Question

LEUT23
19. Potentiometer wire length is 10 m, having a total
resistance of 10 12. If a battery of emf 2 volts
(of negligible internal resistance) and a rheostat
are connected to it then the potential gradient
is 20 mV/m; find the resistance imparted
through the rheostat :-
(1) 90
(2) 990
(3) 40
(4) 190
​

Answer 1

Answer:

2) 990..................

Explanation:

........

Answer 2

Explanation:

K=20mV/m

V=K.L

V=20×10=200

I=V/R=

10

200

=20A

I=

R+R

1

E

=

10+R

1

2

,20=

10+R

2

2

R

1

=

10

99

Ω