Current Electricity Questions and Answers

An ideal battery of 4 V and resistance R are connected in series in the primary circuit of a potentiometer of length 1 m and resistance 5 92 The value of R to give an potential difference of 5 mV across 10 cm of potentiometer wire is 1 480 9 3 495 2 JEE Main 2019 2 490 22 4 395 2

Find the reading of ammeter connected in the given circuit diagram resistance of ammeter 18 92 1 3 A 3 6 A 4Q 12 2 322 30 V A 622 2 4 A 4 1 A

In a meter bridge experiment S is a standard resistance R is a resistance wire It is found that balancing length is 25 cm If R is replaced by a wire of half length and half diameter that of R of same material then the balancing distance in cm will now be JEE Main 2020 R S G

3 BR BR 5 A battery of emf 40V and internal resistance 202 connected to a bulb of resistor 1892 What is efficiency of the battery 1 10 3 7 5 E 40 V r 202 11 R 180 2 45 4 90

29 Two resistances R and R are made of different materials The temperature coefficient of the material of R is a and that of the material of R is The resistance of the series combination of R and R does not change with temperature then the ratio of resistances of the two wires at 0 C will be B a

When an electric dipole is placed in uniform electric field a couple acts on it The moment of couple will be maximum when dipole is placed Along the direction of electric field Opposite to direction of electric field At some acute angle with the electric field Perpendicular to direction of electric field

In the circuit shown all the batteries and the ammeter are ideal and Ris an unknown resistance If the ammeter reads 2 A then which of these options is are correct P 192 www 8V 1923 12V Q 652 www 302 S 30V The potential difference between the points P and Q is 10 V The potential difference between the points P and S is 7 V The current through the 6 resistance is A The resistance Ris120

20 In the meter reads 30 V when connected across tance Calculate what the same voltmeter reads when it is connected across 300 2 resistance www 300 2 60 V 30 V www 400 SQ 2 A C 32 LA A IIT 90 Ans 22 5 V 392 ing B D 202 322 Fig 3 70 Fig 3 71 21 Find the potential difference between points A and B i e VA VB in the network shown in Fig 3 71 1M

Use the circuit diagram below to solve all the problems on this assignment RT 00 10V r unit 700 r2 2502 ww r5 800 r3 1002 1V M T4 740 OA 56 3102 What is the total resistance offered by the circuit shown RT unit What is the total current offered by the circuit shown or in other words how much current is flowing through the battery IT 0

What is the total resistance of the circuit shown below 360 ww 360

What is the voltage on an electrical device if it has a total internal resistance of 1600 and 6 3A of current is flowing through it Desmos Calculator V unit

What is the total resistance of the circuit shown below 113 Q www R HE 545 Q www R

R www 420 V 120 V www R 116 V www R3 The circuit above has a power source of 420 V and 120 V is dissipated through R2 and 116 V is dissipated through R3 How much electric potential is dissipated through R1 Units

What is the electric potential of a power supply if it is providing 120 Watts of power to a 980 Ohm applicance V unit

www ww R R This is a diagram of a series circuit Three resistors are connected to a 15 Volt battery The resistors have the same resistance such that R R2 R3 1700 2 According to the way the circuit is set up what is the voltage drop across Resistor 3 V3 unit

What is the length of the material you are conducting electricity through if the resistance is 3855 2 the cross sectional area is 0 001 m and the resistivity is 4 4 m Desmos Calculator unit

A 24 3V battery is connected to a circuit with total resistance of 7950 which will cause how much current to flow Desmos Calculator

If a particular resistor is using 336W because 5 9A is flowing through it then what is the voltage drop across that resistor Desmos Calculator V unit

How much power is a circuit using if 2 2A is flowing through the power supply which is providing 178V Desmos Calculator P unit

If a material has a resistivity of 1234 32 m a resistance of 315 2 and a length of 0 097 m then what is the cross sectional area of the object Desmos Calculator A unit

Select all CORRECT factors that affect the resistance of a wire Material copper has lower resistance then steel for example Temperature heating a wire increases it resistance Length shorter wires have greater resistance than longer wires

Students in a lab group have designed a circuit but they are having trouble determining whether it is a series parallel or mixed circuit All that they have available to them to help they make this determination are the components of each circuit two 1 5 V batteries wires and three light bulbs They ask their teacher to tell them what type of circuit they have built and she challenges them to consider what they know about series and parallel circuits and collect some observations to help them decide What step would provide enough evidence to allow the students to determine with certainty the type of circuit they have Try adding an additional bulb and check on the change in brightness of the other bulbs Detach the wire connecting any two bulbs Unscrew each bulb in the circuit one at a time to determine how it impacts the other bulbs Unscrew the first bulb in the circuit and determine if the other bulbs remain lit

Question 29 3 points Listen A student has collected data from a simple circuit built with a 10 resistor a 20 resistor and a 302 resistor in order to identify the type of circuit The student concludes that it was a series circuit What evidence would best support the students claim The student can measure the current for each resistor A series circuit would have the same current for each resistor The student can measure the voltage for each resistor A series circuit would have the same voltage for each resistor The student noticed that as resistors are added the total amount of current in the circuit increased The student noticed that as resistors are added the total amount of voltage in the circuit increased

Listen A group of students is conducting an investigation of a circuit with one battery and one resistor in order to find the resistance of the resistor They have collected voltage data and are planning to measure current next How should they measure current and what relationship would they expect to find Trial 1 2 3 Voltage Across Resistor 1 5 V 3 0 V 9 0 V Current Through Resistor The students should measure the current with an ammeter connected in parallel They should find that as voltage increases current increases proportionally The students should measure the current with an ammeter connected in series They should find that as voltage increases current decreases proportionally The students should measure the current with an ammeter connected in parallel They should find that as voltage increases current decreases proportionally The students should measure the current with an ammeter connected in series They should find that as voltage increases current increases proportionally

A device that measures the amount of current in a circuit is a n O 1 potentiometer 2 resistor 3 voltmeter 4 ammeter

Listen V IR E Pt Series Circuits VT V V V 1T 1 12 1 RT R R R 2 400 Amps P IV 1 67 Amps C rPt Parallel Circuits V V V V3 17 1 1 1 1 1 1 RT R R 1 R3 A 200 W lightbulb is connected to a 120 V power supply What is the current through the bulb while it is operating

at wires have lower resistance than skinny wires Question 34 1 point 4 Listen Comparing and contrasting DC and AC current please check all that are correct direct current electrons flow in one direction alternating current electrons switch direction of flow direct current source in electrical qutlets batteries

Listen An ohm is a unit of 1111 which is equivalent to a n 1 resistance joule coulomb 3 2 power Newton meter power joule coulomb 4 power volt ampere 1111

17 20 3 5 21 18 24 27 30 33 36 Listen V IR E Pt Series Circuits V V V V 17 1 1 1 RT R R R P IV 10 Ohms and 8 Amps 2 5 Ohms and 8 Amps C rPt Parallel Circuits VTV V V 17 1 1 13 1 1 R R R 1 1 RT A series circuit contains a 20 V battery wired with two bulbs each with a resistance of 50 This question requires 2 calculations What is the total resistance of this circuit and How much current flows through this circuit

Time Left 1 29 41 ved Neftali Moreno Miranda Attempt 1 4 The brightness of the remaining light bulbs will not change Question 2 3 points 4 Listen Check all of the following total resistances that could be produced by using up to three 3 2 ohm resistors in some arrangement 1 5 ohms 2 3 ohms 3 4 ohms 4 2 ohms

A poli The diagram below shows a simplified schematic for an adjustable electric heating blanket The switch may be connected to point W X or Y depending on the desired level of warmth a Calculate the current generated in the blanket when the switch is connected to point X Show your calculations and include units in your answer b Calculate the power generated in the blanket when the switch is connected to point X Show your calculations and include units in your answer c Explain why a fuse at point T would be more effective in this circuit than a fuse at point U d Identify which point the switch should be connected to in order to generate the most warmth Explain your answer Multiple position switch 20 V Y X W T Electric heating blanket 1202 ww 502 www 302 www 502 www U

An engineering student is attempting to determine the currents through each branch of the circuit in the figure below The student has assumed the currents are in the directi the figure The student has found that the current I is 3 77 A and the values of E and R are unknown R A 8 24 0 V 3 000 14 6 00 n What is the magnitude of the current I in A Does the direction of the current I match the direction shown in the figure Yes 1 points in the direction shown No 1 points opposite to the direction shown The magnitude of I is zero so there is no direction What is the magnitude of the current I in A Does the direction of the current Jy match the direction shown in the figure Yes 13 points in the direction shown No I points opposite to the direction shown The magnitude of I is zero so there is no direction

The figure below shows with two batteries and three resistors The potential difference across the batteries and the resistance of each resistor is given in the figure 12 0 V a 7 80 V A 2 00 www ww V 6 00 Q 4 00 2 a What is the current in A in the 2 00 Q resistor Enter the magnitude ob b What is the potential difference in V between points a and b that is AV V V

The figure below shows a combination of connected resistors between points a and b The resistance 12 0 Q www www 6 00 A A A W a What is the equivalent resistance in of the entire combination between points a and b A 5 00 A 4 00 b A battery with a potential difference of 21 2 V is connected to the combination with one terminal connected to point a and the other connected to point b What is the current in A in each resistor 12 00 6 00 Q 5 00 Q 4 00 Q 8 00 Q www 8 00 b

If electrical energy costs 0 12 per kilowatt hour how much do the following events cost a To burn a 100 W lightbulb for 24 h b To operate an electric oven for 4 6 h if it carries a current of 20 0 A at 220 V tA

In a particular area of the country electrical energy costs 0 17 per kilowatt hour Round your answers in dollars to at least two decimal places a How much does it cost to operate an old style incandescent 40 0 W light bulb continuously for 24 hours b A modern LED light bulb that emits as much visible light as a 40 0 W incandescent only draws 4 50 W of power How much does it cost to operate this bulb for 24 hours c A particular electric oven requires a potential difference of 220 V and draws 20 0 A of current when operating How much does it cost to operate the oven for 4 80 hours

The figure below shows a battery connected to a circult The potential difference across the battery and the R 3 40 0 and V 5 00 V www www 5 000 www 0 4 00 2 www 3 00 f www a What is the equivalent resistance in 0 of R and the 5 000 resistor b Using the result from part a what is the equivalent resistance in 0 of R the 5 000 resistor and the 4 000 resistor c Using the result from part b what is the equivalent resistance in 0 of R the 5 000 resistor the 4 000 resistor and the 3 000 resistor d using the result from part c what is the equivalent resistance in 0 of the entire circuit Q e What is the current in A through the battery equivalently the conventional current that exits the positive terminal of the battery and enters the R A 1 What is the magnitude of the potential difference in V across R V 9 Using the result from part f and the battery s potential difference what is the magnitude of the potential difference in V across the 3 000 resistor V h What is the current in A in the 3 000 resistor

2 Adding resistors or light bulbs in series increases the total resistance and limits the current flowing through the circuit Voltage drops vary depending on the magnitude of the resistor a If your source were 6V how much voltage drop would occur across the 50 bulb compared to the voltage drop across the 10 2 resistor b If there were six 10 resistors attached in series to the 6 V source i How much voltage drop would occur across each resistor ii What is the equivalent resistance of the six 10 22 resistors in series

speed in radians per second of the rotating generator at the electrical plant and t is the time measured in seconds It is essential for electric generators to rotate at precisely 60 cycles per sec Complete parts a and b a How many times does the current oscillate in 0 40 sec 24 time s b What are the maximum and minimum voltages in this outlet Is the voltage always equal to 115 volts The maximum voltage is 163 V and the minimum voltage is 163 V s the voltage always equal to 115 volts Yes C

Common household electric current is called alternating current because the current alternates direction within the wires The voltage V in a typical 115 volt outlet can be expressed by the function V t 163 sin ot where is the angular speed in radians per second of the rotating generator at the electrical plant and t is the time measured in seconds It is essential for electric generators to rotate at precisely 60 cycles per sec Complete parts a and b a How many times does the current oscillate in 0 40 sec 24 time s b What are the maximum and minimum voltages in this outlet Is the voltage always equal to 115 volts The maximum voltage is 163 V and the minimum voltage is 163 V Is the voltage always equal to 115 volts OYes O No

Four resistors are arranged in a circuit as shown There is a constant voltage Vacross the voltage source The current is 0 25 ampere a Find the equivalent resistance of the four resistors 5 Find the voltage Vacross the voltage source Find the voltage across resistor R Find the power dissipated by resistor R I R 16 Q2 R 60 52 R 120

For the circuit of Fig 5 75 a Employ Norton s theorem to reduce the network connected to RL to only two components b Calculate the downward directed current flowing through RL if it is a 3 3 k resistor c Verify your answer by simulating both circuits with PSpice or a comparable CAD tool 300 mA O 5 kft 7 kn I kn 2 5 V 6 kn

The resistance of a wire is 10 2 Its length is increased by 10 by stretching The new resistance will now be a 1 20 b 12 220 c 13 d 122 2 2 WIL

7 The current in a conductor varies with time t as 1 21 31 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 a 10 C b 24 C c 33 C The positive temperature coefficient of resistance is for 8 d 44 C

When a galvanometer is shunted by 5 2 resistance deflection is reduced to 1 6th of the riginal value of galvanometer is further with a resistance of 1 2 deflection as measured from riginal value will be reduced by A C reduced by 20 31 B D reduced by reduced by

72 n identical capacitors in series are connected battery and at steady state the total energy st parallel across same source the total energy wo by the assembly is w1 If they had been connecter e have been w2 Then 1 1 n 3 n 1 W equals 2 1 n2 4 n2 1

has resistance R is given as a V E R r fetV E 1 r R high d Only the 10 If E is the emf of a cell of internal external resistance R then potential difference act b V E d V E 1 R r Two non ideal batteries are connected in series the following statements

57 The transfer ratio of a transistor is 50 The input resistance of the transistor when used in common emitter configuration is 1000 22 For an a c input voltage of 0 01 V the value of the collector a c current is a 250 A c 750 A b 500 A d 900 A

The resistance between P and Q in the given figure is wwwww A wwwww Only one correct answer www

nr R 7 The maximum power dissipated in an external resistance R when connected to a cell of emf E and internal resistance r will be E E E a b 2r 3r Distance across A and B in the figure below r c d E 4r 23