If the potential difference across ends of a metallic wire is doubled, the drift velocity of charge carriers will become:
1. double 
2. half
3. four times
4. one-fourth 

Potentiometer wire is replaced by another wire of the same material and same length but half the radius. For a given potential difference, sensitivity of the potentiometer:

1.  decreases.

2.  increases.

3.  remains the same.

4.  may increase or decrease.

The resistance between terminals A and B is:

1.  5 $\Omega$

2.  15 $\Omega$

3.  10 $\Omega$

4.  20 $\Omega$

What is the ratio of currents flowing in the resistors x and y of resistance 10 $\mathrm{\Omega }$ each?
                     
1.  1

2.  0.5

3.  1.5

4.  2.0

What is the equivalent resistance between points a and b, if the value of each resistance is R?

What is the value of current I in the network shown below?

A current passes through a wire of variable cross-section in steady-state as shown. Then incorrect statement is:

The value of E (emf of the cell) in the circuit given below is:
  

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 given circuit diagram, 3 identical bulbs are connected. If bulb B₃ get fused suddenly, how will the brightness of bulbs B₁ and B₂ change?