In the circuit shown here, what is the value of the unknown resistor R so that the total resistance of the circuit between points P and Q is also equal to R 

1. 3 ohms

2. $\sqrt{39}ohms$

3. $\sqrt{69}ohms$

4. 10 ohms

Find the equivalent resistance between the points a and b 

1. 2 Ω

2. 4 Ω

3. 8 Ω

4. 16 Ω

The potential difference between points A and B is:

         
1. 207 V
2. 407 V
3. 107 V
4. 0

In the circuit shown in the figure, the current flowing in 2 Ω resistance 

1. 1.4 A

2. 1.2 A

3. 0.4 A

4. 1.0 A

In the figure given the value of X resistance will be, when the p.d. between B and D is zero 

1. 4 ohm

2. 6 ohm

3. 8 ohm

4. 9 ohm