Current Electricity Questions and Answers

In the circuit shown in figure the 50 resistance develops 45 Js 1 of heat due to the flow of current through it 11mm 62 Imm 222 The value of I is Select an answer A B C 1 A 2 A 12 3 A ww 522 9 2

1 Resistance Power Electric iron Current ver 1 2 C A A List 2 B B A Watt B Heating effects of electricity C Depends on length of the conducte D Rate of flow of charge C C

Two cells of unequal emfs E and E2 and internal resistances r and r2 are joined as shown in the figure Vp and Vo are the potential at P and Q respectively P A B HH C Select answers HH E T T1 72 E2 F2 Up Vg The potential difference across both the cells will be equal Era Eri T1 12 Q none of thong

Galvanometer G having full scale deflection current and resistance R is used in combination with resistances to form an ammeter whose range 1 is given in Column II Match the entries in Column l with the entries in Column II Column l Q1 Q2 Q3 04 R www 2R www www RR www R www R www 4R www Column II A1 is maximum A2 3 ig A3 2 ig A4 6 ig

A carbon resistor has a set of co axial coloured rings as shown The resistance of the resistor is 0 M Green Blue Yellow Gold 56 10 5 Q 36 x103 10 Q 56 104 5 Q 36 104 10 8

In the given circuit current 352 www E 10 V A Select answers B C 1 52 D www 202 8 02 www 202 www 202 80 40 Imm Imm 202 202 through the 3 resistance is 1A through the 10 resistances is 0 5 A through the 452 resistances is 0 5 A through the 4 resistance is 0 25 A

C d 400 2 3 In a potentiometer experiment two cells of e m f E and E are used in series and in www conjunction and the balancing length is 58 cm If polarity of E2 is reversed then the balancing length becomes 29 cm The ratio E Ez is a 1 1 b 2 1 c 3 1 d 1 2

Two wires that are made up of two different materials whose specific resistances are in the ratio 2 3 length 3 4 and area 4 5 The ratio of their resistances is Select an answer A 6 5 B 6 8 C 5 8

The power supplied by the cell in the shown circuit will be 2 W 32 wwwwww 62 ww 2 V

1 Does therelaxation time in a conduct or depends on electric field i e if I chan ge the electric field will the relaxation ti me be changed or will it be constant 2 pls also tell the other factors on whic h the relaxation time depends

A 1m 30 Two balls each of mass 1gm are suspended by insulating strings each of 1m At equilibrium angle between string and vertical is 30 Find charge on any one ball 1 0 8 C 3 1 6 C 2 1 C 4 2 4 C

56 Each resistor shown in figure is an infinite network of resistance 1 2 The effective resistance between points A and Bis 192 192 1922 a less than 10 e more than 1 2 but less than 3 192 192 192 www 192 192 A www B b 1 Q d 3 Q 192 192 D 1 92 192 192

A charge particle q lies at the centre of two concentric hollow spheres of inner radii 2R and 6R and outer radii 4R and 8R respectively The amount of work has to be performed to slowly transfer the charge q from center through the orifice to infinity is 2 Xq Find the value of X 192 TEOR 6R 8R 4R q 2R

In a circuit voltmeter reads 3V and the ammeter reads 2A Then wrong option is Question Type Single Correct Type 1 the resistance R is 1 ohm 2 the emf E is 12 V 20 wwwwww 2 502 3 the current in 30 resistor is 1A 30 6V R E

For the circuit shown in the figure R 2R2 When R3 Is Increased from U infinity current through the battery changes from A to 4 A www b 12 R R 60 a R 30 R 50 18 V Walue of R and R is R www www R Read Less

5 x100 20 in a potentiometer circuit the emf of driver cell is 2 V and internal resistance is 0 5 2 The potentiometer wire is 1 m long It is found that a cell of emf 1 V and internal resistance 0 50 is balanced against 60 cm length of the wire Calculate the resistance of potentiometer wire ristance of potentiometer wire

A i 1 13 Three resistors having resistances r r2 and are connected as shown in the given circuit The iz ratio of currents in terms of resistances used 11 in the circuit is 2 r r2 r1 r3 r1 r2 r3 r2 r2 r3 r1 i r2 W w iz r3 B

Paragraph for Question Nos 7 to 9 For the circuit shown in the figure initially capacitor C is uncharged Switch S is closed at t 0 Vo 2R Vo 4R 2V0 R www 3R 2R At the instant when potential across capacitor is the current through battery is I then www C Read Less

If resistance of voltmeter is 40 0 then error in reading of voltmeter is 5n Find the value of n wwww 20 2 Answer 00 www 4002 60 V 01 02 3 4 5 06 07

For the circuit shown in the figure R 2R When Rs is increased from 0 to infinity current through the battery changes from A to 4 A wwww b 18 V wwww R Value of R and A is DR 60 DR 30 R 50 DR 2 50 Read Less

The lengths of the three wires of copper a the ratio of 1 4 8 and their masses are in ratio of 5 3 1 The ratio of their elec resistance is 1 1 3 5 3 1 25 125 2 3 80 960 4 125 15 1

In the series combination of 18 cells each cell having emf 6 V and internal resistance 2 ohm if three cells are wrongly connected ie their polarity is opposite to remaining 15 cells then total emf and internal resistance of this combination will be 1 36 V 36 2 2 72 V 30 02 3 90 V 36 0 4 72 V 36 02

5 Two conducting plates A and B are placed parallel to each other A is given a charge Q and B a charge Q The surface charge density at the inner surface of the plate A is S surface area of each face of plate 1 3 Q Q 2S Q Q 25 m 2 4 Q 2S 2S

2 25 In the given circuit initially switch S is closed and S and S3 are open After charging of capacitor at t 0 S is open and S and S3 are closed If the relation between inductance capacitance and resistance is L 4CR then the time in sec after which current passing through capacitor and inductor will be same is x 10 N Given R ln 2 m L 2mH iq Isma S2 S E 2R www C R www S3

wo identical galvanometer and two identical resistors having resistance Reach are to be connected to make a voltmeter of maximum range possible Resistance of galvanometer is G All elements should be connected in series For G 2R they have to be connected in series For G 2R galvanometers have to be connected in parallel and then this combination is to be connected in series with resistors Connection arrangement does not depend on value of G

For the circuit shown in the figure initially capacitor Cis uncharged Switch S is closed at 1 0 R wwww 2R DI V 4R Paragraph for Question Nos 7 to 9 2R At the instant when potential across capacitor is the current through battery is then 01 20 3R Read Less

Two identical galvanometer and two identical resistors having resistance Reach are to be connected to make a voltmeter of maximum range possible Resistance of galvanometer is G All elements should be connected in series For G 2R they have to be connected in series For G 2R galvanometers have to be connected in parallel and then this combination is to be connected in series with resistors Connection arrangement does not depend on value of G

wo resistors of resistance Rand 3R have thermal coefficients of resistance a and 2a respectively Equivalent thermal coefficient of resistance for the combination onnected in parallel is 50 50 11 16 21 12 17 22 55 EV m

or the circuit shown in figure value of resistance R is adjusted such that power dissipated in resistance R is maximum and equal to Po Value of P 6 V 302 wwww

In the potentiometer circuit as shown potentiometer wire AB is of length 3 m Resistance of wire AB is 3 Q Null point shifts by 50 cm when switch Sis closed Internal resistance of cell of emf 2 V is Driver cell is ideal 10 V 2 V 3 0 22 020 0 5 Q 13 C 792 B 84

Column I gives certain physical terms associated with flow of current through a metallic conductor Column II gives some mathematical relations Match involving electrical quantities Column I and Column II with appropriate relations Column II A Drift Velocity B Electrical Resistivity C Relaxation Period D Column I Las 2 3 C P CON Q nevd eE R Current Density A R B P C S D Q A R B Q C S D P A R B S C P D Q D P S m 2 ne p T m E J

In the wheatstone bridge network shown in figure The current passing through battery is B A 152 292 6 V 4 A 3 A 2 A ww D 5Q 292 ww 422 www 192 C

20 cm In the figure shown below is a meter bridge set up with null deflection in the galvanometer The value of unknown resistance Ris www 55 2p O 13 750 220 Q O 1100 Tor Review ww R 01 25 hr mir

