Current Electricity Questions and Answers

1 In the shown circuit when the voltage between A and B is 16 V the voltage betwe C and D is 8 V When the voltage between and D is 15 V what is the voltage in V between A and B A 202 202 Bow 1 7 5 2 5 R 80 802 3 3 C D 4 4

32 A pendulum bob of mass 30 mg carrying a ch of 20 10 C is at rest in a uniform horize electric field of 20000 N C The tension ir thread of the pendulum is g 10 m s 2 4 10 N 1 5 10 N 4 2 10 N 3 3x10 N

SECI PHY SEC II ww R PHY SEC III CHEM SEC I C HH m In the AC circuit shown in figure the capacitance of the capacitor is chosen in such a way that the average power P deliveres source to the circuit is 500W with minimum current If R 1092 then the value of capacitive reactance in ohm is X ww R CHEM SEC II 4R 3 CHEM SEC II MATH SEC I MATH SEC II MATH SE

Two capacitors C 1 F and C2 2 F are initially charged to potential difference of 100 V and 20 V respectively and then joined as shown in figure Find the amount of charge in C that will flow through the switch S when it is closed S it

Q 1 54 A part of a larger circuit is shown in the figure Both batteries shown have internal resistance 12 each If the points A and B are equipotential and a current 2 A flows from A towards B then the emf E in Volts is Awwww B 352 14 8V 292 E

The total momentum of electrons in a straight wire 3 of copper of length 1 metre carrying a current of 16 A is 1 91 x 10 2 kg m sec 2 91 x 10 5 kg m sec 3 91 x 10 4 kg m sec 4 91 x 10 kg m sec 116 Afe Batt 1 91 x 10 2 kg m sec 2 91 x 10 5 kg m sec 3 91 x 10 4 kg m sec 4 91 x 10 kg m sec

THE AD If current through 402 is 2A then calcu potential difference across A B www 202 1 8V 402 www ww 2 16 V 2A www 202 3 4 V B 4 N

Two cylindrical resistors one of length radius r and the other of length 3 and ra 3r are made of the same materials It resistance of the smaller one is R what i resistance of the larger one 2 3R 1 R 3 3 9R 4 A cuboid shaped metal structure has follo

Consider a circuit made of a wire with uniform resistance in a shape of a circle as shown in the picture The circle is connected diagonally from point C to point B with the same type of wire If the current passing through the circuit is in what is the current passing through the wire BC as a function of angle 9 1 0 3 20 x 2 2 x 20

Voltmeter of resistance 102 and ammeter of resistance 100 are attached in the following circuit with switches S and S ww R 1052 150V Column I switch position 1 II 2 II 3 III 4 III Column II reading of voltmeter ammeter I 0 7 5 A II 50 V 10A III 0 0 IV 150 V 0 P S open S closed Q S closed S open R S open S open S S closed S closed PQ RS III I IV III IV I II II IV I I IV

3 9K A cuboid shaped metal structure has following specifications as shown in figure 3cm Icm 2cm The structure is connected to a battery acros opposing faces The resistance shall be 1 Minimum when battery is connected acros 1cm x 2cm faces 2 Maximum when battery is connected acros 1cm x 3cm faces 3 Minimum when battery is connected acros 3cm x 2cm faces 4 Same in all of above

D Two metallic spheres of radii a and b are placed away from each other and are connected by a thin conducting wire A charge Q is given to one of the sphere The charge on each sphere at electrostatic equilibrium is 1 9 2 9 Qb a b Qa a h 92 92 Qb a b Qb a h

A constant electric current I is passed through a straight conductor of length C If S is specific charge of electron then the total momentum of electrons is 1 IS 2 3 21 S S An electric field travelling in a conducto

PERDADERNO LONGE GY 182 45 In the shown circuit find the total current through the battery in amperes 302 www www 602 7 50 P 1 IA 2 2 A 3 3 A 4 4 A 46 In the circuit shown in the figure below which of the following statement is incorrect 1 5 A 11 3 A 202 www 10 0 50 20 10 1 The potential at P is 7 5 V 2 The potential at Q is 1 V 100 www 402 www 20V 302 3 The potential at R is zero 4 The potential at S is zero 47 In the circuit shown find the current in branch AB of the circuit 562 562 10 1002 2 0 5A 4 Zero 48 A potential divider is used to give outputs of 2 V and 3 V from a 5 V source as shown in figure Which values of resistances R R and R gives the correct voltages 49 5Vo Vo 2V www R A 60 1 k R 1 1 kn 2 2 k 1 km2 3 3 km 2 k 4 3 km 2 km2 3 km2 In the below circuit the current in each resistance is 1 19 21 2 3 12 2 R www 6R R R ad wwwwwwwwww ww 60 2V 2V 2V 1 0 5 A 2 0 A 3 1 A 4 0 25 A 50 Which of the following options is are INCORRECT regarding the below diagram 0 3V 0 2V R 2 k2 2 km2 2 km2 ww C 602 24V 1 1 8 A 2 1 4 A 3 1 0 4 1 8 A 51 A battery of internal resistance 4 52 is connected to the network of the resistance as shown in figure If the maximum power can be delivered to the network the magnitude of R in 2 should be E 402 www 10 ww 4R B 2R 2 84 19 2 4 7 2

