One end of a stecl wire is fixed to the ceiling of an elevator moving up with an acceleration $2 \mathrm{~m} / \mathrm{s}^2$ and a load of 10 kg hangs from the other end. If the cross section of the wire is $2 \mathrm{~cm}^2$, then the longitudinal strain in the wire will be ( $\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2$ and $\mathrm{Y}=2.0 \times 10^{11} \mathrm{~N} / \mathrm{m}^2$ )
Ruma reached the metro station and found that the escalator was not working. She walked up the stationary escalator with velocity $v_1$ in time $t_1$. On other day if she remains stationary on the escalator moving with velocity $v_2$, then escalator takes her up in time $t_2$. The time taken by her to walk up with velocity $v_1$ on the moving escalator will be
A quantity $X$ is given by $\varepsilon_0 L \frac{\Delta V}{\Delta t}$, where $\varepsilon_0$ is the permittivity of free space, $L$ is the length, $\Delta V$ is a potential difference and $\Delta t$ is a time interval. The dimension of $X$ is same as that of
A diode is connected in parallel with a resistance as shown in Figure. The most probable current (I) - voltage (V) characteristic is



