An ideal battery of 4 V and resistance R are connected in series in the primary circuit of a potentiometer of length 1 m and resistance 5
. The value of R, to give a potential difference of 5mV across 10 cm of potentiometer wire, is:
a.
490 
b.
480 
c.
395 
d.
495 
. The value of R, to give a potential difference of 5mV across 10 cm of potentiometer wire, is:a.
490
b.
480
c.
395
d.
495
Question ID - 50677 | SaraNextGen Top Answer An ideal battery of 4 V and resistance R are connected in series in the primary circuit of a potentiometer of length 1 m and resistance 5 . The value of R, to give a potential difference of 5mV across 10 cm of potentiometer wire, is:
a.
490
b.
480
c.
395
d.
495
An ideal battery of 4 V and resistance R are connected in series in the primary circuit of a potentiometer of length 1 m and resistance 5 . The value of R, to give a potential difference of 5mV across 10 cm of potentiometer wire, is:
|
a. |
490 |
b. |
480 |
|
c. |
395 |
d. |
495 |
1 Answer
127 votes
Answer Key / Explanation : (c) -
Let current flowing in the wire is i.
i = 
A
If resistance of 10 m length of wire is x
then x = 0.5 
= 5 
V = P.d. on wire = i. x
5 
10−3 = 
0.5)
= 10−2 or R + 5 = 400 
R = 395
127 votes
Answer Link
127