1
JEE Main 2024 (Online) 31st January Morning Shift
+4
-1

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 :

A
$$\alpha_1+\alpha_2, \frac{\alpha_1 \alpha_2}{\alpha_1+\alpha_2}$$
B
$$\frac{\alpha_1+\alpha_2}{2}, \frac{\alpha_1+\alpha_2}{2}$$
C
$$\alpha_1+\alpha_2, \frac{\alpha_1+\alpha_2}{2}$$
D
$$\frac{\alpha_1+\alpha_2}{2}, \alpha_1+\alpha_2$$
2
JEE Main 2024 (Online) 30th January Evening Shift
+4
-1

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 energy dissipation rate will become:

A
1/2W
B
4W
C
1/4W
D
2W
3
JEE Main 2024 (Online) 30th January Morning Shift
+4
-1

A potential divider circuit is shown in figure. The output voltage V$$_0$$ is :

A
2 mV
B
4 V
C
0.5 V
D
12 mV
4
JEE Main 2024 (Online) 30th January Morning Shift
+4
-1

An electric toaster has resistance of $$60 \Omega$$ at room temperature $$\left(27^{\circ} \mathrm{C}\right)$$. The toaster is connected to a $$220 \mathrm{~V}$$ supply. If the current flowing through it reaches $$2.75 \mathrm{~A}$$, the temperature attained by toaster is around : ( if $$\alpha=2 \times 10^{-4}$$/$$^\circ \mathrm{C}$$)

A
1235 $$^\circ$$C
B
1667 $$^\circ$$C
C
694 $$^\circ$$C
D
1694 $$^\circ$$C
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