Current Electricity Questions and Answers

1 Refer the circuit shown in Fig 1 and find the value of 11 12 13 14 15 16 Ix VC1 VC2 and Vx 10 marks 10 ohm 50 V I 10 mH 12 5 ohm 2 uF 10 ohm 13 TVC 5 ohm 10 mH Ix 31 Fig 1 9 Vx I4 Is 5 ohm 2 uF 16 TV 10 ohm 2 A

33 A square current carrying loop PQRS is placed in a uniform magnetic field which is directed along PS If the magnetic force on QP is F then the force on RS is 1 2F 3 RE TLL Q PL R S F 2 4 F 8

The value of the 3 resistances when connected in star connection is 10 ohm ww 5 ohm www 3 ohm Close 2 32ohm 1 22ohm 4 54ohm

In the given circuit a galvanometer with a resistance of 702 is converted to an ammeter by a shunt resistance of 0 050 the total current measured by this device is Lo Cam 0 05 S 592 0 88 A 0 77 A 0 55 A www 70 92 SV

An inductor 20 mH a capacitor 100 uF and a resistor 50 22 are connected in series across a source of emf V 10 sin 314 t The power loss in the circuit is 1 2 74 W 2 0 43 W 80 79 W 4 1 13 W

An electron moves in a circle of radius 7 cm with uniform speed 5 X 106 m se Find the electric current at a point on the circle Take 10 A 4 x 10 12 A B 4 5 x 10 12 A C 5 x 10 12 A D 3 5 x 10 12 A

The charge flowing through a resistor R 2 Q varies with time as q 3 42 The heat produced in 2 second is about where q is in C and tis in s 330 3 J 341 3 J 345 2 J 326 4 J

A resistor is constructed as a hollow cylinder with inner and outer radii 0 5 cm 1 0 cm respectively and ra rb resistivity p 3 5 x 10 5 m The resistance of the configuration for the length of 5 cm cylinder is x 10 0

3 a a b b 5 4 a a 5 b b 5 23 A mixed combination of 12 identical cells each having EMF 2V and internal resistance 30 are conn such a way so as to draw maximum power P by an external resistor 402 The power consumed by resistance is 2 R 1 4W 2 8W 3 16W 4 32W

A n p n transistor is connected in common emitter configuration in a given amplifier A load resistance of 8000 is connected in the collector circuit and the voltage drop across it is 0 8 V If the current amplification factor is 0 96 and the input resistance of the circuits is 192 02 the voltage gain and the power gain of the amplifier will respectively be 1 3 69 3 84 2 4 4 3 4 3 69 4 4 3 84 1 We see that your answer is in 2 From NCERT 3 NEET 2016

choose 16 In the box shown current i enters H and leaves at C If AB 6 Dc 2 3 HA Y 1GF 6 6 ch 08 the branch in which current is zero 1 BG B O bas elnicG 2 FC 31 E C 2 Finolog on alusta woda lubid edi 3 ED 4 None

A uniform wire of resistance 15 Q is bent to form a circle The effective resistance between point X and Y is 030 020 2 40 7 50

Resistances P and Q are approximately equal When R 4002 the bridge is balanced On interchanging P and Q the value of R for balance is 4052 Choose the closest value of X from the following option R B G K D K

The reading of ammeter in the circuit shown in the figure is 492 492 www A 892 492 www 12 V O 3 A O 2A O 1 5 A O 2 5 A

In the circuit shown in the figure the current I is 24N DIA 3Q D 0 2 wwwo 20 1Q 10 V 9V

At temperature 23 C the resistance of a wire is 100 0 The temperature at which resistance becomes 104 is nearly Given temperature coefficient of resistance of material is 1 5 10 4 C 1 1027 C 827 C 290 C 290 K

Find the voltage across 4 0 resistor for the circuit shown in figure A B 10 92 15 Q2 Only one correct answer C E 25 V 892 492 15 V 10 V 692 5 V 802

A diode of constant voltage drop of 0 4 V at all currents and a maximum power rating of 0 2 watt is connected with a resistor of resistance R as shown The value of R for maximum current will be 2 4 V 50 40 20 0 80 R www

