All STD 12 - Current electricity questions
Newest firstShowing 51–100 of 311 questions
- 51. Equivalent resistance of the following network is _______ \(\Omega\).
2024 Hard - 52. In a metre-bridge when a resistance in the left gap is \(2\ \Omega\) and unknown resistance in the right gap, the balance length is found to be \(40\ \mathrm{cm}\). On shunting the unknown resistance with \(2\ \Omega\), the balance length changes by _______. 2024 Hard
- 53. In the following circuit, the battery has an emf of \(2\mathrm{V}\) and an internal resistance of \(\frac{2}{3}\ \Omega\). The power consumption in the entire circuit is _______ \(W\).
2024 Hard - 54. In the given circuit, the current flowing through the resistance \(20\ \Omega\) is \(0.3 \mathrm{~A}\), while the ammeter reads \(0.9 \mathrm{~A}\). The value of \(\mathrm{R}_1\) is _______ \(\Omega\).
2024 Hard - 55. In the given circuit, the current in resistance \(\mathrm{R}_3 \) is _______.
2024 Hard - 56. In the given circuit, the terminal potential difference of the cell is _______.
2024 Hard - 57. In the given figure \(R_1=10 \Omega, R_2=8 \Omega, R_3=4 \Omega\) and \(R_4=8 \Omega\). Battery is ideal with emf \(12 \mathrm{~V}\). Equivalent resistant of the circuit and current supplied by battery are _______ respectively.
2024 Hard - 58. In the given figure, the charge stored in \(6 \ \mu \mathrm{F}\) capacitor, when points \(A\) and \(B\) are joined by a connecting wire is _______ \(\mu \mathrm{C}\).
2024 Hard - 59. Resistance of a wire at \(0^{\circ} \mathrm{C}, 100^{\circ} \mathrm{C}\) and \(t^{\circ} \mathrm{C}\) is found to be \(10 \Omega, 10.2 \Omega\) and \(10.95 \Omega\) respectively. The temperature \(t\) in Kelvin scale is _______. 2024 Hard
- 60. The charge accumulated on the capacitor connected in the following circuit is________ \(\mu \mathrm{C}\) (Given \(\mathrm{C}=150\ \mu \mathrm{F}\))
2024 Hard - 61. The current flowing through the \(1 \Omega\) resistor is \(\frac{\mathrm{n}}{10} \ A.\) The value of \(n\) is _______.
2024 Hard - 62. The current in a conductor is expressed as \(I=3 t^2+4 t^3\), where \(I\) is in Ampere and \(t\) is in second. The amount of electric charge that flows through a section of the conductor during \(t=1\) s to \(t=2 \mathrm{~s}\) is _______ \(\mathrm{C}\). 2024 Hard
- 63. The effective resistance between \(A\) and \(B\), if resistance of each resistor is \(R\) will be _______.
2024 Hard - 64. The electric current through a wire varies with time as \(I=I_0+\beta t\). where \(I_0=20 \mathrm{~A}\) and \(\beta=3 \mathrm{~A} / \mathrm{s}\). The amount of electric charge crossed through a section of the wire in \(20 \mathrm{~s}\) is : 2024 Hard
- 65. The equivalent resistance between \(A\) and \(B\) is _______.
2024 Hard - 66. The number of electrons flowing per second in the filament of a \(110 \mathrm{~W}\) bulb operating at \(220 \mathrm{~V}\) is _______. (Given \(\mathrm{e}=1.6 \times 10^{-19} \mathrm{C}\) ) 2024 Hard
- 67. The ratio of heat dissipated per second through the resistance \(5 \Omega\) and \(10 \Omega\) in the circuit given below is _______.
2024 Hard - 68. The reading in the ideal voltmeter \((V)\) shown in the given circuit diagram is _______.
2024 Hard - 69. The resistance per centimeter of a meter bridge wire is \(\mathrm{r}\), with \(\mathrm{X}\ \Omega\) resistance in left gap. Balancing length from left end is at \(40 \mathrm{~cm}\) with \(25\ \Omega\) resistance in right gap. Now the wire is replaced by another wire of \(2 \mathrm{r}\) resistance per centimeter. The new balancing length for same settings will be at _______. 2024 Hard
- 70. The resistances of the platinum wire of a platinum resistance thermometer at the ice point and steam point are \(8 \Omega\) and \(10 \Omega\) respectively. After inserting in a hot bath of temperature \(400^{\circ} \mathrm{C}\), the resistance of platinum wire is _______. 2024 Hard
- 71. The value of unknown resistance \((x)\) for which the potential difference between \(B\) and \(D\) will be zero in the arrangement shown, is _______.
