Metallic spheres A and B, having radii of 2m and 4m respectively, both possess an identical charge of 4 x 10 8C. Should these spheres be linked together via a copper wire_______________?
Show answer Hide answer
Answer: A. charge will flow from A to B
Explanation
Charge flows from the sphere with higher electrical potential to the one with lower potential until equilibrium is reached. Surface potential on a charged conducting sphere equals the charge divided by its radius, creating a potential difference between different sizes. Connecting the spheres via a copper wire provides a conductive path that equalizes surface potentials by redistributing total charge. Spherical conductor surface potential is inversely proportional to its radius for a given identical total electrostatic charge. The smaller 2-meter radius sphere possesses a higher surface potential than the larger 4-meter radius sphere holding the same charge. Charge redistribution between connected conductors always proceeds from high electric potential toward lower electric potential regions.
Stating charge will flow from A to B matches the correct potential gradient calculation between the smaller and larger spheres. Saying charge flows from B to A incorrectly assumes the larger sphere has a higher electrical potential than the smaller sphere. Claiming no flow of charge will occur ignores the unequal surface potentials caused by the different radii of the two spheres.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. A specific low-pass filter produces a maximum output of 15 V. What is its output voltage at the critical frequency_____________?
Show answer Hide answer
Answer: A. 10.60 V
At the critical frequency (cutoff frequency), the output voltage drops to 70.7% of its maximum value, which is 15 V × 0.707 ≈ 10.60 V. The critical frequency defines the exact point where filter circuit reactance equals...
Q2. Which semiconductor material is most widely used in electronics________________?
Show answer Hide answer
Answer: B. Silicon
Silicon possesses a stable crystal lattice structure and a wide bandgap making it ideal for modern manufacturing processes. It operates reliably at higher temperatures compared to alternative semiconductor materials like...
Q3. What is the maximum theoretical efficiency of a resistance-loaded class A power amplifier _________________?
Show answer Hide answer
Answer: D. 25%
The maximum theoretical efficiency of a resistively loaded class A power amplifier is 25%. Calculating the ratio of maximum undistorted AC load power to total DC supply power yields exactly one-quarter under resistive lo...
Q4. The binary value 10101 corresponds to which decimal number_________________?
Show answer Hide answer
Answer: D. 21
The binary number 10101 converts to decimal by summing the powers of two for each active bit position. Calculating sixteen plus four plus one yields the exact decimal sum of twenty-one. This positional notation system fo...
Q5. There is a restriction on the quantity of directly coupled amplifier stages because___________?
Show answer Hide answer
Answer: A. Changes in temperature cause thermal instability
Directly coupled amplifiers have no capacitors between stages, allowing DC operating voltages to pass straight through. Small temperature-induced variations in the input transistor bias current get amplified successively...
Q6. The most expensive type of coupling is _______________ coupling?
Show answer Hide answer
Answer: D. Transformer
Transformer coupling requires heavy, high-grade ferromagnetic core materials and custom copper wire windings to achieve signal transfer. Precision manufacturing of audio-frequency and radio-frequency transformers demands...