View In English The temperature coefficient of resistance of a wire is 0 00125 C At 300 K its resistance is one ohm The resistance of the wire will be 2 ohm at 1 2 3 4 Correct Answer 4 Your Answer 2 1154 K 1100 K 1400 K 1127 K

The equivalent resistance between the point A and B in the circuit shown in figure when switch S is closed is 622 ww A 020 060 40 030 www 392 S 392 www 692 B

A potentiometer having a wire 10 m long stretched on it is connected to a battery having a steady voltage A cell gives a null deflection point at 700 cm If the length of potentiometer wire is increased by 2 m then the new position of null point will be 740 cm 800 cm 950 cm 840 cm

In the arrangement shown in the figures all the bulbs have same resistance If bulb D gets fused then brightness of bulb B will Battery is ideal A B Increase Decrease Remains unchanged Depend on resistance of D

Each of three bulbs having same resistance can dissipate maximum power Po The maximum power the circuit of three bulbs can dissipate is O 3Po of 2 m 2Po

LEN Consider all batteries are ideal batteries Power developed in 2002 resistance is 20 VT 40 2 20 2 1 100 W 3 180 W 10 V 10 2 40 V 30 22 60 V 50 V 2 60 W 4 50 W Pal A long wire carrying a current 1 is placed along y axis and its one end is at point P 0 a Then find magnetic field at point Q b 0

541 A coil of inductance L and resistance R is connected to a constant voltage source How soon will the coil current attains n n 1 fraction of the steady state value LA

The given circuit is so adjusted that maximum power dissipates across resistor R Then find the value of the power dissipated In watt across R R 37 Uhr Wafa fu a fah R 42 f ca vfufa da zi fa 2 ch 13 2 Ma ARTI 6 V 12 W 19 R 252 24 V 30 35 V

Multiply Choice Questions More Than One Options Q 7 Kirchhoff s junction rule is a reflection of a conservation of current density vector b conservation of charge c the fact that the momentum with which a charged particle approaches a junction is unchanged as a vector as the charged particle leaves the junction d the fact that there is no accumulation of charges at a junction

3 60 cm 4 30 cm The resistance of the filament of a lamp increases with the increase in temperature A lamp rated 100 W and 220 V is connected across 220 V power supply If the voltage drops by 10 then the power of the lamp will be 1 100 W 2 81 W 3 Less than 81 W 4 Greater than 81 W 2

The figure shows a network of resistor each heaving value 1202 Find the equivalent resistance points A and B NKC B

sessment 12 Analyze and solve the following problems Show your complete solution 1 Suppose that a 4 ohm resistor is connected in parallel with a variable resistor x Then the combined resistance for x 0 Find a the combined resistance when x 4 and b R x is given by the formula R x the value of x that results in a combined resistance of 3

mathongo mathongo mathongo mathongo mathongo mathong A 160 wire is bend to form a square loop A 9 V supply having internal resistance of 1 is connected across 0 1 vongo mathong one of its sides The potential drop across the diagonals of the square loop is x10 Vongo

The following arrangement consists of five identical metal plates marked 1 2 3 4 and 5 parallel to each other Area of each plate is A and separation between the successive plate is d The capacitance between P and Q is EA a 5 d b 04 E d 7 3 d 5 EA 3 d 4 0A 3 d 1 2 3 4 5 P

None of the resistors in the circuit shown in the drawing is connected in series or in parallel with one another Find a the current 15 and the resistances b R and c R3 R 4 09 wwwwww 9 0 A R www 6 0 A R 2 00 15 75 0 V 12 0 A R5 2 20 R3 K

Determine the voltage and cur ent of each of the circuit elements in the shown in Figure 15 V Your answer 5002 0 75 A www 1092 Figured 1022 0 25 A

Please explain elaborately why no current flows through t he grounded wire here ge 97 The current drawn from the battery shown in the figure is TUKA a R SV b V 2 R R www R c 2V R Ridings d 3V 2R

In the circuit shown the resistance of each resistor is R 100 Find the resistance in to the nearest integer which is to be connected between points C and D so that the resistance of entire circuit between A and B does not depend on the number of elementary cells A Be 50 ww R www R R x 1 73 R ww FE R R R EXPLANATION www 2R x xR 3R x 3 1 x R 1 x 100 ww R R ww ww R Correct Answer 73 R R C Let resistance added across CD is x then the equivalent resistance between A and B will be independent of the number of elementary cells if the combination of a with the resistors of the elementary cells is itself SO RAB X x www D R

About 10 of the power of a 100W light bulb is converted to visible radiation What is the average intensit of visible radiation at a distance of 1 m from the bulb Assume that the radiation is emitted isotropically and neglect reflection

40 N identical cells are connected to form a battery When the terminals of the battery are joined directly short circuited current I flows in the circuit To obtain the maximum value of I A all the cells should be joined in series B all the cells should be joined in parallel C two rows of N 2 cells each should be joined in parallel D VN rows of VN cells each should be joined in parallel given that VN is an integer

The current i through a rod of a certain metallic oxide is given by i 0 2 V 2 where Vis potential difference across it The rod is connected in series with a resistance to a 6 volt battery of negligible internal resistance What should be the series resistance in 2 so that power dissipated in the rod is twice that of resistance yh Afga ufac H4HSG A G3 qua mai chi 0 2 V1 2 a fu ja q V suh Az 03 04 3 R du 6 fa u my f Ga 1 suf ufa u 07 43 44 sta fach 3 fa fa u af a fa Correct Apower 5

The following figure shows a single turn rectangular coil that has a resistance of 1 25 Q The magnetic field at all points inside the coil varies according to B Bosin 200t where Bo 0 4T What is the magnitude of the current induced in the coil at t 0 009s X Xx X X X X X X X X X X X B 2 0 cm

One metre long metallic wire is broken into two unequal parts P and Q The part P is uniformly extended into another wire R Length of R is twice the length of P and the resistance of R is equal to that of Q The ratio of the resistances of P and Ris A 1 4 B 1 2 C 3 2 D 2 3

Under steady state condition 10 12 ww A BV 0 1 F 201 B O 102 10 2 www 200 ww ww 10 02 D 1002 C Charge on capacitor is 0 4 C Charge on capacitor is 0 2 C O Current in the resistor between point A and B is 0 3 A O Current in the resistor between point A and B is 0 4 A

To get maximum current in a resistance of 3ohms one can use n rows each of m cells connected in series connected in parallel If the total number of cells is 24 and the internal resistance of each cell is 0 5 ohms then A m 12 n 2 B m 8 n 3 C m 2 n 12 D m 6 n 4

If the potential difference V applied across ends of a conductor of leng I and radius r If diameter of the wire is doubled the drift velocity of fr electrons in a conductor will be a c 2Vd V 2 b Va d V 4 TEECC 982

A wire has resistance 12 2 It is bent in the form 5 of a circle The effective resistance between the two points on any diameter is equal to NCERT XII 1 109 1 12 92 2 6 2 3 322 4 24 92

n rows each containing m cells in series are joined in parallel Maximum current is drawn from this combinatic in a 3 n resistance If the total number of cells used is 24 and the internal resistance of each cell is 0 5 fi the values of m and n

A ring of a radius r 16 cm is made of a wire of uniform cross section of radius a 1 0 mm Resistivity p of the material of the wire is not uniform and varies with angular position measured from a fixed radius according to the given graph How much maximum resistance between a pair of points on this ring can be obtained p m2 m 1 0 0 5 C

A laptop battery has an emf of 10 8 V The laptop uses 0 80 A while running 1 How much charge moves through the battery each second 2 By how much does the electric potential energy of this charge increase as it moves through the battery

If two conductors say A and B of same material are placed in contact with eac h other and not in contact with the eart h Then say if one of the conductors ha s an excess of 1e then will that charge travel between the conductors indefinit ely

A battery of EMF 120 0 V is connected to a 38 0 ohm resistor As a result current of 2 0 A exists in the resistor The rate at which energy is being dissipated in the battery is in Watts O 55 00 132 00 88 00 None of these 105 CO