Current Electricity Questions and Answers

AB is a potentiometer wire of length 100 cm and its resistance is 10 ohm It is connected in series with a battery of emf 2V and resistance 40 ohm If a source of unknown emf E is balanced by 40 cm length of the potentiometer wire the value of E is R 400 2V H A ww 40 cm C 1 E Only one option is correct B 0 8 V

The network shown in figure is a part of a complete circle If at a certain instant the current 1 is 5 A and is ncreasing at a rate of 103 A s then value of VB VA and current in 2 2 resistance are respectively 15V A 10 43481 5 mH men B

85 The equivalent resistance of the circuit between points A and B is Ao Bo 1 2R 3 3R www 2r 2r www www 4r 4r www 8r www 2 1 2 R 4 1 3 R 00 89 85 The equivalent resistance of the circuit b

Figure shows a circuit containing three resistors X X2 X3 an ideal inductor an ideal capacitor and an ideal emf source connected as shown The resistors have resistance Reach the inductor has inductance L the capacitor has capacitance C and the emf source has emf Given R The switch is first connected to position 1 When charge on capacitor becomes half of its maximum possible value then switch S is connected to position 2 Current in resistance X3 just after shifting the switch from position 1 to position 2 is given L 5mH C 2 F R 1002 E 5V 5 1 R Xa R R X X

circuit is in unbalanced condition as potential difference is same across ends of wire Although mathematically i have found potential difference across ab in terms of i and that current will from b to a as Vb Va but sir as AB is a wire connected in between circuit so potential difference across its ends should be zero and no current should flow through it theoretically pls explain that A foor m Mu 52 502 Nor

An electric kettle takes 4A current at 220V How much time will it take to boil 1kg of water from temperature 20 C The temperature of boiling water is 100 C Question Type Single Correct Type 1 2 3 4 12 6 min 4 2 min 6 3 min 8 4 min

n be image We have to find the total resistance of it The answer to this is that in this circuit sho rt circuit will happen please give a detailed solution of this quest ion diagram give This question is of higher level than class10 Voltage of battery is a volt y AM R 12 Rg d R 2L R 1 R ID R 12 R10

If the potential difference V applied across a conductor is increased to 2V with its temperature kept constant free electrons in a conductor i remain the same ii become half of its previous value iii be double of its initial value iv become zero

The resistances of the four arms P Q R and S in a Wheatstone s bridge are 10 ohm 30 ohm 30 ohm and 90 ohm respectively The e m f and internal resistance of the cell are 7 volt and 5 ohm respectively If the galvanometer resistance is 50 ohm the current drawn from the cell will be NEET 2013 1 0 2 A 2 0 1 A 3 2 0 A

6 When some potential difference is maintained between A and B current I enters the network at A and leaves at B When switch S is closed the equivalent resistance between A and B is ohm 20 92 5Q A I S I B

Question 4 Viow In English v In the given figure each plate of capacitance C has partial value of charge Options 1 O CE CER 2 O R r CER 3 R r R wwww R

A potentiometer consists of a wire of length 10 m and resistance 30 Q is connected in series with a battery of e m f 2 5 V and internal resistance 5 Q with external resistance R Q If the fall of potential along the potentiometer wire is 50 HV then value of R in ohm mm is 80 115 100 50

An electron moves in a circle of radius 1 0 m with a constant speed of 4 0 x 106 m s The current at a point on the circle is approximately O 1 0 10 11 A 1 0 10 2 A 1 0 10 13 A 1 0 x 10 10 A

A battery of e m f 2 0 V and internal resistance 0 5 is connected across a resistance of 9 52 The number of electrons flowing through the cross section of resistance per second is 1 25 1018 1 25 1017 2 5 1018 O 2 5 x 1017

Two coils have self inductances L 4 mH and L 8 mH Current in both the coils is increasing at same rate At an instant when power given to the two coils is same find ratio of currents in the inductors L and L2

In the circuit shown in figure below the cells and E have e m f 4 V and 8 V and internal resistance 0 5 ohm and 1 0 ohm respectively Then potential difference across cell E and E will be E 8 V 0 592 www 4 V www 4 592 30 ww 622 3 75 V 7 5 V O 4 25 V 7 5 V 4 25 V 4 25 V 5 0 V 7 0 V 19 WWW

Magnetic flux linked with a stationary loop of resistance R varies with time t as at T t Amount of heat generated in loop during time interval Tis aT O at 3R O a T 3R O O a T R a T 3R

In the circuit shown in figure each resistance is of 7 and internal resistance of cell is 1 2 The reading of ideal ammeter A is 14 V 122 2 A 4 A 8 A 6 A www www www www A www www www

4 j nqva in the direction of current flow A non conducting ring of radius R has two positive point charges lying diametrically opposite to each other each of magnitude Q The ring rotates with an angular velocity oo If I is the equivalent current then 1 IQoo Qo 200 T 2 I 41 de daar i 1 I Qo 3 in our faufta fergan va s af finn 0 Qu 2000 H 2 1 3 4 1 3