CAREER INSTITUTE 4 A galvanometer may be converted into ammeter or 44 voltmeter In which of the following cases the resistance of the device will be largest Assume the maximum range of galvanometer to be 1 mA 1 An ammeter of range 10 A 2 A voltmeter of range 5 V 3 An ammeter of range 5 A Magnet treff af fr mart aftre 1 ST 10 A 2 5 3 35

n meter bridge experiment as shown null point is obtained at Pwhere AP 60 0 cm Shift in null point when resistance X is shunted by 240 resistanc X 802 O 10 cm leftwards O 10 cm rightwards O 20 cm leftwards O 20 cm rightwards B

me temperature co efficient of resistance of a wire is 0 00125 C 1 At 300K its resistance is 20 The resistance of the wire will be 2 5 02 at temperature about 120 C 234 C 310 C O 27 C

wo shopkeepers A and B having their shops side by side decided to economies by connecting their bulb in series They agreed that each will install a 100W bulb in their own shops and that they would pay equal hares of the electricity bill However both decided to try to get better lighting of the other expense A installed a 200 W bulb and B installed a 50W bulb which shopkeeper will be in advantage DA B O Both A and B because connection is in series O None of these

For the circuit shown in the figure R 2R When R3 is increased from 0 to infinity current through the battery changes from A to 4 A 1 R www 12 R R 60 R 30 a R 50 b R wwww R3 18 V Value of R and R is R Read Less

An ammeter and a voltmeter are connected in series to a battery with an emf 6 0 V When a certain resistance is connected in parallel with the voltmeter the reading of the voltmeter decrease n 2 0 times whereas the reading of the ammeter increase the same number of times Find the voltmeter reading after the connection of the resistance A 2 V End 0 B 4V C 8V D 18V galvanometer has resistance 1000 and it requires current 100uA for full soolo deflection

Galvanometer G having full scale deflection current Ig and resistance R is used in combination with resistances to form an ammeter whose range i is given in Column II Match the entries in Column l with the entries in Column II Column l Q1 Q2 Q3 Q4 R 2R www R R G R R 4R Column II A1 i is maximum A2 3 ig A3 2 ig A4 6 ig

Q No 11 The equivalent resistance between the terminal points A and B in the network shown in figure is R www e Correct Answer 1 EFERERE 7R 5 5R 6 7R 12 5R 12 R R ww R www B View

www 32 Numerical Value Type The current in the 50 resistor will be Answer Read More ZO 6 V 522 www A www 62 4 V 05 06 07

The coil of a galvanometer has resistance 50 and range of V volt In order to extend its range to 4V volt the resistance in ohm that should be connected in series is Answer O o OI O z O 3 0 4 05 06 07 8 9 Oo Or Oz 03 04 05 06 07 O 8 09

Two shopkeepers A and B having their shops side by side decided to economies by connecting their bulb in series They agreed that each will install a 100W bulb in their own shops and that they would pay equal shares of the electricity bill However both decided to try to get better lighting of the other expense installed a 200 W bulb and B installed a 50W bulb which shopkeeper will be in advantage O A OB Both A and B because connection is in series O None of these

A system consists of four equal charges Q placed at the four corners of a square and another charge q is placed at the centre of the square then the value of q for which the system is in equilibrium is 1 2 2 0 2 1 2 2 1 2 A G Q h

The resistance of the rheostat shown in figure is 30 2 Neglecting the ammeter resistance the ratio minimum and maximum currents through the ammeter as the rheostat is varied will be 5 5V A 2 5 B 83 15 300 300 6002 C ww 300 43 D 19 43 om and Y respectively If a

Two charged metal spheres of radii R and 2R are temporarily placed in contact and then separated Choose CORRECT option Larger sphere has larger charge density Smaller sphere has larger charge density Both have same charge density None of the above

In meter bridge experiment null point is found at l 60 0 cm Value of 6 Q resistance is known to be accurate Value of R is found to be 9 20 Find the value of n n R www 622 www B Answer 00 01 02 03 04 05 06 07 08 09

Final value of 1 if VBE 0 3 V in given circuit 85 Characteristic B 100 6V 10k ww 2k2 ww lkn 12V In given circuit if V 0 3 V then value of I will be B 100 1 51 A 3 26 A 2 11 A 4 5 5 LA 86 1 3 How many minimum obtain boolean expre 1 3

In the circuit as shown in figure the 502 resistance develops heat 10 24 cal s due to a current flowing through it Calculate 1 heat developed per second in the 202 resistance ii the potential difference across 602 resistance 1551 1 0 31 552 istor A 202 www 602 992 www