All STD 12 - Current electricity questions
Newest firstShowing 101–150 of 311 questions
- 101. In a metallic conductor, under the effect of applied electric field, the free electrons of the conductor 2023 Medium
- 102. In a meter bridge experiment the balance point in obtained if the gaps are closed by \(2\,\Omega\) and \(3\,\Omega\). A shunt of \(x\,\Omega\) is added to \(3\,\Omega\) resistor to shift the balancing point by \(22.5\,cm\). The value of \(X\) is \(................\) 2023 Medium
- 103. In an experiment to find \(emf\) of a cell using potentiometer, the length of null point for a cell of emf \(1.5\,V\) is found to be \(60\,cm\). If this cell is replaced by another cell of \(emf\; E\). the length-of null point increases by \(40\,cm\). The value of \(E\) is \(\frac{x}{10} V\). The value of \(x\) is \(............\) 2023 Medium
- 104. In the circuit diagram shown in figure given below, the current flowing through resistance \(3\, \Omega\) is \(\frac{ x }{3}\,A\). The value of \(x\) is \(...........\)
2023 Hard - 105. In the circuit shown, the energy stored in the capacitor is \(n\,\mu J\). The value of \(n\) is ..............
2023 Hard - 106. In the following circuit, the magnitude of current \(I _{ l }\), is \(............A\).
2023 Hard - 107. In the given circuit, the equivalent resistance between the terminal \(A\) and \(B\) is \(........\Omega\).
2023 Medium - 108. In the given circuit the value of \(\left|\frac{I_1+I_3}{I_2}\right|\) is
2023 Medium - 109. In the network shown below, the charge accumulated in the capacitor in steady state will be ........... \(\mu C\)
2023 Medium - 110. In this figure the resistance of the coil of galvanometer \(G\) is \(2\,\Omega\). The emf of the cell is \(4\,V\). The ratio of potential difference across \(C_1\) and \(C_2\) is:
2023 Hard - 111. Ratio of thermal energy released in two resistor \(R\) and \(3 R\) connected in parallel in an electric circuit is : 2023 Easy
- 112. The charge flowing in a conductor changes with time as \(Q ( t )=\alpha t -\beta t ^2+\gamma t ^3\). Where \(\alpha, \beta\) and \(\gamma\) are constants. Minimum value of current is : 2023 Medium
- 113. The current flowing through a conductor connected across a source is \(2\,A\) and \(1.2\,A\) at \(0^{\circ}\,C\) and \(100^{\circ}\,C\) respectively. The current flowing through the conductor at \(50^{\circ}\,C\) will be \(......\times 10^2\,mA\). 2023 Hard
- 114. The current flowing through \(R _2\) is:
2023 Medium - 115. The drift velocity of electrons for a conductor connected in an electrical circuit is \(V _{ d }\). The conductor in now replaced by another conductor with same material and same length but double the area of cross section. The applied voltage remains same. The new drift velocity of electrons will be 2023 Easy
- 116. The equivalent resistance between \(A\) and \(B\) as shown in figure is \(........\,k\Omega\)
2023 Easy - 117. The equivalent resistance between \(A\) and \(B\) is \(......\)
2023 Medium - 118. The equivalent resistance between \(A\) and \(B\) of the network shown in figure
2023 Medium - 119. The equivalent resistance of the circuit shown below between points \(a\) and \(b\) is \(..........\Omega\)
2023 Medium - 120. The length of a metallic wire is increased by \(20 \%\) and its area of cross section is reduced by \(4 \%\). The percentage change in resistance of the metallic wire is \(.......\) 2023 Medium
- 121. The number density of free electrons in copper is nearly \(8 \times 10^{28}\,m ^{-3} . A\) copper wire has its area of cross section \(=2 \times 10^{-6}\,m ^2\) and is carrying a current of \(3.2\,A\). The drift speed of the electrons is \(.....\times 10^{-6}\,ms ^{-1}\). 2023 Easy
- 122. The resistance of a wire is \(5 \Omega\). It's new resistance in ohm if stretched to \(5\) times of it's original length will be : 2023 Medium
- 123. Two cells are connected between points \(A\) and \(B\) as shown. Cell \(1\) has emf of \(12\,V\) and internal resistance of \(3\,\Omega\). Cell \(2\) has emf of \(6\,V\) and internal resistance of \(6\,\Omega\). An external resistor \(R\) of \(4\,\Omega\) is connected across \(A\) and \(B\). The current flowing through \(R\) will be \(.............A\).
