In the circuit shown below, \(E_1 = 4.0~\text{V}\), \(R_1 = 2~\Omega\), \(E_2 = 6.0~\text{V}\), \(R_2 = 4~\Omega\) and \(R_3 = 2~\Omega\). The current \(I_1\) is:
1. \(1.6\) A
2. \(1.8\) A
3. \(1.25\) A
4. \(1.0\) A
The potential difference across \(8\) ohms resistance is \(48\) volts as shown in the figure below. The value of potential difference across \(X\) and \(Y\) points will be:
1. \(160\) volt
2. \(128\) volt
3. \(80\) volt
4. \(62\) volt
Two resistances R1 and R2 are made of different materials. The temperature coefficient of the material of R1 is α and of the material of R2 is –β. The resistance of the series combination of R1 and R2 will not change with temperature, if R1/ R2 equals :
(1)
(2)
(3)
(4)
An ionization chamber with parallel conducting plates as anode and cathode has electrons and the same number of singly-charged positive ions per cm3. The electrons are moving at 0.4 m/s. The current density from anode to cathode is . The velocity of positive ions moving towards cathode is :
(1) 0.4 m/s
(2) 16 m/s
(3) Zero
(4) 0.1 m/s
A wire of resistance 10 Ω is bent to form a circle. P and Q are points on the circumference of the circle dividing it into a quadrant and are connected to a Battery of 3 V and internal resistance 1 Ω as shown in the figure. The currents in the two parts of the circle are
(1)
(2)
(3)
(4)
In the given circuit, it is observed that the current I is independent of the value of the resistance R6. Then the resistance values must satisfy
(1)
(2)
(3)
(4)
In the given circuit, with a steady current, the potential drop across the capacitor must be :
(1) V
(2) V / 2
(3) V / 3
(4) 2V / 3
A wire of length L and 3 identical cells of negligible internal resistances are connected in series. Due to current, the temperature of the wire is raised by ΔT in a time t. A number N of similar cells is now connected in series with a wire of the same material and cross–section but of length 2 L. The temperature of the wire is raised by the same amount ΔT in the same time t. The value of N is-
(1) 4
(2) 6
(3) 8
(4) 9
What is the equivalent resistance between terminals \(A\) and \(B\) of the network?
1. | \(\dfrac{57}{7}~\Omega\) | 2. | \(8~\Omega\) |
3. | \(6~\Omega\) | 4. | \(\dfrac{57}{5}~\Omega\) |
The effective resistance between points \(P\) and \(Q\) of the electrical circuit shown in the figure is:
1. | \(\frac{2 R r}{\left(R + r \right)}\) | 2. | \(\frac{8R\left(R + r\right)}{\left( 3 R + r\right)}\) |
3. | \(2r+4R\) | 4. | \(\frac{5R}{2}+2r\) |