Three resistors \(2~\Omega, 4~\Omega\)
1. \(10~\text A\)
2. \(17~\text A\)
3. \(13~\text A\)
4. \(19~\text A\)
At room temperature \((27~^\circ \text{C})\) the resistance of a heating element is \(100~\Omega.\) What is the temperature of the element if the resistance is found to be \(117~\Omega?\)
(Given that the temperature coefficient of the material of the resistor is \(1.70\times 10^{-4}~^{\circ}\text{C}^{-1}\))
1. \(1027~^{\circ}\text{C}\)
2. \(1007~^{\circ}\text{C}\)
3. \(1020~^{\circ}\text{C}\)
4. \(1127~^{\circ}\text{C}\)
A negligibly small current is passed through a wire of length \(15~\text{m}\) and uniform cross-section \(6.0\times10^{-7}~\text{m}^2,\) and its resistance is measured to be \(5.0~\Omega.\) What is the resistivity of the material at the temperature of the experiment?
1. | \(1\times 10^{-7}~\Omega\text{m}\) | 2. | \(2\times 10^{-7}~\Omega\text{m}\) |
3. | \(3\times 10^{-7}~\Omega\text{m}\) | 4. | \(1.6\times 10^{-7}~\Omega\text{m}\) |
A silver wire has a resistance of \(2.1~\Omega\) at \(27.5^\circ \text{C},\) and a resistance of \(2.7~\Omega\) at \(100^\circ \text{C}.\) The temperature coefficient of resistivity of silver is:
1. \(0.0033^\circ \text{C}^{-1}\)
2. \(0.039^\circ \text{C}^{-1}\)
3. \(0.0039^\circ \text{C}^{-1}\)
4. \(0.033^\circ \text{C}^{-1}\)
The current drawn from a \(12~\text{V}\) supply with internal resistance \(0.5~\Omega\) by the infinite network (shown in the figure) is:
1. \(3.12~\text{A}\)
2. \(3.72~\text{A}\)
3. \(2.29~\text{A}\)
4. \(2.37~\text{A}\)
Figure shows a potentiometer with a cell of 2.0 V and internal resistance 0.40 Ω maintaining a potential drop across the resistor wire AB. A standard cell which maintains a constant emf of 1.02 V (for very moderate currents up to a few mA) gives a balance point at 67.3 cm length of the wire. To ensure very low currents drawn from the standard cell, a very high resistance of 600 kΩ is put in series with it, which is shorted close to the balance point. The standard cell is then replaced by a cell of unknown emf ε and the balance point found similarly, turns out to be at 82.3 cm length of the wire. The value of ε is:
1. 1.33 V
2. 1.50 V
3. 1.24 V
4. 1.07 V
Figure shows a potentiometer circuit for comparison of two resistances. The balance point with a standard resistor R=10.0 Ω is found to be 58.3 cm, while that with the unknown resistance X is 68.5 cm. The value of X is:
1.
2.
3.
4.
The figure shows a 2.0 V potentiometer used for the determination of the internal resistance of a 1.5 V cell. The balance point of the cell in the open circuit is 76.3 cm. When a resistor of 9.5 Ω is used in the external circuit of the cell, the balance point shifts to 64.8 cm length of the potentiometer wire. The internal resistance of the cell is:
1. \(1.68~\Omega \)
2. \(0.13~\Omega \)
3. \(0.31~\Omega \)
4. \(1.12~\Omega \)
A potential difference of 10 V is applied across a conductor of . The number of electrons flowing through the conductor in 300 sec is:
1.
2.
3.
4.