Electrical Engineering - Energy and Power - Discussion
Discussion Forum : Energy and Power - General Questions (Q.No. 9)
9.
A 120 
resistor must carry a maximum current of 25 mA. Its rating should be at least
resistor must carry a maximum current of 25 mA. Its rating should be at leastDiscussion:
61 comments Page 4 of 7.
Sathish said:
1 decade ago
They are not that one is RMS value its 75 mW only.
Shyam said:
1 decade ago
Current should be in RMS value. So answer will be (75/2).
Rohit kumar said:
1 decade ago
P = i^2*R.
So that,
P = 25^2*120 = 25*25*120*(10^-3) = 75mW.
But is not exist so that what right answer of that question.
So that,
P = 25^2*120 = 25*25*120*(10^-3) = 75mW.
But is not exist so that what right answer of that question.
Sweta said:
1 decade ago
P = I^2*R.
P = (Imax)^2 * R.
P = (Irms*sqrt(2))^2*R.
P = (0.025*sqrt(2))^2* 120.
P = (0.035355)^2 *120.
P = 150mW.
P = (Imax)^2 * R.
P = (Irms*sqrt(2))^2*R.
P = (0.025*sqrt(2))^2* 120.
P = (0.035355)^2 *120.
P = 150mW.
(1)
R n trimukhe said:
1 decade ago
Simply go through ohms law,
V = IR.
V = 25*10-3*120.
V = 3 v.
P=VI.
P=3*25*10-3.
P=75 mWatt.
V = IR.
V = 25*10-3*120.
V = 3 v.
P=VI.
P=3*25*10-3.
P=75 mWatt.
Rabi Sankar Samanta said:
1 decade ago
p = I2R (25mA=0.025A).
P = 0.025*0.025*120.
P = 0.075W.
P = 75 mW.
Answer did not maching.
P = 0.025*0.025*120.
P = 0.075W.
P = 75 mW.
Answer did not maching.
Biswa Bhusan Pradhan said:
1 decade ago
I think the answer is 75 mW but it is not in d option.
I2R= 0.025*0.025*120 = 75 mW.
I2R= 0.025*0.025*120 = 75 mW.
Mohammed Irshad said:
1 decade ago
Option B is correct.
Explanation:
Rating current value = Irms value.
Maximum current value = Imax value.
Imax = Irms/sqrt(2).
P = Irms^2*R.
= (sqrt(2)*Imax)^2*R.
= 150mA.
Explanation:
Rating current value = Irms value.
Maximum current value = Imax value.
Imax = Irms/sqrt(2).
P = Irms^2*R.
= (sqrt(2)*Imax)^2*R.
= 150mA.
Soumen said:
1 decade ago
P=I^2*R is correct when current passing through it is given but they have given maximum current we known P=VI we known I 25ma. So the answer should be in multiples of 25.
THE MAN said:
1 decade ago
Rating of any device is such that it should carry current up to twice of the capacity. May be this reason so answer is doubled.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers