List of practice Questions

When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted electron is v₁. When the frequency of incident radiation is increased to five times the threshold value, the maximum velocity of emitted electron becomes v₂. If v₂ = x v₁, the value of x will be ________.

From the top of a tower, a ball is thrown vertically upward which reaches the ground in 6 s. A second ball thrown vertically downward from the same position with the same speed reaches the ground in 1.5 s. A third ball released, from the rest from the same location, will reach the ground in ____ s.

If y = y(x) is the solution of the differential equation

\(2x^2\frac{dy}{dx}-2xy+3y^2=0\) such that \(y(e)=\frac{e}{3},\)

then y(1) is equal to

If the angle made by the tangent at the point (x₀, y₀) on the curve x = 12(t + sin t cos t), 

\(y=12(1+sint)^2,0<t<\frac{π}{2}, \)

with the positive x-axis is π/3, then y₀ is equal to

In a potentiometer arrangement, a cell gives a balancing point at 75 cm length of wire. This cell is now replaced by another cell of unknown emf. If the ratio of the emf’s of two cells respectively is 3 : 2, the difference in the balancing length of the potentiometer wire in above two cases will be _____ cm.

Which of the following sets of quantum numbers is not allowed?

The depression in the freezing point observed for a formic acid solution of concentration 0.5 mL L^–1 is 0.0405°C. Density of formic acid is 1.05 g mL^–1. The Van’t Hoff factor of the formic acid solution is nearly (Given for water k_f = 1.86 k kg mol^–1)

The IUPAC nomenclature of an element with electronic configuration [Rn] 5f¹⁴6d¹7s² is

Choose the correct order of density of the alkali metals.