Class 12th

Arrange the four graphs in descending order of total work done; where W₁, W₂, W₃ and W₄ are the work done corresponding to figure a, b, c and d respectively.

(a) W₃ > W₂ > W₁ >W₄        (b) W₃ > W₂ > W₄ > W₁   (c)         (d) W₂ > W₃ > W₁ > W₄

In the arrangement shown in figure a₁, a₂, a₃ and a₄ are the accelerations of masses m₁, m₂, m₃ and m₄ respectively. Which of the following relation is true for this arrangement?

Production of iron in blast furnace follows the following equation

$F{e}_3{O}_4\left(s\right)+4CO\left(g\right)\to 3Fe\left(I\right)+4C{O}_2\left(g\right)$

When 4.640 kg of Fe₃O₄ and 2.520 kg of CO are allowed to react then the amount of iron (in g) produced is:

[Given : Molar Atomic mass (g mo^-1); Fe = 56

Molar Atomic mass (g mol^-1); O = 16

Molar Atomic mass (g mol^-1); C = 12]

Time period of a simple pendulum in a stationary lift is 'T'. If the lift accelerated with $\frac{g}{6}$ vertically upwards then the time period will be:

(Where g = acceleration due to gravity)

The dimension of mutual inductance is:

The efficiency of a Carnot's engine, working between stem point and ice point, will be

Let b₁ b₂ b₃ b₄ be a 4-element permutation with $b_i\in \left\{1,2,3,....,100\right\}for1\le i\le 4and{b}_i\ne b_j$ for $i\ne j,$ such that either b_1, b₂, b₃ are consecutive integers or b₂, b₃, b₄ are consecutive integers. Then the number of such permutations b₁ b₂ b₃ b₄ is equal to……………

The variation of acceleration due to gravity (g) with distance (r) from the centre of the earth is correctly represented by: (Given R = radius of earth)

The variation of acceleration due to gravity (g) with distance (r) from the centre of the earth is correctly represented by: (Given R = radius of earth)