3 A potentiometer wire is 100 cm long and a constant potential difference is maintained across it Two cells are connected in series first to support one another and then in opposite direction The balance points are obtained at 50 cm and 10 cm from the positive end of the wire in the two cases The ratio of emf s is ME 2016 I a 5 1 b 5 4 d 3 2 Janidaoo A c 3 4

Queation No 19 If a ideal wire is connected between two points then potential difference between that two points Zero Non zero May be zero may not zero None

An electric box contains three e m f sourd as shown in the figure Given 26 26 volt r r r 192 61 LJ 1 e m f of the electric box is 3 2 Volt 2 c m f of the electric box is 1 2 volt 3 internal resistance of the electric box is 3 2 4 internal resistance of the electric box is 1

the effective resistance across A and B in the given circuit A 1 52 3 15 2 1092 20 23 wwwww 20 22 392 www 1052 www 223752 www 1092 2 10 S 4 20 2 B 53

In the part of a circuit shown in Fig potential difference V V between p G and H will be www 4015 2A 3V 20 ww 10 5V 1 0 V 2 15 V 3 7 V Calculate the current in wire BD 1A JA 4 3

Problem 3 57 A heater is designed to operate with a power of 1000 watt in a 100 V line It is connected in combination with a resistance of 102 and a resistance R to a 100 V mains as shown in the figure What will be the value of R so that the heater operates with a power of 62 5 W 1002 B Heat www R 400 V of coil

The resistances P Q R and S in the bridge shown are adjusted such that the deflection in the galvanometer G is zero when both the keys K and K are inserted The galvanometer will show a momentary deflection if P K G S K C

A potential difference of V volts is applied on two parallel electrodes separated by a distance of 4 0 x 10 2 m The electrons of very low energy are injected into the region between the electrodes which contains argon at low pressure The average distance the electrons travel between collisions with argon atoms is 8 105 m The ionization energy of argon atom is 16 eV Estimate the minimum value of V in kV such that the electrons will cause ionization in argon atoms by collision

For the values of R1 608 R2 608 R3 896 Vs 30 If the real diode offset voltage 0 7V were conducting then the value of voltage source VB should be check all that apply R Vs Figure 1 a 17 00 O b 17 c 13 0 d 13 3 e 29 0 VD VB

27 In the following figure the equivalent resistance of 27 Pfaf the circuit between the points P and Sis 592 20 S P Q 152 802 502 502 502 10 Q 2 30 52 R S 1 55 2 3 48 4 34 2 28 In the given figure current in some branches of an electrical circuit is shown Value of Iis 28 15 Pwww 8 1 55 2 3 48

In the shown infinite ladder network an ideal battery of EMF E 4 17 1 volt is applied Choose the correct options 1922 1 EI 2023 12 1 2 1 2 17 3 A I 8A 10 I 4A YI B E 4 17 1 Volt 102 D 4 C 192 C 22

1 Given below are three circuits with their time constants R 1 2 sec 3 6 sec then find time constant in second of circuit shown below C R 2 4 sec 4 I sec

Resistivity of the rod of length 1 1 m varies with x as 1 22 m A point C is at a distance from end A of 21 A 2 the rod If VAC VBC denotes potential difference magnitude between points A C and B C then cross sectional area of rod is 1 m F X 1 1m Px HH VAC 53 E 4 volt Volt 7 Volt Vec B

Ques 15 SMCQ The voltmeter has some internal resistance and reads 18 V for the circuit given 240 A ww 30V Current dissipated by the battery is 0 25 A B 0 5 A C 1 A 500 D 1 5 A

Galvanometer G shows zero deflection in the given circuit Find the value of resistance R if batteries have negligible internal resistance 4V A B R 5000 2500 50002 12V

In the circuit given below R 20 Find 12 and i3 using mesh analysis 12 V 11 1 www 292 iz 3 A 492 iz The value of it in the circuit is 3 816 A The value of 12 in the circuit is 0 184 A The value of i3 in the circuit is 2 816 A www R 2

