JEE Questions for Physics Current Electricity I Quiz 8 - MCQExams.com

The resistance of a 5 cm long wire is 10 Ω. It is uniformly stretched so that its length becomes 20 cm.The resistance of the wire is
  • 160 Ω
  • 80 Ω
  • 40 Ω
  • 20 Ω
The resistance of an incandescent lamp is
  • Greater when switched off
  • Smaller when switched on
  • Greater when switched on
  • The same whether it is switched off or switched on
In the figure a carbon resistor has bands of different colours on its body as mentioned in the figure. The value of the resistance is
Physics-Current Electricity I-64945.png
  • 2.2 k Ω
  • 3.3 k Ω
  • 5.6 k Ω
  • 9.1 k Ω
By increasing the temperature, the specific resistance of a conductor and a semiconductor
  • Increases for both
  • Decreases for both
  • Increases, decreases
  • Decreases, increases

Physics-Current Electricity I-64947.png

  • Physics-Current Electricity I-64948.png
  • 2)
    Physics-Current Electricity I-64949.png
  • 2
  • 1
The drift velocity of free electrons in a conductor is v when a current i is flowing in it. If both the radius and current are doubled, then drift velocity will be

  • Physics-Current Electricity I-64951.png
  • 2)
    Physics-Current Electricity I-64952.png

  • Physics-Current Electricity I-64953.png

  • Physics-Current Electricity I-64954.png
Two wires of same material have length L and 2L and cross-sectional areas 4A and A respectively. The ratioof their specific resistances would be
  • 1 : 2
  • 8 : 1
  • 1 : 8
  • 1 : 1
When a current flows through a conductor itstemperature
  • May increase or decrease
  • Remains same
  • Decreases
  • Increases
A strip of copper and another of germanium are cooled from room temperature to 80 K. The resistance of
  • Each of these increases
  • Each of these decreases
  • Copper strip increases and that of germanium decreases
  • Copper strip decreases and that of germanium increases
The length of a given cylindrical wire is increased by 100 %. Due to the consequent decrease in diameter the change in the resistance of the wire will be
  • 300%
  • 200%
  • 100%
  • 50%
Express which of the following setups can be used toverify Ohm\'s law?

  • Physics-Current Electricity I-64958.png
  • 2)
    Physics-Current Electricity I-64959.png

  • Physics-Current Electricity I-64960.png

  • Physics-Current Electricity I-64961.png
The graph between resistivity and temperature, for a limited range of temperatures, is a straight line for amaterial like
  • Copper
  • Nichrome
  • Silicon
  • Mercury
  • Gallium arsenide
A steady current i is flowing through a conductor of uniform cross-section. Any segment of the conductor has
  • Zero charge
  • Only positive charge
  • Only negative charge
  • Charge proportional to current i
The density of copper is 9 × 103kg/m2and its atomicmass is 63.5u. Each copper atom provides one free electron. Estimate the number of free electrons percubic metre in copper
  • 1019
  • 1023
  • 1025
  • 1029
A thick wire is stretched so that its length becomes two times. Assuming that there is no change in its density, what is the ratio of change in resistance of wire to theinitial resistance of wire
  • 2 : 1
  • 4 : 1
  • 3 : 1
  • 1 : 4
What is the resistance of a carbon resistance which has bands of colours brown, black and brown?
  • 100 Ω
  • 1000 Ω
  • 10 Ω
  • 1 Ω
The lead wires should have
  • Larger diameter and low resistance
  • Smaller diameter and high resistance
  • Smaller diameter and low resistance
  • Larger diameter and high resistance
When a potential difference is applied across the ends of a linear metallic conductor
  • The free electrons are accelerated continuously from the lower potential end to the higher potential end of the conductor
  • The free electrons are accelerated continuously from the higher potential end to the lower potential end of the conductor
  • The free electrons acquire a constant drift velocity from the lower potential end to the higher potential end of the conductor
  • The free electrons are set in motion from their position of rest
A wire of diameter 0.02 metre contains 1028 free electrons per cubic metre. For an electrical current of 100 A, the drift velocity of the free electrons in the wireis nearly
  • 1 × 10–19 m/s
  • 5 × 10–10 m/s
  • 2 × 10–4 m/s
  • 8 × 103 m/s
The following four wires are made of the same material and are at the same temperature. Which one of them has highest electrical resistance?
  • Length = 50 cm, diameter = 0.5 mm
  • Length = 100 cm, diameter = 1 mm
  • Length = 200 cm, diameter = 2 mm
  • Length = 300 cm, diameter = 3 mm
Find the true statement
  • Ohm's law is applicable to all conductors of electricity
  • In an electrolyte solution, the electric current is mainly due to the movement of electrons
  • The resistance of an incandescent lamp is lesser when the lamp is switched on
  • The resistance of carbon decreases with the increase of temperature
The tolerance level of a resistor with the colour codered, blue, orange, gold is
  • ± 5%
  • ± 10%
  • ± 20%
  • ± 40%
If a wire is stretched to make it 0.1% longer, itsresistance will
  • Increase by 0.05%
  • Increase by 0.2%
  • Decrease by 0.2%
  • Decrease by 0.05%
In a conductor if 3000 coulomb of charge enters and 3000 coulomb of charge exits in time 10 minutes, thenthe current is
  • 5 ampere
  • 10 ampere
  • 2.5 ampere
  • Zero
The potential difference between points A and B ofadjoining figure is
Physics-Current Electricity I-64970.png

  • Physics-Current Electricity I-64971.png
  • 2)
    Physics-Current Electricity I-64972.png

  • Physics-Current Electricity I-64973.png
  • 2V
A wire of resistance R is divided in 10 equal parts. These parts are connected in parallel, the equivalent resistance of such connection will be
  • 0.01 R
  • 0.1 R
  • 10 R
  • 100 R
There are 8 equal resistances R. Two are connected in parallel, such four groups are connected in series, the total resistance of the system will be
  • R/2
  • 2R
  • 4 R
  • 8 R
The lowest resistance which can be obtained by connecting 10 resistors each of 1/10 ohm is
  • 1/250 Ω
  • 1/200 Ω
  • 1/100 Ω
  • 1/10 Ω
The reading of the ammeter as per figure shown is
Physics-Current Electricity I-64978.png

  • Physics-Current Electricity I-64979.png
  • 2)
    Physics-Current Electricity I-64980.png

  • Physics-Current Electricity I-64981.png

  • Physics-Current Electricity I-64982.png
Three resistors each of 2 ohm are connected together in a triangular shape. The resistance between any twovertices will be
  • 4/3 ohm
  • 3/4 ohm
  • 3 ohm
  • 6 ohm
Equivalent resistance between A and B will be
Physics-Current Electricity I-64985.png
  • 2 ohm
  • 18 ohm
  • 6 ohm
  • 3.6 ohm
How many minimum number of 2 Ω resistance can be connected to have an effective resistance of 1.5 Ω?
  • 3
  • 2
  • 6
  • 4
The effective resistance between the points A and B in the figure is
Physics-Current Electricity I-64988.png
  • 5 Ω
  • 2 Ω
  • 3 Ω
  • 4 Ω
Nine resistors each of 1 k Ω are connected to a battery of 6 V as shown in the circuit given below. What is thetotal current flowing in the circuit?
Physics-Current Electricity I-64990.png

  • Physics-Current Electricity I-64991.png
  • 2)
    Physics-Current Electricity I-64992.png

  • Physics-Current Electricity I-64993.png

  • Physics-Current Electricity I-64994.png
A current of 2 A flows in a system of conductors as shown. The potential difference (VA– VB) will be
Physics-Current Electricity I-64996.png
  • + 2 V
  • +1V
  • –1 V
  • –2V
The potential difference between A and B in the following figure is
Physics-Current Electricity I-64998.png
  • 24 V
  • 14 V
  • 32 V
  • 48 V
In the given circuit diagram the current through the battery and the charge on the capacitor respectively insteady state are
Physics-Current Electricity I-65000.png
  • 1 A and 3 μC
  • 11 A and 3μC

  • Physics-Current Electricity I-65001.png
  • 6 A and 0 μC
A metallic wire of resistance of 12 Ω is bent to form a square. The resistance between two diagonal pointswould be
  • 12 Ω
  • 24 Ω
  • 6 Ω
  • 3 Ω
The equivalent resistance of resistors connected in series is always
  • Equal to the mean of component resistors
  • Less than the lowest of component resistors
  • In between the lowest and the highest of component resistors
  • Equal to sum of component resistors
Figure shows a network of eight resistors, each equal to 2 Ω, connected to a 3V battery of negligible internal resistance. The current I in the circuit is
Physics-Current Electricity I-65005.png
  • 0.25 A
  • 0.50 A
  • 0.75 A
  • 1.0 A
If the ammeter in the given circuit reads 2 A, the resistance R is
Physics-Current Electricity I-65007.png
  • 1 ohm
  • 2 ohm
  • 3 ohm
  • 4 ohm
Two resistors are connected (a) in series (b) is parallel. The equivalent resistance in the two cases are 9 ohm and 2 ohm respectively. Then, the resistances of the component resistors are
  • 2 ohm and 7 Ω
  • 3 ohm and 6 Ω
  • 3 ohm and 9 Ω
  • 5 ohm and 4 Ω
Resistors of 1, 2, 3 ohm are connected in the form of a triangle. If a 1.5 volt cell of negligible internal resistance is connected across 3 ohm resistor, the current flowing through this resistance will be
  • 0.25 amp
  • 0.5 amp
  • 1.0 amp
  • 1.5 amp
Resistances of 6 ohm each are connected in the manner shown in adjoining figure. With the current 0.5 ampere as shown in figure, the potential difference VP–VQ is
Physics-Current Electricity I-65011.png
  • 3.6 V
  • 6.0 V P
  • 3.0 V 0.5 A
  • 7.2 V
The equivalent resistance of the arrangement of resistances shown in adjoining figure between thepoints A and B is
Physics-Current Electricity I-65013.png
  • 6 Ω
  • 8 Ω
  • 16 Ω
  • 24 Ω
In the network of resistors shown in the adjoining figure, the equivalent resistance between A and B is
Physics-Current Electricity I-65015.png
  • 54 ohm
  • 18 ohm
  • 36 ohm
  • 9 ohm
Four resistances are connected in a circuit in the given figure. The electric current flowing through 4 ohm and6 ohm resistance is respectively
Physics-Current Electricity I-65017.png
  • 2 amp and 4 amp
  • 1 amp and 2 amp
  • 1 amp and 1 amp
  • 2 amp and 2 amp
An infinite sequence of resistances is shown in the figure. The resultant resistance between A and B will be, when R1 =1 ohm and R2 = 2 ohm
Physics-Current Electricity I-65019.png
  • Infinity
  • 1 Ω
  • 2 Ω
  • 1.5 Ω
The equivalent resistance between points A and B with switch S open and closed are respectively
Physics-Current Electricity I-65021.png
  • 4 Ω, 8 Ω
  • 8 Ω, 4 Ω
  • 6 Ω, 9 Ω
  • 9 Ω, 6 Ω
In the figure shown, the total resistance between A and B is
Physics-Current Electricity I-65023.png
  • 12 Ω
  • 4Ω
  • 6Ω
  • 8Ω
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