On interchanging the resistances, the balance point of a meter bridge shifts to the left by 10 cm . The resistance of their series combination is 1 kΩ . How much was the resistance on the left slot before interchanging the resistances?

Step-by-step solution

a b = l 100 - l           a + b = 1000 b a = l − 10 110 − l 100 − l l = l − 10 110 − l l 2 − 10 l = 11000 + l 2 − 100   l = 110   l 200 l = 11000 l = 110 2 = 55 55 45 = a b ⇒ a = 550   Ω           b = 450   Ω