For using a multimeter to identify diode from electrical components, choose the correct statement out of the following about the diode :

The velocity of sound in a gas, in which two wavelengths 4.08 m and 4.16 m produce 40 beats in 12s, will be :

A pendulum is suspended by a string of length 250 cm. The mass of the bob of the pendulum is 200 g. The bob is pulled aside until the string is at 60$$^\circ$$ with vertical as shown in the figure. After releasing the bob, the maximum velocity attained by the bob will be ____________ ms^$$-$$1. (if g = 10 m/s²)

A meter bridge setup is shown in the figure. It is used to determine an unknown resistance R using a given resistor of 15 $$\Omega$$. The galvanometer (G) shows null deflection when tapping key is at 43 cm mark from end A. If the end correction for end A is 2 cm, then the determined value of R will be ____________ $$\Omega$$.