4 Intensity of bulb A remains same and intensity of bulb B decreases 0 A conductor of area of cross section A having 40 charge carriers each having a charge q is subjected to a potential V The number density of charge carriers in the conductor is n and the charge carriers are moving with average velocity V A current I flows in the conductor If is the current density then 1 nqV in the direction of current flow to 4 Al 3417 Ted vai a i 1 3 jnqV in the direction perpendio questionpape nqV 2 nqv in the direction opposite to current t current flow 4 jnqv in the direction of current flow I wanted t n E 4 nov f a V faya y er 2 ve fayda a fen 3 Va 9

The value of steady current in 2 resistance shown in figure is 2 F HH 3 0 A O 1 2 A 202 www 0 9 A 392 www 492 www 6 0 V 2 892 www

The equivalent resistance between points A and D of the combination of resistances shown in figure is 10 Q 1092 www A C 10 Q2 W 2092 B WWW 10 92 30 2 352 20 22 Read More www ww 1092 20 22 www 1092 D

In the circuit shown in figure potential difference between points A and B VA VB is A 5922 www 502 www 592 O 2 V 1 5 V 1 25 V O 1 75 V Yh 2 V www 522 0 592 www www 5 V B www 502

In the circuit shown the heat produced in 20 resistance is 10 cal s then heat produced in 10 resistor is A 222 ww 20 cal s 50 cal s 100 cal s Read More 200 cal s 322 www 10 Q2 www 15 Q ww B

In the circuit shown in Figure the current through 1998S 2 Ma a b c d 9V 30 802 202 www 22 202 the 32 resistor is 0 50 A the 3 2 resistor is 0 25 A the 4 resistor is 0 50 A the 4 Q resistor is 0 25 A 80 20 www 22 40

the circuit below the time What is the current in the 302 resistor the moment immediately after the switch is opened The capacitor in the figure has capacitance of 9F 00 O 1 3 A O 2 3 A O 0 5 A 01 A 9V O 0 33 A 62 WWW S WH 352 65

1 10 2 20V 3 30V 4 15V In the combination shown in figure find the charge on the 4 F capacitor 1 30 C 3 24 C HH 13 F 41 se 1 IA Common Test 5 36 10V 1 F HH HE SUF 2 2 5 C 4 10 C 3 30V 20 fuff and t 1 30 C 3 24 C fery WHE HH HH 3pF 4 ISV 10V HH 5 F 2 2 5 C 4 10 C 1001CMD302120 Hindi 07102

1 3A www 302 9V Find reading of ammeter in given circuit 2 6A 4 4 5A 3 1 5A www 352 at Course Il 151 www 302 www 302 9V 1 3A 3 1 5A ww 100 www 302 2 6A 4 4 5A ER 1001CMDY

How can we determine the Thevenin resistance O Shorting all voltage sources O Opening all current sources O Shorting all voltage sources and opening all current sources O Opening all voltage sources and shorting all current sources

0 In the circuit shown the power developed in 40 the 652 resistor is 6W The power developed in the 4 resistor is 1 16 W 3 6 W usiest Course li H 30092020 652 2 9 W 4 4 W 40 1 16 W 3 6 W Space for Rough Work ard for 606 W st 2 9W

28 The resultant resistance of n wires each of 28 resistance r ohms is R when they are connected in parallel When these n resistances are connected in series the resultant resistance will be 1 R n 3 R 4 n R afe 3 fe 3 R 4 n R

1 1 2 2 1 4 3 4 1 4 2 1 Three 60W 120V light bulbs are connected 39 across a 120 V power source If resistance of each bulb does not change with current then find out total power delivered to the three bulbs 120V 1 180 W 2 20 W In the circuit shown 3 40 W 4 60 W the power developed in 40 1 1 2 2 1 4 3 4 1 4 2 1 60W 120 Vangen 120 V er et af a falda din a 120V 1 180 W 2 20 W 3 40 W 4 60 W nequestion paper

ALLEN A voltmeter of resistance 100002 gives full scale 33 deflection when a current of 100 mA flow through it The shunt resistance required across it to enable it to be used as an ammeter reading 1 A at full scale deflection is 1 10000 2 3 222 2 A galvanometer has a resistance of 36630 A 34 2 9000 2 4 1110 10000 a 100 mA qui a fait M 1 10000 2 3 222 02 f 2 9000 Q 4 1110 ada 36630

In the circuit shown in figure 50 www 40 30 ALLEN 41 40V 1 Power supplied by battery is 200W 2 Current in wire AB is zero 3 Potential difference across 502 resistance is same as potential difference across 302 resistance 4 Current flowing in circuit is 5A A 3 volt battery with negligible internal 42 faangen afrua feen v 1 2 AB 3 5 3 40 az A B 30 40V 200 and a t 4 SA RI fark

