Advertisements
Advertisements
Question
A potentiometer wire has a length of 4 m and resistance of 20 Ω. It is connected in series with resistance of 2980 Ω and a cell of emf 4 V. Calculate the potential along the wire.
Advertisements
Solution
Given data:
l = 4m of R = 20Ω
In series with R’ = 2980Ω
E = 4 V
Since 20 is in series with 2980
Reff = 20 + 2980 = 3000
current I = `"V"/"R"_"eff" = 4/3000 = 1.3 xx 10^-3 "A"`
I = `1.3 xx 10^-3`A
Potential along the wire of 4 m length is,
`"V"/"l" - "IR"/"l" = (1.3 xx 10^-3 xx 20)/4`
`= (26 xx 10^-3)/4`
= 6.5 × 10-3 Vm-1
`"V"/"l" = 6.5 xx 10^-2 "Vm"^-1`
Potential = `0.65 xx 10^-2 "Vm"^-1`
APPEARS IN
RELATED QUESTIONS
State Kirchhoff's rules and explain on what basis they are justified.
In the given circuit, assuming point A to be at zero potential, use Kirchhoff’s rules to determine the potential at point B.
Find the equivalent resistances of the networks shown in the figure between the points a and b.
On which conservation principle is Kirchoff's Second Law of electrical networks based?
Figure shows current in a part of an electrical circuit. Then current I is ______.
Assertion: Kirchhoff’s junction rule follows from conservation of charge.
Reason: Kirchhoff’s loop rule follows from conservation of momentum.
Kirchhoff s second law is based on the law of conservation of ______
Three resistors having resistances r1, r2 and r3 are connected as shown in the given circuit. The ratio `i_3/i_1` of currents in terms of resistances used in the circuit is:
In a meter bridge the point D is a neutral point (Figure).
- The meter bridge can have no other neutral point for this set of resistances.
- When the jockey contacts a point on meter wire left of D, current flows to B from the wire.
- When the jockey contacts a point on the meter wire to the right of D, current flows from B to the wire through galvanometer.
- When R is increased, the neutral point shifts to left.
A 6-volt battery is connected to the terminals of a three-metre-long wire of uniform thickness and resistance of 100 ohms. The difference of potential between two points on the wire separated by a distance of 50 cm will be ______.
