Advertisements
Advertisements
प्रश्न
An I0m long uniform metallic wire having a resistance of 20Ω IS used as a potentiometer wire. This wire is connected in series with another resistance of 480Ω
and a battery of emf 5V having negligible internal resistance. If an unknown emf e is balanced across 6m of the potentiometer wire, calculate
1) the potential gradient across the potentiometer wire
2) the value of the unknown emf e.
Advertisements
उत्तर
`l_1 = 10 m`
R = 20 Ω
`R_1 = 480 Ω`
V = 5 V
balancing lenght = `l_2 = 6m`
1) Potential gradient = `k = V/L = 5/6 = 0.83 "V/m"`
2) `E_1/E_2 - l_1/l_2`
`5/E_2 = 10/6`
`5 xx 6 = E_2 xx 10`
`(5 xx 6)/10 = E_2`
`:. E_2 = 3V`
APPEARS IN
संबंधित प्रश्न
In potentiometer experiment, if l1 is the balancing length for e.m.f. of cell of internal resistance r and l2 is the balancing length for its terminal potential difference when shunted with resistance R then :
A cell balances against a length of 200 cm on a potentiometer wire, when it is shunted by a resistance of 8Ω. The balancing length reduces by 40 cm, when it is shunted by a resistance of 4 Ω . Calculate the balancing length when the cell is in open circuit. Also calculate the internal resistance of the cell.
In a meter bridge shown in the figure, the balance point is found to be 40 cm from end A. If a resistance of 10 Ω is connected in series with R, balance point is obtained 60 cm from A. Calculate the values of R and S.
Why is it generally preferred to obtain the balance point in the middle of the meter bridge wire?
Write the principle of working of a metre bridge
In a metre bridge, the balance point is found at a distance l1 with resistances R and S as shown in the figure.An unknown resistance X is now connected in parallel to the resistance S and the balance point is found at a distance l2. Obtain a formula for X in terms of l1, l2 and S.
In a meter bridge, the null point is found at a distance of l1 cm from A. If now a resistance of X is connected in parallel with S, the null point occurs at l2 cm. Obtain a formula for X in terms of l1, l2 and S.
The figure shows experimental set up of a meter bridge. When the two unknown resistances X and Y are inserted, the null point D is obtained 40 cm from the end A. When a resistance of 10 Ω is connected in series with X, the null point shifts by 10 cm. Find the position of the null point when the 10 Ω resistance is instead connected in series with resistance ‘Y’. Determine the values of the resistances X and Y.
Two resistances are connected in the two gaps of a meter bridge. The balance points is 20 cm from the zero end. When resistance of 15 ohm is connected in series with the smaller of the two resistances, the null point shifts to 40 cm. The smaller of the two resistances has the value (in ohm) ______.
In a meter bridge experiment, resistance are connected as shown in figure, The balancing length 1, is 55 cm. Now an unknown resistance x is connected in series with P and new balancing length is found to be 75cm. The value of x is ______.
