In the circuit shown in figure find the value of r(internal resistance of the cell) for which power transferred by the cell is maximum
1.
2.
3.
4.
A meter bridge is set up to determine unknown resistance \(x\) using a standard \(10~\Omega\) resistor. The galvanometer shows the null point when the tapping key is at a \(52\) cm mark. End corrections are \(1\) cm and \(2\) cm respectively for end \(A\) and \(B\). Then the value of \(x\) is:
1. \(10.2~\Omega\)
2. \(10.6~\Omega\)
3. \(10.8~\Omega\)
4. \(11.1~\Omega\)
The equivalent resistance of the following infinite network of resistances is
1. Less than 4 Ω
2. 4 Ω
3. More than 4 Ω but less than 12 Ω
4. 12 Ω
If each resistance in the figure is \(9~\Omega\), then the reading of the ammeter is:
1. \(5~\text{A}\)
2. \(8~\text{A}\)
3. \(2~\text{A}\)
4. \(9~\text{A}\)
The potential difference between points A and B is:
1. 207 V
2. 407 V
3. 107 V
4. 0
Five equal resistances each of resistance R are connected as shown in the figure. A battery of V volts is connected between A and B. The current flowing in AFCEB will be
1.
2.
3.
4.
Consider the circuit shown in the figure below. The current \(I_3\) is equal to:
1. \(5\) A
2. \(3\) A
3. \(-3\) A
4. \(\frac{-5}{6}\) A
Eels are able to generate current with biological cells called electroplaques. The electroplaques in an eel are arranged in 100 rows, each row stretching horizontally along the body of the fish containing 5000 electroplaques. The arrangement is suggestively shown below. Each electroplaques has an emf of 0.15 V and internal resistance of 0.25 Ω
The water surrounding the eel completes a circuit between the head and its tail. If the water surrounding it has a resistance of 500 Ω, the current an eel can produce in water is about
1. 1.5 A
2. 3.0 A
3. 15 A
4. 30 A
In the Wheatstone's bridge (shown in the figure below) \(X=Y\) and \(A>B\). The direction of the current between \(a\) and \(b\) will be:
1. | from \(a\) to \(b\). |
2. | from \(b\) to \(a\). |
3. | from \(b\) to \(a\) through \(c\). |
4. | from \(a\) to \(b\) through \(c\). |
A resistance of 4 Ω and a wire of length 5 metres and resistance 5 Ω are joined in series and connected to a cell of e.m.f. 10 V and internal resistance 1 Ω. A parallel combination of two identical cells is balanced across 300 cm of the wire. The e.m.f. E of each cell is:
1. 1.5 V
2. 3.0 V
3. 0.67 V
4. 1.33 V
When the key K is pressed at time t = 0, which of the following statements about the current I in the resistor AB of the given circuit is true?
1. I = 2 mA at all t
2. I oscillate between 1 mA and 2mA
3. I = 1 mA at all t
4. At t = 0 , I = 2 mA and with time it goes to 1 mA
In the circuit element given here, if the potential at point B, VB = 0, then the potentials of A and D are given as
1.
2.
3.
4.
As the switch S is closed in the circuit shown in the figure, the current passed through it is :
1. 4.5 A
2. 6.0 A
3. 3.0 A
4. Zero
Current through wire XY of circuit shown is :
1. 1 A
2. 4 A
3. 2 A
4. 3 A
Following figure shows cross-sections through three long conductors of the same length and material, with square cross-section of edge lengths as shown. Conductor B will fit snugly within conductor A, and conductor C will fit snugly within conductor B. Relationship between their end to end resistance is
(1) RA = RB = RC
(2) RA > RB > RC
(3) RA < RB < R
(4) Information is not sufficient
Variation of current passing through a conductor with the voltage applied across its ends varies is shown in the diagram below. If the resistance \((R)\) is determined at points \(A\), \(B\), \(C\) and \(D\), we will find that:
1. | \(R_C = R_D\) | 2. | \(R_B>R_A\) |
3. | \(R_C>R_B\) | 4. | None of these |
For a cell, the graph between the potential difference \((V)\) across the terminals of the cell and the current \((I)\) drawn from the cell is shown in the figure below. The emf and the internal resistance of the cell are, respectively:
1. | \(2~\text{V}, 0.5 ~\Omega\) | 2. | \(2~\text{V}, 0.4 ~\Omega\) |
3. | \(>2~\text{V}, 0.5 ~\Omega\) | 4. | \(>2~\text{V}, 0.4 ~\Omega\) |
In the circuit in the figure, if the potential at point A is taken to be zero, the potential at point B is :
1. -1V 2. +2V
3. -2V 4. +1V
1. | \(2:1\) | 2. | \(4:9\) |
3. | \(9:4\) | 4. | \(1:2\) |
A torch bulb rated \(4.5\) W, \(1.5\) V is connected as shown in the figure below. The emf of the cell needed to make the bulb glow at full intensity is:
1. | \(4.5\) V | 2. | \(1.5\) V |
3. | \(2.67\) V | 4. | \(13.5\) V |