The current in a conductor varies with time t as where I is in ampere and t in seconds. The electric charge flowing through a section of the conductor during t = 2 sec to t = 3 sec is :
1. 10 C
2. 24 C
3. 33 C
4. 44 C
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.
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. | \(\frac{5R}{2}+2r\) |
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
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 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.
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. | \(\dfrac{57}{5}~\Omega\) |
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.
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
An ionization chamber with parallel conducting plates as anode and cathode has \(5\times 10^7\) electrons and the same number of singly-charged positive ions per \(\text{cm}^3.\) The electrons are moving at \(0.4~\text{m/s}.\) The current density from anode to cathode is \(4\mu \text{A/m}^2.\) The velocity of positive ions moving towards cathode is :
1. \(0.4~\text{m/s}\)
2. \(16~\text{m/s}\)
3. Zero
4. \(0.1~\text{m/s}\)