Physics
Current Electricity and Circuits
377 Questions
Current electricity and circuits questions cover resistors, EMF, internal resistance, and power calculations in series and parallel configurations. Solving these builds a strong understanding of electrical principles and circuit analysis. These physics problems are highly relevant for technical and science aptitude tests.
Resistor combinationsPower dissipationEMF and internal resistanceAC circuit analysisOperational amplifiers
Current Electricity and Circuits Questions
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7536 ohm
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2400 ohm
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62.8 m ohm
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753.6 k ohm
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7536 micro ohm
A
Correct answer
Explanation
XL = 2*pi*f*L
so, 2*3.14*120 k*10 m = 7536ohm
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inductance
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reactance
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impedance
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conductance
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capacitance
C
Correct answer
Explanation
Combination of resistance and capacitance gives impedance i.e. R+jXc. R is real part. Xc is imaginary part, which is combination of impedance.
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32 W
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200 W
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32 MW
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0.0008 W
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1250 W
A
Correct answer
Explanation
V = IR, P = VI, P = I*I*R, P = 400 10-3 400 * 10-3200 = 32 10-6 * 106,mili is converted into 10-3 and micro converted into10-6. Therefore, answer is = 32 W
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7.5 V
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11.95 V
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4.5 V
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16.5 V
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12.05 V
A
Correct answer
Explanation
V = E - Ir Now,
E = 12 V, I = 90 Ar = 5 x 10 -2 ΩV = 12 - 90 x 5 x 10 -2 = 7.5 V
V = 12 - 4.5 = 7.5 V
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24 k ohm
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24 micro ohm
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6000 micro ohm
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41.66 micro ohm
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41.66 ohm
A
Correct answer
Explanation
Ohms law R = V/ I,
so R = 12/ 500 micro = 24 k ohm
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30 A
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0.033 A
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48 A
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4.8 A
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0.33 A
A
Correct answer
Explanation
According to Ohm’s law
E = Ir
I = E/r = 12/0.4 = 30 A
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28.8 ohm
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7200 k ohm
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0.034 ohm
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4.166 ohm
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0.24 ohm
A
Correct answer
Explanation
V = 120 V
P = 500 W
Find: R
Use the P = V2 / R equation to calculate the resistance: R = V2 / P = (120 V)2 / (500 W)
R = 28.8 ohm
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5 ohm
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2 ohm
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17 ohm
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0.05 ohm
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20 ohm
C
Correct answer
Explanation
The relation for current using Ohm’s law is I = E / R + r
R + r = E / I = 10 / 0.5
R + r = 20 ohm
R = 20 - 3
R = 17 ohm
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2 × 10−7 Ω.m
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450 × 10−7 Ω.m
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0.5 × 10−7 Ω.m
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0.5 × 107 Ω.m
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18 × 107 Ω.m
A
Correct answer
Explanation
R = ρL/A
ρ = R A / L
= 5 x 6.0×10−7 / 15
= 2 ×10−7 Ω.m
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LDR
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Strain guage
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Thermistor
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Preset
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VDR
C
Correct answer
Explanation
A thermistor is a type of resistor whose resistance varies significantly with temperature, more so than in standard resistors.
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0.5 ohm
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0.055 ohm
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0.11 ohm
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18 ohm
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9 ohm
A
Correct answer
Explanation
Resistance between any two corners
=R,
and
1/R =1/3+1/(3+3)
=1/3 + 1/6 =9/18
R =1/2 =0.5 ohm
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0.50 Ampere
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2 Ampere
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800 Ampere
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4 m Ampere
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1 m Ampere
A
Correct answer
Explanation
I = Q / t = 20 / 40 = 0.5 Ampere
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9.375 × 1019
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1440 × 10-19 electrons
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5.625 × 1021
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0.106 × 10-19 electrons
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24 × 10-19 electrons
C
Correct answer
Explanation
A single electron charge is q = 1.6 × 10-19C
If N electrons pass through the conductor, the total charge transferred: ∆Q = N×q.
If the time needed for the charge to pass through is ∆t,
then the current is:I =∆Q/∆t = N×q/∆t;
From this, the number of electrons: N = I×∆t/q.
∆t = 3 min. = 3×60 s = 180 s.
N = 5 A×180s/ 1.6×10-19C = 5.625×1021electrons
Answer: N = 5.625×1021electrons
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resistance
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capacitance
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inductance
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rectification
C
Correct answer
Explanation
The ability to resist the variation of electric current is known as inductance. Because of the basic property of the inductor, it opposes the sudden change in current. If it doesn't oppose the current, then the voltage across the inductor should be infinite which is practicaly not possible with any finite source.
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0.166 amp
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0.434 amp
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230 amp
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330 amp
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0.68 amp
E
Correct answer
Explanation
Number of cells in a row n = 10
Number of such rows m = 5
i = nE/(R + nr/m) = 10 x 1.5/(20 + 10 x 1/5) = 15/22 = 0.68 amp