Free Resistance and Resistivity MCQs with Answers
86 Resistance and Resistivity MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Resistance measures opposition to current in a conductor and follows R = V/I for an ohmic conductor, while resistivity is an intrinsic property of the material. Questions use R = ρL/A, examine effects of length, cross-sectional area and temperature, and distinguish resistance, resistivity, conductance and conductivity.
Last updated
86 questions · page 1 of 5
- A. proportional to its length and to its cross sectional area
- B. proportional to its length and inversely proportional to its cross sectional area
- C. independent of its dimensions
- D. inversely proportional to its length
Explanation: R equals rho L over A, so a longer wire offers more resistance and a thicker one less, which is why thick cables are used for heavy…
Correct answer: proportional to its length and inversely proportional to its cross sectional area- A. double
- B. half
- C. four times
- D. unchanged
Explanation: Constant volume means doubling the length halves the cross sectional area, and since resistance is proportional to length over area, the…
Correct answer: four times- A. ohm
- B. ohm metre
- C. ohm per metre
- D. volt per ampere
Explanation: Rearranging R equals rho L over A gives rho equal to RA over L, whose units are ohm times metre squared divided by metre, that is ohm…
Correct answer: ohm metre- A. 10 ohms
- B. 0.97 ohms
- C. 1.03 ohms
- D. 30 ohms
Explanation: Series resistances simply add, giving 10 ohms, and the same current passes through each while the voltages divide in proportion to the…
Correct answer: 10 ohms- A. 12 ohms
- B. 6 ohms
- C. 3 ohms
- D. 0.33 ohms
Explanation: For two equal resistors in parallel the result is simply half of one of them, so 3 ohms.
Correct answer: 3 ohms- A. Impedance
- B. Conductivity
- C. Admittance
- D. Reactance
Explanation: Conductivity measures how readily a material carries current and is the reciprocal of resistivity, with units of siemens per metre.
Correct answer: Conductivity- A. Quarter
- B. Half
- C. Zero
- D. 4 times
Explanation: Resistance is proportional to length for a given cross section and material, so quadrupling the length quadruples the resistance.
Correct answer: 4 times- A. Become zero
- B. Is halved
- C. Is doubled
- D. )D. remains same
Explanation: Resistivity is a property of the material and depends mainly on its nature and temperature, not on the wire's length or cross-sectional…
Correct answer: )D. remains same- A. 1 S
- B. 1.5 S
- C. 2 S
- D. 5 S
Explanation: Conductance is the reciprocal of resistance: G = 1/R = 1/(0.5 ohm) = 2 S.
Correct answer: 2 S- A. Resistance
- B. Voltage
- C. Current
- D. None of these
Explanation: The ohm (Ω) is the SI unit of electrical resistance, defined by R = V/I, so 1 Ω = 1 V/A.
Correct answer: Resistance11. If electrical conductivity increases with the increase of temperature of a substance, then it is a:
- A. Semiconductor
- B. Conductor
- C. Insulator
- D. None of the above
Explanation: In a semiconductor, increasing temperature releases more charge carriers, so electrical conductivity increases.
Correct answer: Semiconductor- A. Gas only
- B. Liquid only
- C. Solid only
- D. All of the above
Explanation: Young's modulus is the ratio of tensile or compressive stress to the corresponding strain, and it describes the elastic deformation of…
Correct answer: Solid only- A. The resistance of each of them increases.
- B. The resistance of each of them decreases.
- C. The resistance of copper decreases and that of germanium increases.
- D. The resistance of copper increases and that of germanium decreases
Explanation: Copper is a metal, so cooling reduces lattice vibrations and decreases its resistance.
Correct answer: The resistance of copper decreases and that of germanium increases.- A. 105 ohm metre
- B. 106 ohm metre
- C. 107 ohm metre
- D. 108 ohm metre
Explanation: Insulators have very large resistivities, and the standard approximate value used in this classification is about 10^8 ohm metre, much…
Correct answer: 108 ohm metre- A. a most sensitive galvanometer is used
- B. a steady voltage cell is used
- C. the balance point is close to the middle of the wire
- D. a high resistance box is used in one of its gap
Explanation: In a slide-wire bridge, accuracy is greatest when the balance point is near the middle, because the two wire lengths and their measurement…
Correct answer: the balance point is close to the middle of the wire16. Which one of the following physical quantities does not have the dimensions of force per unit area ?
- A. Stress
- B. Strain
- C. Youngs modulus
- D. Pressure
Explanation: Stress, Young's modulus and pressure are all force per unit area, with dimensions M L^-1 T^-2.
Correct answer: Strain- A. MLT-2
- B. ML-2T-1
- C. ML-1T-2
- D. ML-T-1
Explanation: Stress = force/area. Force has dimensions M L T^-2 and area has dimensions L², so stress has dimensions M L T^-2 / L² = M L^-1 T^-2.
Correct answer: ML-1T-2- A. Rubber
- B. Steel
- C. Glass
- D. Copper
Explanation: Elasticity in this comparison is measured by Young's modulus, and steel has a much larger Young's modulus than rubber, copper or ordinary…
Correct answer: Steel- A. 100 watt
- B. 200 watt
- C. 300 watt
- D. 60 watt
Explanation: For bulbs designed for the same voltage, R = V²/P, so resistance is inversely proportional to rated power.
Correct answer: 300 watt- A. zero almost
- B. infinite almost
- C. no prediction at all
- D. may increase or decrease
Explanation: In the ideal textbook model for a metallic conductor, thermal vibrations vanish as the temperature approaches 0 K, so its resistance…
Correct answer: zero almostResistance and Resistivity MCQs: common questions
Are these Resistance and Resistivity MCQs free?
Yes. All Resistance and Resistivity MCQs from Physics are free on TestUstad, with unlimited attempts and no account needed. Nothing on this page is a sample or a trial.
How many Resistance and Resistivity MCQs are on this page?
There are 86 Resistance and Resistivity MCQs in the Physics bank, shown 20 to a page with the correct answer and an explanation on each.
Does every Resistance and Resistivity MCQ have an explanation?
Yes. Each Resistance and Resistivity question shows the correct option and a written explanation of why it is correct, so a wrong answer teaches you something rather than just being marked wrong.
Can I take a timed Resistance and Resistivity test?
Yes. The practice button on this page starts a free Resistance and Resistivity test drawn from the Physics bank. It marks each answer instantly, gives you a score at the end, and can be retaken as many times as you like.