Question
The balance point in a potentiometer for a cell of emf
1.5 V is 60 cm. If a resistance of 5 Ω is connected in parallel with the cell and the new balance point shifts to 50 cm, what is the internal resistance of the cell?Solution
Let E be the emf of the cell and r be its internal resistance. In the first case, the balance point is at l ₁ = 60 cm. The potential difference across the balance point is proportional to the emf of the cell: E ∝ l ₁ E = kl ₁ , where k is the potential gradient. 1.5 = k × 60 k = 1.5/60 = 1/40 …(1) In the second case, a resistance R=5Ω is connected in parallel with the cell. The effective voltage across the potentiometer wire is now the terminal voltage V of the cell. 
The internal resistance of the cell is 1Ω.
The statutory power for exchange control was provided to RBI by the Foreign ExchangeRegulation Act (FERA) of _.
Which of the following languages has been declared as the official language of the Government of India?
When RBI decides to decrease the repo rate, money supply will _________ .
Under Prime Minister’s Employment Generation Programme (PMEGP), the subsidy for General category applicants is ___ % of the project cost in rural are...
On 16 February 2021, Ngozi Okonjo-Iweala was appointed as the seventh Director-General of the WTO. Which country does she belong to?
River Ganga does NOT pass through which of the following states?
Airbnb will invest $100mn inIndian hotel startup OYO. . Airbnb deals in Which service ?
Which of the following is not correct about Sovereign Gold Bond (SGB)?
The largest deposits of iron ore are found in the states of:
What is the name of the science that studies the past of life on earth?
Relevant for Exams:
