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question_answer1)
In an electrical cable there is a single wire of radius 9 mm of copper. Its resistance is \[5\,\Omega \]. The cable is replaced by 6 different insulated copper wires, the radius of each wire is \[3\,mm\]. Now the total resistance of the cable will be [CPMT 1988]
A)
\[7.5\,\Omega \] done
clear
B)
\[45\,\Omega \] done
clear
C)
\[90\,\Omega \] done
clear
D)
\[270\,\Omega \] done
clear
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question_answer2)
Two uniform wires \[A\] and \[B\] are of the same metal and have equal masses. The radius of wire \[A\] is twice that of wire \[B\]. The total resistance of A and \[B\] when connected in parallel is [MNR 1994]
A)
\[4\,\Omega \] when the resistance of wire \[A\] is \[4.25\,\Omega \] done
clear
B)
\[5\,\Omega \] when the resistance of wire \[A\] is \[4.25\,\Omega \] done
clear
C)
\[4\,\Omega \] when the resistance of wire \[B\] is \[4.25\,\Omega \] done
clear
D)
\[4\,\Omega \] when the resistance of wire \[B\] is \[4.25\,\Omega \] done
clear
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question_answer3)
Twelve wires of equal length and same cross-section are connected in the form of a cube. If the resistance of each of the wires is \[R\], then the effective resistance between the two diagonal ends would be [J & K CET 2004]
A)
2\[R\] done
clear
B)
12\[R\] done
clear
C)
\[\frac{5}{6}R\] done
clear
D)
8\[R\] done
clear
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question_answer4)
You are given several identical resistances each of value \[R=10\,\Omega \] and each capable of carrying maximum current of 1 ampere. It is required to make a suitable combination of these resistances to produce a resistance of \[5\,\Omega \] which can carry a current of 4 amperes. The minimum number of resistances of the type \[R\] that will be required for this job [CBSE PMT 1990]
A)
4 done
clear
B)
10 done
clear
C)
8 done
clear
D)
20 done
clear
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question_answer5)
The resistance of a wire is \[{{10}^{-6}}\Omega \] per metre. It is bend in the form of a circle of diameter \[2\,m\]. A wire of the same material is connected across its diameter. The total resistance across its diameter AB will be
A)
\[\frac{4}{3}\pi \times {{10}^{-6}}\Omega \] done
clear
B)
\[\frac{2}{3}\pi \times {{10}^{-6}}\Omega \] done
clear
C)
\[0.88\times {{10}^{-6}}\Omega \] done
clear
D)
\[14\pi \times {{10}^{-6}}\Omega \] done
clear
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question_answer6)
In the figure shown, the capacity of the condenser C is \[2\,\mu F\]. The current in \[2\,\Omega \] resistor is [IIT 1982]
A)
9 A done
clear
B)
0.9 A done
clear
C)
\[\frac{1}{9}A\] done
clear
D)
\[\frac{1}{0.9}A\] done
clear
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question_answer7)
When the key K is pressed at time \[t=0\], which of the following statements about the current I in the resistor AB of the given circuit is true [CBSE PMT 1995]
A)
I = 2 mA at all t done
clear
B)
I oscillates between 1 mA and 2mA done
clear
C)
I = 1 mA at all t done
clear
D)
At t = 0 , I = 2 mA and with time it goes to 1 mA done
clear
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question_answer8)
A torch bulb rated as 4.5 W, 1.5 V is connected as shown in the figure. The e.m.f. of the cell needed to make the bulb glow at full intensity is [MP PMT 1999]
A)
4.5 V done
clear
B)
1.5 V done
clear
C)
2.67 V done
clear
D)
13.5 V done
clear
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question_answer9)
In the circuit shown in the figure, the current through [IIT 1998]
A)
The 3W resistor is 0.50A done
clear
B)
The 3W resistor is \[0.25\,A\] done
clear
C)
The 4W resistor is 0.50A done
clear
D)
The 4W resistor is \[0.25\,A\] done
clear
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question_answer10)
There are three resistance coils of equal resistance. The maximum number of resistances you can obtain by connecting them in any manner you choose, being free to use any number of the coils in any way is [ISM Dhanbad 1994]
A)
3 done
clear
B)
4 done
clear
C)
6 done
clear
D)
5 done
clear
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question_answer11)
