Class 11th

lim(x→0) (tan(π/4 + x))¹/? is equal to

If the sum of first 11 terms of an A.P. a?, a?, a?, . is 0 (a? ≠ 0), then the sum of the A.P. a?, a?, a?, ., a? is ka?, where k is equal to

Let f(x) be a quadratic polynomial such that f(-1) + f(2) = 0. If one of the roots of f(x)=0 is 3, then its other root lies in

If the equation cos?θ + sin?θ + λ = 0 has real solutions for θ, then λ lies in the interval

If you spill a chemical toilet cleaning liquid on your hand, your first aid would be:

Three elements X, Y and Z are in the 3rd period of the periodic table. The oxides of X, Y and Z, respectively, are basic, amphoteric and acidic. The correct order of the atomic numbers of X, Y and Z is:

Two elements A and B have similar chemical properties. They don't form solid hydrogencarbonates, but react with nitrogen to form nitrides. A and B, respectively, are:

Match the type of interaction in column A with the distance dependence of their interaction energy in column B:

The internal energy change (in J) when 90 g of water undergoes complete evaporation at 100°C is 
(Given: ΔH_vap for water at 373K = 41 kJ/mol, R = 8.314 JK?¹mol?¹)

The number of subshells associated with n=4 and m=-2 quantum numbers is: