An organic compound $X$ on treatment with pyridinium chlorochromate in dichloromethane gives compound $Y$. Compound $Y$ reacts with $I_2$ and alkali to form triiodomethane. The compound $X$ is

$A$ driver applies the brakes on seeing the red traffic signal $400 ~m$ ahead. At the time of applying the brakes,the vehicle was moving with $15 ~m/s$ and retarding at $0.3 ~m/s^2$. The distance covered by the vehicle from the traffic light $1$ minute after the application of brakes is (in $~m$)

The magnitude of maximum acceleration is $\pi$ times that of maximum velocity of a simple harmonic oscillator. The time period of the oscillator in seconds is

$A$ motor of power $P_0$ is used to deliver water at a certain rate through a given horizontal pipe. To increase the rate of flow of water through the same pipe $n$ times,the power of the motor is increased to $P_1$. The ratio of $P_1$ to $P_0$ is

The compound in which the number of $d\pi - p\pi$ bonds are equal to those present in $ClO_4^{-}$ is:

In an industrial process,$10\, kg$ of water per hour is to be heated from $20^\circ C$ to $80^\circ C$. To do this,steam at $200^\circ C$ is passed from a boiler into a copper coil immersed in water. The steam condenses in the coil and is returned to the boiler as water at $90^\circ C$. How many $kg$ of steam is required per hour? (Specific heat of steam $= 0.5\, cal/g^\circ C$,Latent heat of vaporisation $= 540\, cal/g$,Specific heat of water $= 1\, cal/g^\circ C$)