In the circuit shown, the value of each resistance is r, then equivalent resistance of circuit between points A and B will be [Similar to CBSE PMT 1999; RPET 1999]
A)
(4/3) r done
clear
B)
3r / 2 done
clear
C)
r / 3 done
clear
D)
8r / 7 done
clear
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question_answer12)
If in the circuit shown below, the internal resistance of the battery is 1.5 W and VP and VQ are the potentials at P and Q respectively, what is the potential difference between the points P and Q [MP PET 2000]
A)
Zero done
clear
B)
4 volts (VP > VQ) done
clear
C)
4 volts (VQ > VP) done
clear
D)
2.5 volts (VQ > VP) done
clear
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question_answer13)
Two wires of resistance R1 and R2 have temperature coefficient of resistance \[{{\alpha }_{1}}\text{ and }{{\alpha }_{2}}\], respectively. These are joined in series. The effective temperature coefficient of resistance is [MP PET 2003]
A)
\[\frac{{{\alpha }_{1}}+{{\alpha }_{2}}}{2}\] done
clear
B)
\[\sqrt{{{\alpha }_{1}}{{\alpha }_{2}}}\] done
clear
C)
\[\frac{{{\alpha }_{1}}{{R}_{1}}+{{\alpha }_{2}}{{R}_{2}}}{{{R}_{1}}+{{R}_{2}}}\] done
clear
D)
\[\frac{\sqrt{{{R}_{1}}{{R}_{2}}{{\alpha }_{1}}{{\alpha }_{2}}}}{\sqrt{R_{1}^{2}+R_{2}^{2}}}\] done
clear
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question_answer14)
Two cells of equal e.m.f. and of internal resistances \[{{r}_{1}}\] and \[{{r}_{2}}({{r}_{1}}>{{r}_{2}})\] are connected in series. On connecting this combination to an external resistance R, it is observed that the potential difference across the first cell becomes zero. The value of R will be [MP PET 1985; KCET 2005; Kerala PMT 2005]
A)
\[{{r}_{1}}+{{r}_{2}}\] done
clear
B)
\[{{r}_{1}}-{{r}_{2}}\] done
clear
C)
\[\frac{{{r}_{1}}+{{r}_{2}}}{2}\] done
clear
D)
\[\frac{{{r}_{1}}-{{r}_{2}}}{2}\] done
clear
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question_answer15)
When connected across the terminals of a cell, a voltmeter measures 5V and a connected ammeter measures 10 A of current. A resistance of 2 ohms is connected across the terminals of the cell. The current flowing through this resistance will be [MP PMT 1997]
A)
2.5 A done
clear
B)
2.0 A done
clear
C)
5.0 A done
clear
D)
7.5 A done
clear
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question_answer16)
In the circuit shown here, E1 = E2 = E3 = 2 V and R1 = R2 = 4 ohms. The current flowing between points A and B through battery E2 is [MP PET 2001]
A)
Zero done
clear
B)
2 amp from A to B done
clear
C)
2 amp from B to A done
clear
D)
None of the above done
clear
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question_answer17)
In the circuit shown below E1 = 4.0 V, R1= 2 W, E2 = 6.0 V, R2 = 4 W and R3 = 2 W. The current I1 is [MP PET 2003]
A)
1.6 A done
clear
B)
1.8 A done
clear
C)
1.25 A done
clear
D)
1.0 A done
clear
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question_answer18)
A microammeter has a resistance of \[100\,\Omega \] and full scale range of \[50\,\mu A\]. It can be used as a voltmeter or as a higher range ammeter provided a resistance is added to it. Pick the correct range and resistance combination [SCRA 1996; AMU (Med.) 2001; Roorkee 2000]
A)
50 V range with \[10\,k\Omega \] resistance in series done
clear
B)
10 V range with \[200\,k\Omega \] resistance in series done
clear
C)
10 mA range with \[1\,\Omega \] resistance in parallel done
clear
D)
10 mA range with \[0.1\,\Omega \] resistance in parallel done
clear
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question_answer19)
The potential difference across 8 ohm resistance is 48 volt as shown in the figure. The value of potential difference across X and Y points will be [MP PET 1996]
A)
160 volt done
clear
B)
128 volt done
clear
C)
80 volt done
clear
D)
62 volt done
clear
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question_answer20)
Two resistances \[{{R}_{1}}\] and \[{{R}_{2}}\] are made of different materials. The temperature coefficient of the material of \[{{R}_{1}}\] is \[\alpha \] and of the material of \[{{R}_{2}}\] is \[-\beta \]. The resistance of the series combination of \[{{R}_{1}}\] and \[{{R}_{2}}\] will not change with temperature, if \[{{R}_{1}}/{{R}_{2}}\] equals [MP PMT 1997]
A)
\[\frac{\alpha }{\beta }\] done
clear
B)
\[\frac{\alpha +\beta }{\alpha -\beta }\] done
clear
C)
\[\frac{{{\alpha }^{2}}+{{\beta }^{2}}}{\alpha \beta }\] done
clear
D)
\[\frac{\beta }{\alpha }\] done
clear
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question_answer21)
An ionization chamber with parallel conducting plates as anode and cathode has \[5\times {{10}^{7}}\] electrons and the same number of singly-charged positive ions per\[c{{m}^{3}}\]. The electrons are moving at 0.4 m/s. The current density from anode to cathode is \[4\,\mu A/{{m}^{2}}\]. The velocity of positive ions moving towards cathode is [CBSE PMT 1992]
A)
0.4 m/s done
clear
B)
16 m/s done
clear
C)
Zero done
clear
D)
0.1 m/s done
clear
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question_answer22)
A wire of resistance 10 W is bent to form a circle. P and Q are points on the circumference of the circle dividing it into a quadrant and are connected to a Battery of 3 V and internal resistance 1 W as shown in the figure. The currents in the two parts of the circle are [Roorkee 1999]
A)
\[\frac{6}{23}A\,\,\text{and}\,\text{ }\frac{18}{23}A\] done
clear
B)
\[\frac{5}{26}A\,\,\text{and}\,\frac{15}{26}A\] done
clear
C)
\[\frac{4}{25}A\,\,\text{and}\,\text{ }\frac{12}{25}A\] done
clear
D)
\[\frac{3}{25}A\,\,\text{and}\,\text{ }\frac{9}{25}A\] done
clear
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question_answer23)
In the given circuit, it is observed that the current I is independent of the value of the resistance R6. Then the resistance values must satisfy [IIT-JEE (Screening) 2001]
A)
\[{{R}_{1}}{{R}_{2}}{{R}_{5}}={{R}_{3}}{{R}_{4}}{{R}_{6}}\] done
clear
B)
\[\frac{1}{{{R}_{5}}}+\frac{1}{{{R}_{6}}}\]\[=\frac{1}{{{R}_{1}}+{{R}_{2}}}+\frac{1}{{{R}_{3}}+{{R}_{4}}}\] done
clear
C)
\[{{R}_{1}}{{R}_{4}}={{R}_{2}}{{R}_{3}}\] done
clear
D)
\[{{R}_{1}}{{R}_{3}}={{R}_{2}}{{R}_{4}}={{R}_{5}}{{R}_{6}}\] done
clear
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question_answer24)
In the given circuit, with steady current, the potential drop across the capacitor must be [IIT-JEE (Screening) 2001]
A)
V done
clear
B)
V / 2 done
clear
C)
V / 3 done
clear
D)
2V / 3 done
clear
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question_answer25)
A wire of length L and 3 identical cells of negligible internal resistances are connected in series. Due to current, the temperature of the wire is raised by \[\Delta \]T in a time t. A number N of similar cells is now connected in series with a wire of the same material and cross?section but of length 2 L. The temperature of the wire is raised by the same amount \[\Delta \]T in the same time t. the value of N is [IIT-JEE (Screening) 2001]
A)
4 done
clear
B)
6 done
clear
C)
8 done
clear
D)
9 done
clear
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question_answer26)
What is the equivalent resistance between the points A and B of the network [AMU (Engg.) 2001]
A)
\[\frac{57}{7}\Omega \] done
clear
B)
8 W done
clear
C)
6 W done
clear
D)
\[\frac{57}{5}\Omega \] done
clear
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question_answer27)
The effective resistance between points P and Q of the electrical circuit shown in the figure is [IIT-JEE (Screening) 2002]
A)
\[2Rr/(R+r)\] done
clear
B)
\[8R\,(R+r)/(3R+r)\] done
clear
C)
\[2r+4R\] done
clear
D)
\[5R/2\,\,+\,2r\] done
clear
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question_answer28)
In the circuit element given here, if the potential at point B, VB = 0, then the potentials of A and D are given as [AMU (Med.) 2002]
A)
\[{{V}_{A}}=-1.5\,V,\,{{V}_{D}}=+2\,V\] done
clear
B)
\[{{V}_{A}}=+1.5\,V,\,{{V}_{D}}=+2\,V\] done
clear
C)
\[{{V}_{A}}=+1.5\,V,\,{{V}_{D}}=+0.5\,V\] done
clear
D)
\[{{V}_{A}}=+1.5\,V,\,{{V}_{D}}=-0.5\,V\] done
clear
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question_answer29)
The equivalent resistance between the points P and Q in the network given here is equal to (given \[r=\frac{3}{2}\Omega \]) [AMU (Med.) 2002]
A)
\[\frac{1}{2}\,\,\Omega \] done
clear
B)
1 W done
clear
C)
\[\frac{3}{2}\,\,\Omega \] done
clear
D)
2 W done
clear
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question_answer30)
The current in a conductor varies with time t as \[I=2t+3{{t}^{2}}\] where I is in ampere and t in seconds. Electric charge flowing through a section of the conductor during t = 2 sec to t = 3 sec is [Orissa JEE 2003]
A)
10 C done
clear
B)
24 C done
clear
C)
33 C done
clear
D)
44 C done
clear
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question_answer31)
A group of N cells whose emf varies directly with the internal resistance as per the equation EN = 1.5 rN are connected as shown in the figure below. The current I in the circuit is [KCET 2003]
A)
0.51 amp done
clear
B)
5.1 amp done
clear
C)
0.15 amp done
clear
D)
1.5 amp done
clear
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question_answer32)
In the shown arrangement of the experiment of the meter bridge if AC corresponding to null deflection of galvanometer is x, what would be its value if the radius of the wire AB is doubled [IIT-JEE (Screening) 2003]
A)
x done
clear
B)
x/4 done
clear
C)
4x done
clear
D)
2x done
clear
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question_answer33)
The resistance of a wire of iron is 10 ohms and temp. coefficient of resistivity is \[5\times {{10}^{-3}}/{}^\circ C\]. At \[20{}^\circ C\] it carries 30 milliamperes of current. Keeping constant potential difference between its ends, the temperature of the wire is raised to \[120{}^\circ C\]. The current in milliamperes that flows in the wire is [MP PMT 1994]
A)
20 done
clear
B)
15 done
clear
C)
10 done
clear
D)
40 done
clear
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question_answer34)
Seven resistances are connected as shown in the figure. The equivalent resistance between A and B is [MP PET 2000]
A)
3 W done
clear
B)
4 W done
clear
C)
4.5 W done
clear
D)
5 W done
clear
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question_answer35)
A battery of internal resistance 4W is connected to the network of resistances as shown. In order to give the maximum power to the network, the value of R (in \[\Omega \]) should be [IIT 1995]
A)
4/9 done
clear
B)
8/9 done
clear
C)
2 done
clear
D)
18 done
clear
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question_answer36)
In the circuit shown here, the readings of the ammeter and voltmeter are [Kerala PMT 2002]
A)
6 A, 60 V done
clear
B)
0.6 A, 6 V done
clear
C)
6/11 A, 60/11 V done
clear
D)
11/6 A, 11/60 V done
clear
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question_answer37)
Length of a hollow tube is 5m, it?s outer diameter is 10 cm and thickness of it?s wall is 5 mm. If resistivity of the material of the tube is 1.7 ´ 10?8 W´m then resistance of tube will be
A)
5.6 ´ 10?5 W done
clear
B)
2 ´ 10?5 W done
clear
C)
4 ´ 10?5 W done
clear
D)
None of these done
clear
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question_answer38)
A wire of resistor R is bent into a circular ring of radius r. Equivalent resistance between two points X and Y on its circumference, when angle XOY is a, can be given by
A)
\[\frac{R\alpha }{4{{\pi }^{2}}}(2\pi -\alpha )\] done
clear
B)
\[\frac{R}{2\pi }(2\pi -\alpha )\] done
clear
C)
R (2p ? a) done
clear
D)
\[\frac{4\pi }{R\alpha }(2\pi -\alpha )\] done
clear
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question_answer39)
Potential difference across the terminals of the battery shown in figure is (r = internal resistance of battery)
A)
8 V done
clear
B)
10 V done
clear
C)
6 V done
clear
D)
Zero done
clear
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question_answer40)
As the switch S is closed in the circuit shown in figure, current passed through it is
A)
4.5 A done
clear
B)
6.0 A done
clear
C)
3.0 A done
clear
D)
Zero done
clear
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question_answer41)
In the following circuit a 10 m long potentiometer wire with resistance 1.2 ohm/m, a resistance R1 and an accumulator of emf 2 V are connected in series. When the emf of thermocouple is 2.4 mV then the deflection in galvanometer is zero. The current supplied by the accumulator will be
A)
4 ´ 10?4 A done
clear
B)
8 ´ 10?4 A done
clear
C)
4 ´ 10?3 A done
clear
D)
8 ´ 10?3 A done
clear
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question_answer42)
In the following circuit, bulb rated as 1.5 V, 0.45 W. If bulbs glows with full intensity then what will be the equivalent resistance between X and Y