2023 Medium - 124. Two identical cells each of emf \(1.5\,V\) are connected in series across a \(10\,\Omega\) resistance. An ideal voltmeter connected across \(10\,\Omega\) resistance reads \(1.5\,V\). The internal resistance of each cell is \(......\Omega\). 2023 Medium
- 125. Two identical cells, when connected either in parallel or in series gives same current in an external resistance \(5\,\Omega\). The internal resistance of each cell will be \(.............\,\Omega\). 2023 Medium
- 126. Two identical heater filaments are connected first in parallel and then in series. At the same applied voltage, the ratio of heat produced in same time for parallel to series will be: 2023 Medium
- 127. When two resistance \(R_1\) and \(R_2\) connected in series and introduced into the left gap of a meter bridge and a resistance of \(10 \Omega\) is introduced into the right gap, a null point is found at \(60 cm\) from left side. When \(R_1\) and \(R_2\) are connected in parallel and introduced into the left gap, a resistance of \(3 \Omega\) is introduced into the right-gap to get null point at 40 cm from left end. The product of \(R_1 R_2\) is \(.............\Omega\) 2023 Hard
- 128. With the help of potentiometer, we can determine the value of emf of a given cell. The sensitivity of the potentiometer is \((A)\) directly proportional to the length of the potentiometer wire \((B)\) directly proportional to the potential gradient of the wire \((C)\) inversely proportional to the potential gradient of the wire \((D)\) inversely proportional to the length of the potentiometer wire Choose the correct option for the above statements: 2023 Medium
- 129. A \(1\,m\) long copper wire carries a current of \(1\,A\). If the cross section of the wire is \(2.0\,mm ^{2}\) and the resistivity of copper is \(1.7 \times 10^{-8}\,\Omega\,m\). the force experienced by moving electron in the wire is \(\times 10^{-23}\,N\). (charge on electron \(=1.6 \times 10^{-19}\,C\) ) 2022 Medium
- 130. A \(1\,m\) long wire is broken into two unequal parts \(X\) and \(Y\) The \(X\) part of the wire is streched into another wire \(W\). Length of \(W\) is twice the length of \(X\) and the resistance of \(W\) is twice that of \(Y\). Find the ratio of length of \(X\) and \(Y\). 2022 Medium
- 131. A \(220 \; V , 50 \; Hz\) AC source is connected to a \(25 \; V\), \(5 \; W\) lamp and an additional resistance \(R\) in series (as shown in figure) to run the lamp at its peak brightness, then the value of \(R\) (in ohm) will be
2022 Medium - 132. A battery of \(6\,V\) is connected to the circuit as shown below. The current I drawn from the battery is:
2022 Medium - 133. A cell, shunted by a \(8 \; \Omega\) resistance, is balanced across a potentiometer wire of length \(3 \; m\). The balancing length is \(2 \; m\) when the cell is shunted by \(4 \; \Omega\) resistance. The value of internal resistance of the cell will be \(\dots \; \Omega .\) 2022 Medium
- 134. A current of \(15\,mA\) flows in the circuit as shown in figure. The value of potential difference between the points \(A\) and \(B\) will be \(...\,V\)
2022 Medium - 135. A meter bridge setup is shown in the figure. It is used to determine an unknown resistance \(R\) using a given resistor of \(15\,\Omega\). The galvanometer \((G)\) shows null deflection when tapping key is at \(43\,cm\) mark from end \(A\). If the end correction for end \(A\) is \(2\,cm\). then the determined value of \(R\) will be__________ \(\Omega\)
2022 Hard - 136. A potentiometer wire of length \(10 \,m\) and resistance\(20 \,\Omega\) is connected in series with a \(25 \,V\) battery and an external resistance \(30\, \Omega\). A cell of emf \(E\) in secondary circuit is balanced by \(250\, cm\) long potentiometer wire. The value of \(E\) (in volt) is \(\frac{x}{10}\). The value of \(x\) is....... 2022 Medium
- 137. A potentiometer wire of length \(300\,cm\) is connected in series with a resistance \(780\,\Omega\) and a standard cell of emf \(4\,V\). A constant current flows through potentiometer wire. The length of the null point for cell of emf \(20\,mV\) is found to be \(60\,cm\). The resistance of the potentiometer wire is\(...\Omega\)
2022 Hard - 138. A resistor develops \(300 \,J\) of thermal energy in \(15 \,s\), when a current of \(2\, A\) is passed through it. If the current increases to \(3 \,A\), the energy developed in \(10\,\,s\) is........\(J.\) 2022 Medium
- 139. \(A\). The drift velocity of electrons decreases with the increase in the temperature of conductor. \(B\). The drift velocity is inversely proportional to the area of cross-section of given conductor. \(C\). The drift velocity does not depend on the applied potential difference to the conductor. \(D\). The drift velocity of electron is inversely proportional to the length of the conductor. \(E\). The drift velocity increases with the increase in the temperature of conductor. Choose the correct answer from the options given below: 2022 Hard
- 140. A wire of resistance \(R_{1}\) is drawn out so that its length is increased by twice of its original length.The ratio of new resistance to original resistance is. 2022 Easy
- 141. All resistances in figure are \(1\,\Omega\) each. The value of current ' \(I\) ' is \(\frac{a}{5}\,A\). The value of \(a\) is
2022 Hard - 142. An aluminium wire is stretched to make its length, \(0.4 \,\%\) larger. Then percentage change in resistance is \(.....\,\%\) 2022 Medium
- 143. An electrical bulb rated \(220\,V , 100\,W\), is connected in series with another bulb rated \(220\,V\), \(60\,W\).If the voltage across combination is \(220\,V\), the power consumed by the \(100\,W\) bulb will be about \(........... W\) 2022 Medium
- 144. As show in the figure, in steady state, the charge stored in the capacitor is....... \(\times 10^{-6}\,C\).
2022 Hard - 145. As shown in the figure, a potentiometer wire of resistance \(20\,\Omega\) and length \(300\,cm\) is connected with resistance box (R.B.) and a standard cell of emf \(4\,V\). For a resistance ' \(R\) ' of resistance box introduced into the circuit, the null point for a cell of \(20\,mV\) is found to be \(60\,cm\). The value of ' \(R\) ' is \(.....\Omega\)
2022 Medium - 146. Current measured by the ammeter \((A)\) in the reported circuit when no current flows through \(10\,\Omega\) resistance. will be________\(A\)
2022 Hard - 147. Eight copper wire of length \(l\) and diameter \(d\) are joined in parallel to form a single composite conductor of resistance \(R\). If a single copper wire of length \(2\,l\) have the same resistance \((R)\) then its diameter will be \(.....d\). 2022 Easy
- 148. For the given circuit the current through battery of \(6\,V\) just after closing the switch ' \(S\) ' will be\(.......A\).
2022 Medium - 149. For the network shown below, the value \(V _{ B }- V _{ A }\) is_______ \(V\)
2022 Medium - 150. Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason \(R\). Assertion \(A:\) Alloys such as constantan and manganin are used in making standard resistance coils. Reason \(R:\) Constantan and manganin have very small value of temperature coefficient of resistance.In the light of the above statements, choose the correct answer from the options given below. 2022 Medium
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