2024 Hard - 72. Three voltmeters, all having different internal resistances are joined as shown in figure. When some potential difference is applied across \(\mathrm{A}\) and \(B\), their readings are \(V_1, V_2\) and \(V_3\). Choose the correct option.
2024 Hard - 73. To determine the resistance (\(R\)) of a wire, a circuit is designed below, The \(V-I\) characteristic curve for this circuit is plotted for the voltmeter and the ammeter readings as shown in figure. The value of \(\mathrm{R}\) is _______\(\Omega\).
2024 Hard - 74. To measure the internal resistance of a battery, potentiometer is used. For \(\mathrm{R}=10 \Omega\), the balance point is observed at \(\ell=500 \mathrm{~cm}\) and for \(\mathrm{R}=1 \Omega\) the balance point is observed at \(\ell=400 \mathrm{~cm}\). The internal resistance of the battery is approximately _______. 2024 Hard
- 75. To measure the temperature coefficient of resistivity \(\alpha\) of a semiconductor, an electrical arrangement shown in the figure is prepared. The arm BC is made up of the semiconductor. The experiment is being conducted at \(25^{\circ} \mathrm{C}\) and resistance of the semiconductor arm is \(3 \mathrm{~m} \Omega\). Arm BC is cooled at a constant rate of \(2^{\circ} \mathrm{C} / \mathrm{s}\). If the galvanometer \(\mathrm{G}\) shows no deflection after \(10 \mathrm{~s}\), then \(\alpha\) is _______.
2024 Hard - 76. Two cells are connected in opposition as shown. Cell \(\mathrm{E}_1\) is of \(8 \mathrm{~V}\) emf and \(2 \ \Omega\) internal resistance; the cell \(E_2\) is of \(2 \mathrm{~V}\) emf and \(4\ \Omega\) internal resistance. The terminal potential difference of cell \(\mathrm{E}_2\) is _______.
2024 Hard - 77. Two conductors have the same resistances at \(0^{\circ} \mathrm{C}\) but their temperature coefficients of resistance are \(\alpha_1\) and \(\alpha_2\). The respective temperature coefficients for their series and parallel combinations are _______. 2024 Hard
- 78. Two resistance of \(100\ \Omega\) and \(200\ \Omega\) are connected in series with a battery of \(4 \mathrm{~V}\) and negligible internal resistance. \(A\) voltmeter is used to measure voltage across \(100 \Omega\) resistance, which gives reading as \(1 \mathrm{~V}\). The resistance of voltmeter must be _______ \(\Omega\). 2024 Hard
- 79. Two wires \(A\) and \(B\) are made up of the same material and have the same mass. Wire A has radius of \(2.0 \mathrm{~mm}\) and wire \(B\) has radius of \(4.0 \mathrm{~mm}\). The resistance of wire B is \(2 \Omega\). The resistance of wire \(\mathrm{A}\) is _______ \(\Omega\). 2024 Hard
- 80. Water boils in an electric kettle in \(20\) minutes after being switched on. Using the same main supply, the length of the heating element should be _______ to _______ times of its initial length if the water is to be boiled in \(15\) minutes. 2024 Hard
- 81. Wheatstone bridge principle is used to measure the specific resistance \(\left(S_1\right)\) of given wire, having length \(L\), radius \(r\). If \(X\) is the resistance of wire, then specific resistance is: \(S_1=X\left(\frac{\pi r^2}{L}\right)\). If the length of the wire gets doubled then the value of specific resistance will be : 2024 Hard
- 82. When a potential difference \(V\) is applied across a wire of resistance \(R\), it dissipates energy at a rate \(W\). If the wire is cut into two halves and these halves are connected mutually parallel across the same supply, the same supply, the energy dissipation rate will become what? 2024 Hard
- 83. \(10\) resistors each of resistance \(10\,\Omega\) can be connected in such as to get maximum and minimum equivalent resistance. The ratio of maximum and minimum equivalent resistance will be \(..........\). 2023 Medium
- 84. A current of \(2\,A\) flows through a wire of crosssectional area \(25.0\,mm ^2\). The number of free electrons in a cubic meter are \(2.0 \times 10^{28}\). The drift velocity of the electrons is \(...............\times 10^{-6}\,ms ^{-1}\) (given, charge on electron \(=1.6 \times 10^{-19}\,C\) ) 2023 Easy
- 85. A hollow cylindrical conductor has length of \(3.14\,m\), while its inner and outer diameters are \(4\,mm\) and \(8\,mm\) respectively. The resistance of the conductor is \(n \times 10^{-3}\,\Omega\).If the resistivity of the material is \(2.4 \times 10^{-8}\,\Omega\,m\). The value of \(n\) is \(..........\) 2023 Medium
- 86. A network of four resistances is connected to \(9\,V\) battery, as shown in figure. The magnitude of voltage difference between the points \(A\) and \(B\) is .......... \(V.\)
2023 Medium - 87. A null point is found at \(200\,cm\) in potentiometer when cell in secondary circuit is shunted by \(5\,\Omega\). When a resistance of \(15\,\Omega\) is used for shunting null point moves to \(300\,cm\). The internal resistance of the cell is \(..............\,\Omega\). 2023 Medium
- 88. A potential \(V_0\) is applied across a uniform wire of resistance \(R\). The power dissipation is \(P_1\). The wire is then cut into two equal halves and a potential of \(V _0\) is applied across the length of each half. The total power dissipation across two wires is \(P_2\). The ratio \(P_2: P_1\) is \(\sqrt{x}: 1\). The value of \(x\) is \(.............\). 2023 Medium
- 89. A rectangular parallelopiped is measured as \(1\,cm \times 1\,cm \times 100\,cm\). If its specific resistance is \(3 \times 10^{-7}\,\Omega\,m\), then the resistance between its two opposite rectangular faces will be \(..........x^{-7} \Omega\). 2023 Easy
- 90. A uniform metallic wire carries a current \(2\,A\). when \(3.4\,V\) battery is connected across it. The mass of uniform metallic wire is \(8.92 \times 10^{-3} \,kg\). density is \(8.92 \times 10^3\,kg / m ^3\) and resistivity is \(1.7 \times 10^{-8} \Omega- m\). The length of wire is \(l=............\,m\) 2023 Medium
- 91. A wire of resistance \(160\,\Omega\) is melted and drawn in wire of one-fourth of its length. The new resistance of the wire will be \(......\Omega\) 2023 Hard
- 92. As shown in the figure, a network of resistors is connected to a battery of \(2\,V\) with an internal resistance of \(3\,\Omega\). The currents through the resistors \(R_4\) and \(R_5\) are \(I_4\) and \(I_5\) respectively. The values of \(I_4\) and \(I_5\) are :
2023 Hard - 93. As shown in the figure, the voltmeter reads \(2\,V\) across \(5\,\Omega\) resistor. The resistance of the voltmeter is \(.......\,\Omega\).
2023 Hard - 94. Different combination of \(3\) resistors of equal resistance \(R\) are shown in the figures.
The increasing order for power dissipation is:
2023 Medium - 95. Equivalent resistance between the adjacent corners of a regular \(n\)-sided polygon of uniform wire of resistance \(R\) would be: 2023 Medium
- 96. Figure shows a part of an electric circuit. The potentials at points \(a , b\) and \(c\) are \(30\,V , 12\,V\) and \(2\,V\) respectively. The current through the \(20 \Omega\) resistor will be \(........\,A\)
2023 Hard - 97. For the given circuit, in the steady state, \(\left| V _{ B }- V _{ D }\right|=.......V.\)
2023 Hard - 98. Given below are two statements Statement \(I:\) The equivalent resistance of resistors in a series combination is smaller than least resistance used in the combination. Statement \(II\) : The resistivity of the material is independent of temperature. In the light of the above statements, choose the correct answer from the options given below 2023 Medium
- 99. If a copper wire is stretched to increase its length by \(20 \% \). The percentage increase in resistance of the wire is \(..........\%\) 2023 Medium
- 100. If the potential difference between \(B\) and \(D\) is zero, the value of \(x\) is \(\frac{1}{n} \Omega\). The value of \(n\) is .......
2023 Medium
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