For the circuit shown below, the propagation delay of each NAND gate is 1 ns. The critical path delay, in ns, is __________ (rounded off to the nearest integer).

In a given sequential circuit, initial states are Q$$_1$$ = 1 and Q$$_2$$ = 0. For a clock frequency of 1 MHz, the frequency of signal Q$$_2$$ in kHz, is ___________ (rounded off to the nearest integer).

Consider a narrow band signal, propagating in a lossless dielectric medium $$(\varepsilon_r=4,\mu_r=1)$$, with phase velocity $$v_p$$ and group velocity $$v_g$$. Which of the following statement is true? ($$c$$ is the velocity of light in vacuum.)

The standing wave ratio on a 50 $$\Omega$$ lossless transmission line terminated in an unknown load impedance is found to be 2.0. The distance between successive voltage minima is 30 cm and the first minimum is located at 10 cm from the load. $$Z_L$$ can be replaced by an equivalent length $$l_m$$ and terminating resistance $$R_m$$ of the same line. The value of $$R_m$$ and $$l_m$$, respectively, are