A)
0.45 W done
clear
B)
1 W done
clear
C)
3 W done
clear
D)
5 W done
clear
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question_answer43)
Consider the circuits shown in the figure. Both the circuits are taking same current from battery but current through R in the second circuit is \[\frac{1}{10}\]th of current through R in the first circuit. If R is 11 W, the value of R1
A)
9.9 W done
clear
B)
11 W done
clear
C)
8.8 W done
clear
D)
7.7 W done
clear
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question_answer44)
In order to quadruple the resistance of a uniform wire, a part of its length was uniformly stretched till the final length of the entire wire was 1.5 times the original length, the part of the wire was fraction equal to
A)
1 / 8 done
clear
B)
1 / 6 done
clear
C)
1 / 10 done
clear
D)
1 / 4 done
clear
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question_answer45)
In the circuit shown in figure reading of voltmeter is V1 when only S1 is closed, reading of voltmeter is V2 when only S2 is closed and reading of voltmeter is V3 when both S1 and S2 are closed. Then
A)
V3 > V2 > V1 done
clear
B)
V2 > V1 > V3 done
clear
C)
V3 > V1 > V2 done
clear
D)
V1 > V2 > V3 done
clear
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question_answer46)
Current through wire XY of circuit shown is
A)
1 A done
clear
B)
4 A done
clear
C)
2 A done
clear
D)
3 A done
clear
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question_answer47)
12 cells each having same emf are connected in series with some cells wrongly connected. The arrangement is connected in series with an ammeter and two cells which are in series. Current is 3 A when cells and battery aid each other and is 2 A when cells and battery oppose each other. The number of cells wrongly connected is
A)
4 done
clear
B)
1 done
clear
C)
3 done
clear
D)
2 done
clear
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question_answer48)
Following figure shows cross-sections through three long conductors of the same length and material, with square cross-section of edge lengths as shown. Conductor B will fit snugly within conductor A, and conductor C will fit snugly within conductor B. Relationship between their end to end resistance is
A)
RA = RB = RC done
clear
B)
RA > RB > RC done
clear
C)
RA < RB < R done
clear
D)
Information is not sufficient done
clear
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question_answer49)
In the following star circuit diagram (figure), the equivalent resistance between the points A and H will be
A)
1.944 r done
clear
B)
0.973 r done
clear
C)
0.486 r done
clear
D)
0.243 r done
clear
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question_answer50)
In the adjoining circuit diagram each resistance is of 10 W. The current in the arm AD will be
A)
\[\frac{2i}{5}\] done
clear
B)
\[\frac{3i}{5}\] done
clear
C)
\[\frac{4i}{5}\] done
clear
D)
\[\frac{i}{5}\] done
clear
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question_answer51)
In the circuit of adjoining figure the current through 12 W resister will be
A)
1 A done
clear
B)
\[\frac{1}{5}A\] done
clear
C)
\[\frac{2}{5}A\] done
clear
D)
0 A done
clear
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question_answer52)
The reading of the ideal voltmeter in the adjoining diagram will be
A)
4 V done
clear
B)
8 V done
clear
C)
12 V done
clear
D)
14 V done
clear
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question_answer53)
The resistance of the series combination of two resistance is S. When they are joined in parallel the total resistance is P. If S = nP, then the minimum possible value of n is [AIEEE 2004]
A)
4 done
clear
B)
3 done
clear
C)
2 done
clear
D)
1 done
clear
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question_answer54)
A moving coil galvanometer has 150 equal divisions. Its current sensitivity is 10 divisions per milliampere and voltage sensitivity is 2 divisions per millivolt. In order that each division reads 1 volt, the resistance in ohms needed to be connected in series with the coil will be [AIEEE 2005]
A)
99995 done
clear
B)
9995 done
clear
C)
\[{{10}^{3}}\] done
clear
D)
\[{{10}^{5}}\] done
clear
View Solution play_arrow