Tracheids differ from other tracheary elements in

Which of the following is incorrectly matched?

The heat energy absorbed by a system undergoing the cyclic process shown in the figure is:

The first line in the Lyman series has wavelength $\lambda$. The wavelength of the first line in the Balmer series is

When a point source of monochromatic light is placed at a distance of $0.2 \ m$ from a photoelectric cell,the cut-off voltage and saturation current are $0.6 \ V$ and $18 \ mA$ respectively. If the same source is placed at a distance of $0.6 \ m$ from the photoelectric cell,then:

When $100 \, V$ $DC$ is applied across a solenoid,a current of $1 \, A$ flows in it. When $100 \, V$ $AC$ is applied across the same coil,the current drops to $0.5 \, A$. If the frequency of the $AC$ source is $50 \, Hz$,the impedance and inductance of the solenoid are: