Physics - Current Electricity - Quiz-10

A potentiometer circuit has been setup for finding the internal resistance of a given cell. The main battery, used across the potentiometer wire, has an emf of 2.0 V and a negligible internal resistance. The potentiometer wire itself is 4 m long. When the resistance, R, connected across the given cell, has values of
(i)infinity
(ii)9.5Ω
the 'balancing lengths', on the potentiometer wire are found to be 3m and 2.85m, respectively. The value of internal resistance of the cell is

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0.25Ω
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0.95Ω
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0.5Ω
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0.75Ω

A wire of resistance 4Ω is stretched to twice its original length. The resistance of a stretched wire would be :

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2Ω
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4Ω
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8Ω
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16Ω

The internal resistance of a 2.1V cell which gives a current of 0.2A through a resistance of 10Ω is :

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0.2Ω
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0.5Ω
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0.8Ω
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1.0Ω

The resistances of the four arms P, Q,R and S in a Wheatstone's bridge are 10Ω ,30Ω ,30Ω and 90Ω, respectively. The emf and internal resistance of the cell are 7 V and 5 Ω respectively. If the galvanometer resistance is 50Ω, the current drawn from the cell will be

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(1) 0A
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(2) 0.2A
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(3) 0.1A
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(4) 2.0A

In the circuit shown the cells A and B have negligible resistances. For $V_{A} = 12 V, R_{1} = 500 Ω a n d R = 100 Ω$ the galvanometer (g) shown no deflection.The value of $V_{B}$ is

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()4V
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()2V
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()12V
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()6V

If voltage across a bulb rated 220 V-100 W drops by 2.5% of its rated value, the percentage of the rated value by which the power would decrease is

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20%
0%

2.5%
0%

5%
0%

10%

A ring is made of a wire having a resistane

$R_{0} = 12 Ω$ . Find the points A and B, as shown

in the figure, at which a current carrying

conductor should be connected so that the

resistance R of the sub circuit between these

points is equal to 8/3 $Ω$

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$\frac{l_{1}}{l_{2}} = \frac{5}{8}$
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$\frac{l_{1}}{l_{2}} = \frac{1}{3}$
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$\frac{l_{1}}{l_{2}} = \frac{3}{8}$
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$\frac{l_{1}}{l_{2}} = \frac{1}{2}$

The power dissipated in the circuit shown in

the figure is 30 Watt. The value of R is :

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$20 Ω$
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$15 Ω$
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$10 Ω$
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$30 Ω$

A cell having an emf $ε$ internal resistance r

is connected across a variable external

resistance R. As the resistance R is increased,

the plot of potential difference V across R is given

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()
0%

()
0%

()
0%

()
0%

If power dissipated in the 9 $Ω$ resistor in the circuit

shown is 36 W, the potential difference across

the 2 $Ω$ resistor is

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() 8 V
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() 10 V
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() 2 V
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() 4 V

A current of 2A flows through a 2 $Ω$ resistor

when connected across a battery. The same

battery supplies a current of 0.5 A when

connected across a 9 $Ω$ resistor. The internal

resistance of the battery is

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$1 / 3 Ω$
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$1 / 4 Ω$
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$1 Ω$
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$0.5 Ω$

In the circuit in the figure, if the potential at point A is taken to be zero, the potential at point B is :

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-1V
0%
+2V
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-2V
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+1V

Which one of the following bonds produces a solid that reflects light in the visible region and whose electrical conductivity decreases with temperature and has high melting point?

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metallic bonding
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van der Waals'bonding
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ionic bonding
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covalent bonding

In the circuits shown below, the readings of the voltmeters and the ammeters will be:

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$V_{2} > V_{1} a n d i_{1} = i_{2}$
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$V_{2} = V_{1} a n d i_{1} > i_{2}$
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$V_{2} = V_{1} a n d i_{1} = i_{2}$
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$V_{2} > V_{1} a n d i_{1} > i_{2}$

Which of the following acts as a circuit protection device?

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Fuse
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Conductor
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Inductor
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Switch

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 1.0A when two way key is switched off. The balance points, when the key between the terminals (i) 1 and 2 (ii) 1and 3, is plugged in, are found to be at lengths $l_{1} c m a n d l_{2} c m$ respectively.The magnitudes, of the resistors R and X, in ohm, are then, equal, respectively, to

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() $k (l_{2} - l_{1}) a n d k l_{2}$
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() $k l_{1} a n d k (l_{2} - l_{1})$
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() $k (l_{2} - l_{1}) a n d k l_{1}$
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() $k l_{1} a n d k l_{2}$

Consider the following two statements :

Which of the following is correct?

(A) Kirchhoff's junction law follows from the conservation of charge.

(B) Kirchhoff's loop law follows from the conservation of energy.

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Both (A) and (B) are wrong
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(A) is correct and (B) is wrong
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(A) is wrong and (B) is correct
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Both (A) and (B) are correct

A wire of resistance $12 {Ωm}^{- 1}$ is bent to form a complete circle of radius 10 cm. The resistance between its two diametrically opposite points, A and B as shown in the figure, is :

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() $0.6 π Ω$
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() $3 Ω$
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() $6 π Ω$
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() $6 Ω$

A student measures the terminal potential difference (V) of a cell (of emf $ε$ and internal resistance r) as a function of the current (I) flowing through it. The slope and intercept of the graph between V and I, then respectively, equal :

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() $ε a n d ‐ r$
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() $‐ r a n d ε$
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() $r a n d ‐ ε$
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() $‐ ε a n d r$

A current of 3A flows through the 2 $Ω$ resistor shown in the circuit. The power dissipated in the $5 Ω$ resistor is

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() 4 W
0%
() 2 W
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() 1 W
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() 5 W

A wire of a certain material is streched slowly by ten per cent. Its new resistance and specific resistance become respectively

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(1) 2 times, 1.1 times
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(2) 1.21 times,same
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(3) both remain the same
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(4) 1.1 times, 1.1 times

An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature $20^{°}$ C? The temperature of boiling water is $100^{°}$ C

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() 6.3 min
0%

() 8.4 min
0%

() 12.6 min
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() 4.2 min

A cell can be balanced against 110cm and 100 cm of potentiometer wire, respectively with and without being short-circuited through a resistance of $10 Ω$ . Its internal resistance is

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(1) 0 $Ω$
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(2) 0.5 $Ω$
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(3) 2.0 $Ω$
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(4) zero

In the circuit shown, the current through the 4 $Ω$ resistor is 1 A when the points P and M are connected to a DC voltage source. The potential difference between the points M and N is

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1.5 V
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1.0 V
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4. 2 V
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3. 0.5 V

A capacitor of capacitance 5 μF is connected as shown in the figure. The internal resistance of the cell is 0.5 Ω. The amount of charge on the capacitor plate is?

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0 μC
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5 μC
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10 μC

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25 μC

In the circuit here, the steady state voltage across capacitor C is a fraction of the battery e.m.f. The fraction is decided by

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R₁ only

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R₁ and R₂ only

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R₁ and R₃ only

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R₁, R₂ and R₃

In the given figure each plate of capacitance C has partial value of charge?

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CE

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$\frac{C E R_{1}}{R_{2} - r}$

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$\frac{C E R_{2}}{R_{2} + r}$

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$\frac{C E R_{1}}{R_{1} - r}$

A 4 μF capacitor, a resistance of 2.5 MΩ is in series with 12 V battery. Find the time after which the potential difference across the capacitor is 3 times the potential difference across the resistor. [Given ln(2)= 0.693]

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13.86 s

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6.93 s

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7 s

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14 s

Three identical capacitors are given a charge Q each and they are then allowed to discharge through resistance R₁, R₂ and R₃. Their charges, as a function of time shown in the graph below. The smallest of the three resistance is

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R₃

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R₂

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R₁

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Cannot be predicted

Assertion : Electric conduction in gases is possible at normal pressure.
Reason : The electric conduction in gases depends only upon the potential difference between the electrodes.
If both the assertion and the reason are true and the reason is a correct explanation of the assertion
If both the assertion and reason are true but the reason is not a correct explanation of the assertion
If the assertion is true but the reason is false
If both the assertion and reason are false

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1

0%
2

0%
3

0%
4

0:0:1

0:0:1

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