Read the paragraph carefully and select the correct choice in the questions given below A battery consists of ten identical dry cells in series each of electromotive force 12 V and internal resistance r The battery is connected across the two ends A and B of a load consisting of five resistors as shown below The battery transfers maximum power across the load ww 3002 wwwwwww 600 300 300 wwwww 3002 BATTERY B

the circuit shown the ammeter reading is 0 5 amp but when two resistors from the group of identical resistors connected parallel are removed the ammeter reading changes by How many resistors were connected in parallel 100 21 10022 10v R www www 192 www 652 Group of resistors connected in parallel k

A charge of 2 C experience electric force of 2000 N when kept in uniform electric field What is potential difference between two points separated by a distance of 1 cm along the field O 20 V O 40 V O 10 V O 60 V

Find the potential difference between the points a and b If the points a and b are joined by a resistance of 5 2 calculate the current through this resistance 292 A 292 www 29 b 12 V 192 110 V 192 www 392 8 V 192 19 B 192

2 A resistance wire connected in the left gap of a metre bridge balances a 1002 resistance in the right gap at a point which divides the bridge wire in the ratio 3 2 If the length of the resistance wire is 1 5 m then the length of 12 of the resistance wire is 2020 a 1 0 10 m c 1 5 10 m b 1 5 x 10 m d 1 0 10 m

In meter bridge experiment as shown null point is obtained at P where AP 60 0 cm Shift in null point when resistance X is shunted by 24 Q resistance is X A G P V O 10 cm leftwards O 10 cm rightwards 20 cm leftwards O 20 cm rightwards 822 B

9 Electrical energy costs 25 paisa per kilowatt hour Assuming that no energy is wasted the cost of heating 4 6 kg of water from 25 C to the boiling point is 1 10 paisa 3 20 paisa 2 15 paisa 4 25 paisa

Q 12 75 A galvanometer of resistance 10 Q2 breaks down if the current through it exceeds 0 1 A To convert it into an ammeter that can measure current up to 10 A a shunt resistance is connected in parallel with it The net resistance in Ohms of the galvanometer now becomes 0 01 0 05 0 1 0 2

Q 21 75 Both batteries and the ammeter in the given circuit are ideal and Ris a variable resistance The value of R in Ohms for which the ammeter shows zero reading is 192 12V A R 692 www 3Q 292 30V

A conducting solid sphere is joined electrical circuit as shown in figure 2R 1 V Va 3 V V R 2 R 2 www Two imaginary points A and B are inside the sphere For given conditions 2 V V 4 Data insuffi

R and R such that R R are connected in series across an ideal battery the rate of heat dissipation is When the resistances are connected in parallel across the same battery the rate of heat dissipation is If the ratio H H 4 25 the ratio R R is 2 3 1 3 1 2

Q 7 75 In the circuit shown the potentiometer wire PQ has length 120 cm and total resistance 10 22 The main cell E has emf 24 V and internal resistance 222 The jockey J is moved on the potentiometer wire PQ to find the balancing point If the current through the galvanometer is zero for the length PJ 70 cm the emf of the cell E is P E E 11 7 V 12 4 V 12 9 V G Q

Q 17 75 A non ideal battery of internal resistance 12 is connected across a wire of resistance 20 2 The current through the battery is 1 Now the wire is cut into 4 equally long pieces and the pieces are connected in parallel across the same battery The current through the battery is now 28 23 1 HS 281

Is applied across a metallic conductor Consider the following statements 1 at any instant the velocity of all electrons in the conductor is approximately equal to the drift velocity 11 the number of electrons passing through a cross section of the conductor in a given time interval is proportional to the drift velocity Which of these options is correct Both 1 and II are correct 1 is correct and II is incorrect II is correct and 1 is incorrect Both I and II are incorrect

The magnetic field at the centre of dotted circle i the arrangement shown is L 1 Hol Hol 4R 2 R Hol R R R O R 2 Hol 4R

and E of emf 12 V each and internal resistance 12 each are connected in series across a 10 Q resistance such that the positive terminal o E is connected to the negative terminal of E The potential difference in Volts across the terminals of E becomes 6 9

Q 2 75 In the metre bridge circuit shown AE is a uniform wire of length 100 cm and two resistances R and R are connected in the gaps as shown If the current through AJ is zero for length AJ 30 cm the ratio R is A R try t J R B

The figure shows a circular wire loop of radius 2 m carrying current 1 A placed in a uniform magnetic field B 4 T The tension in the wire will be N X X X X Bx Answer 0 8 R X 0 809 X X X X 1 2 3 4 5 6 7 9 1 02 03 4 5 6 7

Potentiometer It can measure potential difference without drawing a current from the circuft Thus it accurate reading and it can measure emf of a cell AB Potentiometer wire of resistance R and length Any two point C and D are separated by length R VCD IRCD Ep R R L all other factors are constant VCD 1 X 1 1 www Rn B

In the figure shown the current through 20 resistor is 1 2 A 2 0 A 592 252 www Question Type Single Correct Type 3 4 A 10V 1092 www T20V