Current through the \(2~\Omega\)$$ resistance in the electrical network shown is:

For the circuit shown in the figure, the current \(I\) will be:

1. \(0.75~\text{A}\)
2. \(1~\text{A}\) 
3. \(1.5~\text{A}\)
4. \(0.5~\text{A}\)

A current of 2 A is to be sent through a resistor of \(5 ~\Omega.\) Number of cells required in series, if each has emf 2 V and internal resistance 0.5 $\mathrm{\Omega }$, are:
1. 40
2. 30
3. 20
4. 10

Two batteries, one of emf \(18\) volts and internal resistance \(2~\Omega\) and the other of emf \(12\) V and internal resistance \(1~\Omega,\) are connected as shown. The voltmeter \(\mathrm{V}\) will record a reading of: 

1. \(18\) V
2. \(30\) V
3. \(14\) V
4. \(15\) V

Two batteries, one of emf 18V and internal resistance 2 $\mathrm{\Omega }$ and the other of emf 12 V and internal resistance 1 $\mathrm{\Omega ,}$ are connected as shown. Reading of the voltmeter is:
(if voltmeter is ideal)

1.  14 V

2.  15 V

3.  18 V

4.  30 V

A battery consists of a variable number \('n'\) of identical cells having internal resistances connected in series. The terminals of battery are short circuited and the current \(i\) is measured. The graph below that shows the relationship between \(i\) and \(n\) is:

1.		2.
3.		4.

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

Two cells of e.m.f. E and internal resistance r₁ and r₂ are connected in series through an external resistance R. The value of R for which the potential difference across one of the cells becomes zero will be:

1.  $\frac{{\mathrm{r}}_1{\mathrm{r}}_2}{{\mathrm{r}}_1 + {\mathrm{r}}_2}$ 

2.  ${\mathrm{r}}_1+{\mathrm{r}}_2$

3.  $\left|{\mathrm{r}}_2 - {\mathrm{r}}_1\right|$

4.  $\frac{{\mathrm{r}}_1}{{\mathrm{r}}_2}$

In the circuit shown below, E₁ = 4.0 V, R₁= 2 Ω, E₂ = 6.0 V, R₂ = 4 Ω and R₃ = 2 Ω. The current I₁ is:

1. 1.6 A

2. 1.8 A

3. 1.25 A

4. 1.0 A

12 cells each having the same emf are connected in series with some cells wrongly connected. The arrangement is connected in series with an ammeter and two similar cells which are in series. Current is 3 A when cells and battery aid each other and is 2 A when cells and battery oppose each other. The number of cells wrongly connected is/are:

1. 4

2. 1

3. 3

4. 2