In the circuit shown cells, \(A\) and \(B\) have negligible resistance. For \(V_A =12 ~\text{V}\), \(R_1 = 500 ~\Omega \), and \(R = 100 ~\Omega \) the galvanometer \((\text{G}) \) shows no deflection. The value of \(V_B\) is:
1. \(4\) V
2. \(2\) V
3. \(12\) V
4. \(6\) V
If the voltage across a bulb rated \((220~\text{V}\text-100~\text{W})\) drops by \(2.5\%\) of its rated value, the percentage of the rated value by which the power would decrease is:
1. \(20\%\)
2. \(2.5\%\)
3. \(5\%\)
4. \(10\%\)
A ring is made of a wire having a resistance of \(R_0=12~\Omega.\). Find points \(\mathrm{A}\) and \(\mathrm{B}\), as shown in the figure, at which a current-carrying conductor should be connected so that the resistance \(R\) of the subcircuit between these points equals \(\frac{8}{3}~\Omega\)
1. \(\frac{l_1}{l_2} = \frac{5}{8}\)
2. \(\frac{l_1}{l_2} = \frac{1}{3}\)
3. \(\frac{l_1}{l_2} = \frac{3}{8}\)
4. \(\frac{l_1}{l_2} = \frac{1}{2}\)
If power dissipated in the 9 resistor in the circuit shown is 36 W, the potential difference across the 2 resistor will be:
1. 8 V
2. 10 V
3. 2 V
4. 4 V
A current of 2 A flows through a 2 resistor when connected across a battery. The same battery supplies a current of 0.5 A when connected across a 9 resistor. The internal resistance of the battery is:
1. 1/3
2. 1/4
3. 1
4. 0.5
1. | is zero. |
2. | depends upon the choice of the two materials of the thermocouple. |
3. | is negative. |
4. | is positive. |
A potentiometer circuit is set up as shown in the figure below. The potential gradient across the potentiometer wire is k volt/cm. Ammeter present in the circuit reads 1.0 A when the two-way key is switched off. The balance points, when the key between the terminals (i) 1 and 2 (ii) 1 and 3, is plugged in, are found to be at lengths and respectively. The magnitudes of the resistors R and X in ohm, are then, respectively, equal to:
1.
2.
3.
4.
Given below two statements:
Statement I: | Kirchhoff’s junction law follows the conservation of charge. |
Statement II: | Kirchhoff’s loop law follows the conservation of energy. |
1. | Both Statement I and Statement II are wrong. |
2. | Statement I is correct but Statement II is wrong. |
3. | Statement I is wrong and Statement II is correct. |
4. | Both Statement I and Statement II are correct. |