Calculate Current Drawing at 120V After 15.8% Voltage Reduction

  • Thread starter Thread starter shimizua
  • Start date Start date
  • Tags Tags
    Current
Click For Summary
SUMMARY

The discussion focuses on calculating the current drawn by an electrical device at 120V after a 15.8% voltage reduction. Initially, the device draws 2.56 A at 120 V with a resistance of 46.875 ohms. The correct approach involves adjusting the resistance to 85% of its original value, leading to a new resistance of 39.375 ohms. The current can then be accurately calculated using Ohm's Law, resulting in a current of approximately 3.05 A.

PREREQUISITES
  • Understanding of Ohm's Law (V = IR)
  • Basic knowledge of electrical resistance and current
  • Ability to perform percentage calculations
  • Familiarity with voltage reduction concepts
NEXT STEPS
  • Learn about Ohm's Law applications in electrical circuits
  • Study the effects of voltage reduction on current and resistance
  • Explore practical examples of resistance calculations in electrical devices
  • Investigate the implications of power loss due to voltage drops
USEFUL FOR

Electrical engineering students, technicians working with electrical devices, and anyone involved in circuit analysis and design will benefit from this discussion.

shimizua
Messages
99
Reaction score
0

Homework Statement


If the resistance of the device were reduced by 15.8 percent, what current would be drawn at 120 V?

there was a first part of this question which i have already gotten. the question was
An electrical device draws 2.56 A at 120 V. If the voltage drops by 15.8 percent, what will be the current, assuming nothing else changes? so the resistance is 46.875


Homework Equations


ok so i believe that i would just do 120/(.158x46.875)


The Attempt at a Solution


when i did this i got like 16 A and it was said to be wrong. i am confused on what i did wrong.
 
Physics news on Phys.org
Reducing by 15% means you keep 85% of the resistance. Multiply by .842, not .158.
 

Similar threads

Identical Batteries in Parallel do not Draw Same Current, Non-Ideal?
  • · Replies 7 ·
Replies
7
Views
1K
Calculate the individual voltage, current and power in series and para
  • · Replies 1 ·
Replies
1
Views
2K
Understanding example in Wikipedia entry for open circuit voltage
  • · Replies 3 ·
Replies
3
Views
2K
Voltage drop across connecting wires?
  • · Replies 3 ·
Replies
3
Views
3K
Calculating EMF and Load Resistance for a Motor
  • · Replies 11 ·
Replies
11
Views
2K
Voltage Drop in Parallel Receptacle Wiring
  • · Replies 9 ·
Replies
9
Views
2K
Finding the current and voltage for each resistor
  • · Replies 5 ·
Replies
5
Views
2K
How can stepping up and down the voltage save energy in power transmission?
  • · Replies 2 ·
Replies
2
Views
2K
Determining terminal voltage, field current,etc.
  • · Replies 4 ·
Replies
4
Views
3K
A few questions concerning voltage, current and resistance
  • · Replies 5 ·
Replies
5
Views
2K