance it becomes $a_0–30$ V voltmeter. If a resistance (2n/249) Ω is connected as a shunt, it becomes $a_0–1.5$ A ammeter. Find n.

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  JEE Advanced 2014

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• MCQeasyCurrent electricityElectric Current, Drift Velocity & Resistance

  The resistances of the platinum wire of a platinum resistance thermometer at the ice point and steam point are 8 Ω and 10 Ω respectively. After inserting in a hot bath of temperature 400°C, the resistance of platinum wire is:

  Options

  • Option A

    2 Ω

  • Option B

    16 Ω

  • Option C

    8 Ω

  • Option D

    10 Ω

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  JEE Mains 2024 04 Apr Morning Shift

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• NumericeasyCurrent electricityElectrical Instruments: Galvanometer, Ammeter, Voltmeter & Potentiometer

  In an experiment to find emf of a cell using a potentiometer, the null-point length for a cell of emf 1.5 V is 60 cm. If this cell is replaced by another cell of emf E, the null-point length increases by 40 cm. If E = x/10 V, the value of x is ______.

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  JEE Mains1 February 2023Shift 1Morning Shift

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• Multi-correctdifficultCurrent electricityElectrical Instruments: Galvanometer, Ammeter, Voltmeter & Potentiometer

  Three resistors R₁ = 3 kΩ, R₂ = 2 kΩ and R₃ = 5 kΩ have been connected to a constant current source as shown in the figure. The current source supplies current I = 2 mA to the circuit. A voltmeter with Rᵥ = 6 kΩ internal resistance is connected, as shown, to measure the potential difference across R₁.

  

  
  

  Select all that apply

  • Option A

    Percentage error = 25.9%

  • Option B

    Percentage error = 20.6%

  • Option C

    After interchanging R₂ and R₃, percentage error increases

  • Option D

    After interchanging R₂ and R₃, percentage error decreases

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  Current Electricity Objective Conversion

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• MCQmediumCurrent electricityCells, Maximum Power & Heating Effect

  In the circuit shown, the resistance r is a variable resistance. If for r = f R, the heat generation in r is maximum then the value of f is :

  

  Options

  • Option A

    1

  • Option B

    1/4

  • Option C

    1/2

  • Option D

    $\frac{3}{4}$

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  JEE Mains 2016

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• MCQeasyCurrent electricityCells, Maximum Power & Heating Effect

  When a potential difference V is applied across a wire of resistance R, it dissipates energy at a rate W. If the wire is cut into two halves and these halves are connected mutually parallel across the same supply, the same supply, the energy dissipation rate will become:

  Options

  • Option A

    1/4W

  • Option B

    1/2W

  • Option C

    2W

  • Option D

    4W

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  JEE Mains 2024 30 Jan Evening Shift

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• NumericmediumCurrent electricityElectrical Instruments: Galvanometer, Ammeter, Voltmeter & Potentiometer

  The coil of a calorimeter C has a resistance of R₁ = 60Ω. The coil R₁ is connected to the circuit as shown in figure. What is the rise in temperature (°C) of 240 grams of water poured into the calorimeter when it is heated for 7 minutes during which a current flow through the coil and the ammeter shows 3A? The resistance R₂ = 30Ω. [Disregard the resistances of the battery and the ammeter, and the heat losses and heat capacity of the calorimeter and the resistor and specific heat of water = 4200 J/kg°C]

  

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  JEE Advanced

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• Multi-correctmediumCurrent electricityElectrical Instruments: Galvanometer, Ammeter, Voltmeter & Potentiometer

  Consider two identical galvanometers and two identical resistors with resistance R. If the internal resistance of the galvanometers RC < R/2, which of the following statement(s) about any one of the galvanometers is(are) true?

  Select all that apply

  • Option A

    The maximum voltage range is obtained when all the components are connected in series.

  • Option B

    The maximum voltage range is obtained when the two resistors and one galvanometer are connected in series, and the second galvanometer is connected in parallel to the first galvanometer.

  • Option C

    The maximum current range is obtained when all the components are connected in parallel.

  • Option D

    The maximum current range is obtained when the two galvanometers are connected in series and the combination is connected in parallel with both the resistors.

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  JEE Advanced 2016

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• MCQmediumCurrent electricityCells, Maximum Power & Heating Effect

  The value of the resistance R in the circuit shown below so that electric bulb consumes the rated power is :-

  

  Options

  • Option A

    4 ohm

  • Option B

    6 ohm

  • Option C

    8 ohm

  • Option D

    10 ohm

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  JEE Advanced

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• IntegereasyCurrent electricityCells, Maximum Power & Heating Effect

  A potential V₀ is applied across a uniform wire of resistance R, giving power P₁. The wire is cut into two equal halves and V₀ is applied across each half separately. If P₂:P₁ = √x:1, find x.

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  JEE Mains13 April 2023Shift 1Morning Shift

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