In the circuit of adjoining figure the current through 1202 resister will be 1 1 A 3 2 5 E A 502 5V 10022 1202 wwww 552 5V H A 4 0 A Telegram ne question 1 1A 3 A 120 13 E 5V 1002 1202 www 2 552 5V 4 0 A F

a Liquid oxygen at 50K is heated to 300K at constant pressure of 1 atm The rate of heating is constant Which one of the following graphs represents the variation of temperature with time c Time 2 Time KR d Time 170 Time From NCERT NEET 201

In the circuit of adjoining figure the current 32 through 1202 resister will be 1 1 A 2 502 www SV ww 1202 3 SQ F ZA 4 0 A The currant in racistance R in the given circuit ram ne questionpaper je 22 AE 120 Perf www 1202 1 1A 2 A 3 A 502 CF A 4 0 A

6 For a cell terminal P D is 2 2V when circuit is 26 open and reduces to 1 8V when cell is connected to a resistance of R 502 Determine internal resistance of cell r 1 2 3 2 2 fall 1 8V fat r 1 2 3 0 2 2V 5 ta R 2 59

The potential difference across the inductor when it is co nnected to battery is only the induced EMF Right why do we not consider the potential drop developed across induc tor due to connection with positive and negative terminal of battery as we do it in case of resistor connected to batt ery

R 4 20 V 10 6 V R 3 70 V 8 9 V I I Is R 5 50 V3 6 9 V The resistances and voltages in the figure take the values shown above Determine all three currents 1 R 5 60 R ww V R V R 12 R 3 80 R5 V3 13 R3

Three electric bulbs whose resistance are in ratio of 1 2 3 are connected in parallel to constant voltage source The power dissipated them has the ratio P P P3 1 1 2 9 4 39 4 1 p 2 R so P2 P3 26 R 2 3 2 1 4 1 1 1 Ri

20 Find RAB If resistance of each side RO 3R 1 R 3 R 2 2 2 4 8R ALLEN 20 Rie The reading of the ammeter as per figure 21 shown is 1 3 R 2 2R 5 4 SR 2

7 ALLEN Thirteen resistances each of resistance RQ are 17 connected in the circuit as shown in the figure The effective resistance between A and B is 4R 3 RQ R R 2 2RQ 4 2R R R 1 fai v R fanger i B B 4R 3 RQ R 2 2RQ 2R

A wire has a non uniform cross sectional area as 3 shown in figure A steady current i flows through it Which one of the following statement is correct 1 The drift speed of electron is constant 2 The drift speed increases on moving from A to B 3 The drift speed decreases on moving from A to B 4 The drift speed varies randomly vakia tu fferfera fres are an fay n A UNA U t 1 2 AB 3 ABR 4 3 affia art

3 3 RQ 4 20 The total current supplied to the circuit by the 18 battery is 1 A 6V Each of the www 2 2 A www 1 50 20 www 6 02 3 4 A www 352 4 6 A 3 RQ d and after vif 1 1 A ne questionpaper 6V 20 ww 1 50 2 2 A 2R www 6Q 3 4 A www 302 1 4 6 A

A 4 inches rounded cable has insulation resistance of 503 mega ohms If the specific resistance of the insulation material is 3x10 ohm cm per 500 m of length Determine the radius of the conducting material

Consider a thin square sheet of side L and 7 thickness t made of a material of resistivity p The resistance between two opposite faces shown by the shaded areas in the figure is 1 Directly proportional to L 2 Inversaly proportional to t 3 Dependent on L 4 Independent of t 1 f fanger pfa and arter Lyou left cft aufen ufgan anat fauda graf an Telegram ne questionpaper 1 L 2 t 3 L 4 m

A current flows in a wire of circular cross 2 section with the free electrons travelling with a mean drift velocity v If an equal current flows in a wire of twice the radius new mean drift velocity is 1 V 2 V 2 3 V 4 4 none of these Teren voi var und weat firen ya r ngtat en unos segment from u shtua signed in grm 1 V 2 V 2 3 V 4 4

In the figure shown below the maximum and unknown possible minimum resistance X that can be measured by the post office box are Xmax and Xmin respectively Then the ratio of these two resistances is In this experiment we take out only one plug in arm AB and only one plug in arm BC but in arm AD we can take any no of plugs E G D P Q 1000 10010B10 10010000 I ERG 5000 2000 1000 500 100R 200 200 Question Type Single Correct Type unknown resistance X

3 Current falls to zero after time t 2b 4 Current changes at a rate 2b The current in a conductor varies with time t as 43 I 2t 3t A where I is amperes and t in seconds Electric charge flowing through a section of the conductor during t 2 s to t 3 s is 1 10 C 2 24 C 3 33 C 4 44 C 3 4 2b T 2bafd 1 10 C ac Gai 1 p I ved 2 24 C PRAI 3 33 C 2 3t f 21 3 t 4 44 C