A convex lens has power \( P \). It is cut into two halves along its principal axis. Further, one piece (out of two halves) is cut into two halves perpendicular to the principal axis as shown in the figure. Choose the incorrect option for the reported lens pieces.
The equation \[ 2 \cos^{-1} x = \sin^{-1} \left( 2 \sqrt{1 - x^2} \right) \] is valid for all values of \(x\) satisfying:
A metallic sphere of radius \( R \) carrying a charge \( q \) is kept at a certain distance from another metallic sphere of radius \( R_4 \) carrying a charge \( Q \). What is the electric flux at any point inside the metallic sphere of radius \( R \) due to the sphere of radius \( R_4 \)?
The circuit shown in the figure contains two ideal diodes \( D_1 \) and \( D_2 \). If a cell of emf 3V and negligible internal resistance is connected as shown, then the current through \( 70 \, \Omega \) resistance (in amperes) is:
Phenol is a different class of organic compounds that are usually found in wide usage in an extensive range of industries and also for domestic purposes. Phenol is formed when a hydrogen atom in a benzene molecule is replaced by the chemical -OH group.
Phenol is also called as Carbolic acid. It is an aromatic organic compound having the molecular formula C6H5OH. It is a volatile white crystalline solid. The molecule consists of a phenyl group (−C6H5) bonded to a hydroxy group (−OH). Phenol is mildly acidic, it requires careful handling because it can cause chemical burns.
On the basis of the different number of hydroxyl groups attached, the phenols can be classified further into three types.