Electrical Engineering - Ohm's Law - Discussion

Discussion :: Ohm's Law - General Questions (Q.No.14)

14. 

If you wish to increase the amount of current in a resistor from 120 mA to 160 mA by changing the 24 V source, what should the new voltage setting be?

[A]. 8 V
[B]. 320 V
[C]. 3.2 V
[D]. 32 V

Answer: Option D

Explanation:

No answer description available for this question.

Ajith128 said: (Jan 5, 2011)  
No need to go for calculation 4 like these maths. We know only option to increase current in a give circuit increase voltage. So to increase current voltage must be increased. All other values are less the 24 and only 32 and 320 are higher.

Raghu said: (Mar 3, 2011)  
For 1v 5ma changed so like that 40 ma changes means 8 v changes.

So to add that 24+8=32v for 160A

Mani said: (Mar 13, 2011)  
1ST INCREASING THE AMOUNT OF CURRENT FROM 120mA THEN CHANGING THE VOLTAGE FROM 24V.. K SO, R=V/I R=24/120 R=0.2K.O ... NOW WE R FIND RESISTOR VALUE... NOW WE WANT NEW VOLTAGE SETTING... SO,PUT THE RESISTOR VALUE IN OHMS LAW... ALREADY WE HAVE mA VALUE.. SO, V=I*R V=160*0.2 "V=32V "...

Pooms said: (May 19, 2011)  
Thank you Mr.Mani...... I'm very clear....

Nikul Prajapati said: (May 25, 2011)  
With help of maths therasuit

120mA - 24V

Then 160mA - (?) (How Much)

Means 160*24/120 = 32V

Sibananda Chakra said: (Jul 6, 2011)  
Thank you all of you. I am very clear.

Prashant said: (Jul 28, 2011)  
Nice calculation of nikul.

Santhosh said: (Aug 30, 2011)  
Hi nikul which formula you are using to solve this, may I know the name of the formula.

Nagnaga said: (Sep 16, 2011)  
Hi santosh its obviously ohms law, since we are doing problems under ohms law subtitle.

Ashutosh Sharma said: (Jun 18, 2012)  
V1/I1 = V2/I2.

24/120 = V2/160.

V2 = 32Volt.

Vinay Babu said: (Oct 11, 2012)  
V is directly proportional to I (i.e) go with @Ashutosh is very smart.

Raju Giri said: (Feb 24, 2014)  
Here is two currents rating then we apply ohms for two voltage rating like V1/I1 = V2/I2 So,

24/120 =V2 /160,
8/1 = V2/4,
V2= 32 Volt.

Ananda Kumar said: (Mar 6, 2014)  
They given 2 I ratings and V1 rating and asked to find the v2 value.
R = V/I.

V1/I1 = 24/120 = 8=R2.....For V1--------1.
V2/I2 = v2/160 = V2/4 = R2..For V2--------2.

Equate 2 Epns,
8 = V2/4
V2 = 32 volts.

Jaswinder Singh said: (Aug 14, 2014)  
V = IR.
TAKE RATIO V1/I1 = V2/I2.
V2 = (V1*I2)/I1.
V2 = (24*160)/120.
V2 = (3840)/120.
V2 = 32V is answer.

Golam Mahmud said: (May 9, 2015)  
v1/v2 = I1/I2.

So v2 = 32V.

Atirrh said: (Jul 12, 2015)  
I = 120mA (1mA = 1000 A).
I = 120*1000 A or 12*10000 A.
V = 24v.
R = ?

According to ohm's law (V = IR).

R = V/I.
R = 24/12*10000.

Again,

I = 160*1000A or 16*10000.
R = 24/12*10000.
V = ?

According to ohm's law (V = IR).

V = 16*10000*24/12*10000.
V = 32v.

Atirrh said: (Jul 12, 2015)  
I = 120 ma to 160 ma.

How many times it increase?

I = 160/120.
I = 4/3 times.
V = 24*4/3.
V = 32 v.

Atirrh said: (Jul 19, 2015)  
I = 120 mA (1 mA = 1/1000 A).
I = 120*1/1000 A or 12/100 A.

V = 24 v.
R = ?

According to ohm's law (V = IR).

R = V/I.
R = 24/12/100.
R = 200.

Again,

I = 160*1/1000 A or 16/100.
R = 200.
V = ?

According to ohm's law (V = IR).

V = 16/100*200.
V = 32 v.

Dm Matsaba said: (May 18, 2016)  
Thank you all for giving different methods to get the answer.

M.Srav said: (Jul 7, 2016)  
Thank you all for giving me an idea.

Sachin said: (Aug 19, 2016)  
Thank you @Ashutosh Sharma.

Sunil said: (Sep 12, 2016)  
120 : 160 : 24 : x.
x = 160 * 24/120,
x = 32.

Sridhar said: (Sep 21, 2016)  
Just apply the formula V1/I1 = V2/I2 then we will get the answer.

Suri said: (Nov 6, 2016)  
Logically you are right @Raghu.

Abdi Sadick said: (Apr 2, 2017)  
Thanks for all your calculation. I get it now.

Shahid Ansari said: (Jun 14, 2017)  
Good trick, thank you @Ashutosh Sharma.

Krunal Soni said: (Jun 17, 2017)  
Nice trick, Thaks @Ashutosh.

Chuki said: (Jul 1, 2018)  
Change 120mA to 0.12A.

Then solve for R. R = (24/0.12) = 200 ohms.

So, it would be R = 200 ohms, I = 0.16A. V = IR = (0.16)(200) = 32 v.

Swetha said: (Aug 10, 2018)  
Ohm's law applies.

V1/V2=I1/I2.

Jake said: (Feb 13, 2019)  
Thanks @Mani.

The resistance is constant.

Vaidya Preet said: (Jul 30, 2019)  
Thank You for the explanation of the answer.

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