Class 12th

The tendency of an electrode to lose electron is known as

Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because

Potassium (K) has a bcc structure with nearest neighbor distance 4.52 A⁰ Its atomic weight is 39. Its density will be       

The decreasing order of basic strength of the following is 

 

 

For an endothermic reaction, energy of activation is E_a and enthalpy of reaction is ?H (both of these in kJ/mol). Minimum value of E_a will be

The area of cross-section of cylindrical wire increases uniformly from left to right as shown in figure. When steady current flows in the wire, then in the direction of current

The current in a coil changes from 8 A to zero in 0.2 s. If self-inductance is 4 H then average induced emf is:

In Bohr's model of hydrogen atom, which of the following represents the variation of nth orbit radius with n?

An objective lens of a telescope has diameter 200 cm. The limit of resolution of telescope for wavelength 600 nm is nearly

A radioactive element undergoes successive radioactive decay and decays into The number of a and b– particles emitted respectively are: