JEE Questions for Physics Current Electricity I Quiz 19 - MCQExams.com

A cell of internal resistance r is connected to an external resistance R. The current will be maximum in R, if
  • R = r
  • R < r
  • R > r
  • R = r/2
Two identical cells send the same current in 2 Ω, resistance, whether connected in series or in parallel. The internal resistance of the cell should be
  • 1 Ω
  • 2 Ω

  • Physics-Current Electricity I-66009.png
  • 2.5 Ω
The internal resistances of two cells shown are 0.1Ω and 0.3 Ω. If R = 0.2 Ω, the potential difference across the cell
Physics-Current Electricity I-66011.png
  • B will be zero
  • A will be zero
  • A and B will be 2V
  • A will be > 2V and B will be < 2V
The figure shows a network of currents. The magnitude of currents is shown here. The current i will be
Physics-Current Electricity I-66015.png
  • 3 A
  • 13 A
  • 23 A
  • –3 A
A battery of e.m.f. E and internal resistance r is connected to a variable resistor R as shown here. Which one of the following is true?
Physics-Current Electricity I-66016.png
  • Potential difference across the terminals of the battery is maximum when R = r
  • Power delivered to the resistor is maximum when R = r
  • Current in the circuit is maximum when R = r
  • Current in the circuit is maximum when R >> r
Two cells having the internal resistance 0.2 Ω. and 0.4 Ω are connected in parallel. The voltage across the battery terminal is 1.5 Volt. The e.m.f. of first cell is 1.2 Volt. The e.m.f. of the second cell is
  • 2.7 Volt
  • 2.1 Volt
  • 3 Volt
  • 4.2 Volt
The current in the arm CD of the circuit will be
Physics-Current Electricity I-66018.png
  • i1 + i2
  • i2+ i3
  • i1 + i3
  • i1–i2 + i3
If VAB = 4V in the given figure, then resistance X will be
Physics-Current Electricity I-66022.png
  • 5 Ω
  • 10 Ω
  • 15Ω
  • 20 Ω
The internal resistance of a cell of e.m.f. 12 V is 5 × 10–2Ω. It is connected across an unknown resistance. Voltage across the cell, when a current of 60 A is drawn from it, is
  • 15 V
  • 12 V
  • 9 V
  • 6 V
The current in the given circuit is
Physics-Current Electricity I-66026.png
  • 0.1 A
  • 0.2 A
  • 0.3 A
  • 0.4 A
The internal resistance of a cell is the resistance of
  • Electrodes of the cell
  • Vessel of the cell
  • Electrolyte used in the cell
  • Material used in the cell
How much work is required to carry a 6μC charge from the negative terminal to the positive terminal of a 9 V battery?
  • 54 × 10–3 J
  • 54 × 10–6 J
  • 54 × 10–9 J
  • 54 × 10–12 J
The e.m.f of a battery is 2 V and its internal resistance is 0.5 Ω. The maximum power which it can deliver to anyexternal circuit will be
  • 8 Watt
  • 4 Watt
  • 2 Watt
  • None of these
Kirchhoff\'s I law and II law of current, prove the
  • Conservation of charge and energy
  • Conservation of current and energy
  • Conservation of mass and charge
  • None of the above
Eels are able to generate current with biological cells called electroplaques. The electroplaques in an eel are arranged in 100 rows, each row stretching horizontally along the body of the fish containing 5000 electroplaques. The arrangement is suggestively shown below. Each electroplaque has an e.m.f. of 0.15 V and internal resistance of 0.25 Ω
The water surrounding the eel completes a circuit between the head and its tail. If the water surrounding it has a resistance of 500 Ω, the current an eel can produce in water is about
Physics-Current Electricity I-66031.png
  • 1.5 A
  • 3.0 A
  • 15 A
  • 30 A
Current provided by a battery is maximum when
  • Internal resistance equal to external resistance
  • Internal resistance is greater than external resistance
  • Internal resistance is less than external resistance
  • None of the above
A battery is charged at a potential of 15 V for 8 hours when the current flowing is 10 A. The battery on discharge supplies a current of 5 A for 15 hours. The mean terminal voltage during discharge is 14 V. The \ Watt-hour\ efficiency of the battery is
  • 82.5%
  • 80%
  • 90%
  • 87.5%
A capacitor is connected to a cell of e.m.f. E having some internal resistance r. The potential difference across the
  • Cell is < E
  • Cell is E
  • Capacitor is > E
  • Capacitor is < E
When the resistance of 9 Ω is connected at the ends of a battery, its potential difference decreases from 40 volt to 30 volt. The internal resistance of the battery is
  • 6 Ω
  • 3 Ω
  • 9 Ω
  • 15 Ω
Two batteries, one of e.m.f. 18 volt and internal resistance 2 Ω and the other of e.m.f. 12 volt and internal resistance 1 Ω, are connected as shown. The voltmeter V will record a reading of
Physics-Current Electricity I-66035.png
  • 15 volt
  • 30 volt
  • 14 volt
  • 18 volt
Two sources of equal e.m.f. are connected to an external resistance R. The internal resistances of the two sources are R1 and R2 (R2> R1). If the potential difference across the source having internal resistanceR2 is zero, then
  • R = R1 R2 / (R1 + R2)
  • R = R1R2 / (R2– R1)
  • R = R2× (R1 + R/ (R2– R1)
  • R = R1– R1
The magnitude of i in ampere unit is
Physics-Current Electricity I-66038.png
  • 0.1
  • 0.3
  • 0.6
  • None of the above
To draw maximum current from a combination of cells,how should the cells be grouped
  • Series
  • Parallel
  • Mixed
  • Depends upon the relative values of external and internal resistance
A current 2 A flows through a 2 Ω resistor when connected across a battery. The same battery supplies a current 0.5 A when connected across a 9 Ω resistor. The internal resistance of the battery is
  • 1 Ω
  • 0.5 Ω
  • 1/3 Ω
  • 1/4 Ω
In the circuit shown in the figure, if the potential at point A is taken to be zero, the potential at point B is
Physics-Current Electricity I-66041.png
  • –2 V
  • +1 V
  • –1 V
  • +2 V
A galvanometer can be converted into an ammeter byconnecting
  • Low resistance in series
  • High resistance in parallel
  • Low resistance in parallel
  • High resistance in series
A galvanometer having a coil resistance of 60 Ω shows full scale deflection when a current of 1.0 amp passes through it. It can be converted into an ammeter to readcurrents upto 5.0 amp by
  • Putting in parallel a resistance of 240 Ω
  • Putting in series a resistance of 15 Ω
  • Putting in series a resistance of 240 Ω
  • Putting in parallel a resistance of 15 Ω
In the circuit given, the correct relation to a balancedWheatstone bridge is
Physics-Current Electricity I-66044.png

  • Physics-Current Electricity I-66045.png
  • 2)
    Physics-Current Electricity I-66046.png

  • Physics-Current Electricity I-66047.png
  • None of these

Physics-Current Electricity I-66048.png
  • 3V
  • 2.25V
  • 4V
  • 4.5V
By ammeter, which of the following can be measured
  • Electric potential
  • Potential difference
  • Current
  • Resistance
The resistance of 1 A ammeter is 0.018 Ω. To convert it into 10 A ammeter, the shunt resistance required will be
  • 0.18 Ω
  • 0.0018 Ω
  • 0.002 Ω
  • 0.12 Ω
An ammeter of 5 ohm resistance can read 5 mA. If it is to be used to read 100 volt, how much resistance is to be connected in series?
  • 19.9995 Ω
  • 199.995 Ω
  • 1999.95 Ω
  • 19995 Ω
When a 12 Ω resistor is connected with a moving coil galvanometer then its deflection reduces from 50 divisions to 10 divisions. The resistance of the galvano-meter is
  • 24 Ω
  • 36 Ω
  • 48 Ω
  • 60 Ω
A galvanometer can be used as a voltmeter by connecting a
  • High resistance in series
  • Low resistance in series
  • High resistance in parallel
  • Low resistance in parallel
A battery of 6 volts is connected to the terminals of a three metre long wire of uniform thickness and resistance of the order of 100 Ω. The difference of potential between two points separated by 50 cm on the wire will be
  • 1 V
  • 1.5 V
  • 2 V
  • 3 V
A galvanometer of resistance 50 Ω is connected to a battery of 3V along with a resistance of 2950 Ω in series. A full scale deflection of 30 divisions is obtained in the galvanometer. In order to reduce this deflection to 20 divisions, the resistance in series should be
  • 6050 Ω
  • 4450 Ω
  • 5050 Ω
  • 5550 Ω
A cell can be balanced against 110 cm and 100 cm of potentiometer wire, respectively with and without being short circuited through a resistance of 10 Ω Its internal resistance is
  • 2.0 ohm
  • Zero
  • 1.0 ohm
  • 0.5 Ω
If the balance point is obtained at the 35th cm in a meter bridge, the resistances in the left and right gaps are in the ratio of
  • 7 : 13
  • 13 : 7
  • 9 : 11
  • 11 : 9
A cell in secondary circuit gives null deflection for 2.5 m length of potentiometer having 10 m length of wire. If the length of the potentiometer wire is increased by 1 m without changing the cell in the primary, the position of the null point now is
  • 3.5 m
  • 3 m
  • 2.75 m
  • 2.0 m
In a meter bridge experiment, resistances are connected as shown in figure. The balancing length l1 is 55 cm. Now an unknown resistance x is connected in series with P and the new balancing length is found tobe 75 cm. The value of x is
Physics-Current Electricity I-66058.png

  • Physics-Current Electricity I-66059.png
  • 2)
    Physics-Current Electricity I-66060.png

  • Physics-Current Electricity I-66061.png

  • Physics-Current Electricity I-66062.png

  • Physics-Current Electricity I-66063.png
A voltmeter has a resistance of G ohm and range V volt. The value of resistance used in series to convert itinto a voltmeter of range nV volt is

  • Physics-Current Electricity I-66065.png
  • 2)
    Physics-Current Electricity I-66066.png

  • Physics-Current Electricity I-66067.png

  • Physics-Current Electricity I-66068.png
A moving coil galvanometer has a resistance of 50 Ω and gives full scale deflection for 10 mA. How could it be converted into an ammeter with a full scaledeflection for 1A
  • 50/99 Ω in series
  • 50 / 99 Ω in parallel
  • 0.01 Ω in series
  • 0.01 Ω in parallel
A galvanometer of resistance 25 Ω giving full scale deflection for a current of 10 milliampere, is to be changed into a voltmeter of range 100 V by connecting a resistance of `13.\' in series with galvanometer. Thevalue of resistance R in Ω is
  • 10000
  • 10025
  • 975
  • 9975
The resistance of a galvanometer is 25 ohm and it requires 50μA for full deflection. The value of the shunt resistance required to convert it into an ammeter of 5 amp is
  • 2.5 × 10–4Ω
  • 1.25 × 10–3 ohm
  • 0.05 ohm
  • 2.5 ohm
In the Wheatstone\'s bridge (shown in figure) X = Y and A > B. The direction of the current between ab will be
Physics-Current Electricity I-66073.png
  • From a to b
  • From b to a
  • From b to a through c
  • From a to b through c

Physics-Current Electricity I-66075.png
  • The galvanometer shows a deflection when switch S is closed
  • The galvanometer shows a deflection when switch S is open
  • The galvanometer shows no change in deflection whether S is open or closed
  • The galvanometer shows no deflection
A resistance of 4 Ω and a wire of length 5 metres and resistance 5 Ω are joined in series and connected to a cell of e.m.f. 10 V and internal resistance 1 Ω. A parallel combination of two identical cells is balanced across 300 cm of the wire. The e.m.f. E of each cell is
Physics-Current Electricity I-66076.png
  • 1.5 V
  • 3.0 V
  • 0.67 V
  • 1.33 V
The resistivity of a potentiometer wire is 40 × 10–8ohm-m and its area of cross-section is 8 × 10–6m2. If 0.2 amp current is flowing through the wire, the potential gradient will be
  • 10–2 volt/m
  • 10–1 volt/m
  • 3.2 × 10–2 volt/m
  • 1 volt/m
A potentiometer circuit is set up as shown. The potential gradient, across the potentiometer wire, is k volt/cm and the ammeter, present in the circuit, reads 1.0 A when two way key is switched off. The balance points, when the key between the terminals (i) 1 and 2 (ii) 1 and 3, is plugged in, are found to be at lengths l1 cm and 12 cm respectively. The magnitudes, of theresistors R and X, in ohms, are then, equal, respectively,to
Physics-Current Electricity I-66079.png
  • kl1 and k12
  • k (l2–land kl2
  • kl1 and k(l2 – l1)
  • k (l2 –land kl1
A potentiometer consists of a wire of length 4 m and resistance 10 Ω. It is connected to a cell of e.m.f. 2 V. The potential difference per unit length of the wire will be
  • 0.5 V/m
  • 2 V/m
  • 5V/m
  • 10 V/m
0:0:1


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