B Two resistances are connected in the two gaps of a meter bridge. The balance point is 25 ctn from the
zero end. A resistance of 1022 is connected in series with the smaller of the two resistances when the
null point shifts to 50cm. The smaller of the two resistances has the value
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PLEASE ANSWER THIS QUESTION IT'S URGENT
Answers
Answer:
Value of resistance = 5 Ω
Explanation:
Given:
When two resistances are connected in the two gaps of a metre bridge, the balance point is 25 cm from the zero end.
When a resistance of 10 Ω is connected in series, the smaller of the two resistances the null point shifts to 50 cm.
To Find:
The value of the smaller resistance
Solution:
Metre bridge works on the principle of Wheatstone bridge.
It is a bridge of network of four resistors. When the galvanometer shows zero deflection, that is when no current flows through the galvanometer, the bridge is said to be balanced.
In a metre bridge,
Q
P
=
100−l
l
where P is the unknown resistance and l is the balance point.
According to the given question,
Q
P
=
100−25
25
Q
P
=
75
25
=
3
1
Q = 3P -----(1)
According to the second case given,
When a resistance of 10 Ω is added to the smaller of the two resistances, the null points shifts to 50 cm.
Let us assume that P is the resistance with the lower value,
Hence,
Q
P+10
=
100−50
50
Q
P+10
=
50
50
=1
Q = P + 10 ----(2)
From equations 1 and 2,
3P = P + 10
2P = 10
P = 5 Ω
Hence the value of the smaller of the two resistances is 5 Ω.
B Two resistances are connected in the two gaps of a meter bridge. The balance point is 25 ctn from the
zero end. A resistance of 1022 is connected in series with the smaller of the two resistances when the
null point shifts to 50cm. The smaller of the two resistances has the value
Value of resistance = 5 Ω
Explanation:
Given:
When two resistances are connected in the two gaps of a metre bridge, the balance point is 25 cm from the zero end.
When a resistance of 10 Ω is connected in series, the smaller of the two resistances the null point shifts to 50 cm.
To Find:
The value of the smaller resistance
Solution:
Metre bridge works on the principle of Wheatstone bridge.
It is a bridge of network of four resistors. When the galvanometer shows zero deflection, that is when no current flows through the galvanometer, the bridge is said to be balanced.
In a metre bridge,
where P is the unknown resistance and l is the balance point.
According to the given question,
Q = 3P -----(1)
According to the second case given,
When a resistance of 10 Ω is added to the smaller of the two resistances, the null points shifts to 50 cm.
Let us assume that P is the resistance with the lower value,
Hence,
Q = P + 10 ----(2)
From equations 1 and 2,
3P = P + 10
2P = 10
P = 5 Ω
Hence the value of the smaller of the two resistances is 5 Ω.