Hydrogen atom excites energy level from fundamental state to n = 3. Number of spectrum lines according to Bohr is

In the given circuit, all diodes are ideal. The current through battery is

A block rests on a rough inclined plane making an angle of 30° with the horizontal. Coefficient of static friction between the block and plane is 0.8. If the frictional force on the block is 10 N, find the mass of the block

The internal resistance of a 2.1V cell which gives a current of 0.2A through a resistance of 10 Ω is

In an atom the two electrons move around the nucleus in circular orbits of radii R and 4R. What is the ratio of the times taken by them to complete one revolution?

In the given AC circuit, when switch S is at position 1, the source emf leads current by π / 6. Now, if the switch is at position 2, then

How many unpaired electrons are present in Ni²⁺ cation? (Z = 28)

A colourless water soluble organic liquid decomposes sodium carbonate and liberates CO₂. It produces black ppt . with Tollen’s reagent. The liquid is

On passing 3A of electricity for 50 min, 1.8 g metal is deposited, the equivalent mass of metal is

For the reaction given below, ∆H is equal to

^N2_(g) + ^3H2_(g) ⇄ ^2NH3_(g)

The hydrogen electrode is dipped in a solution of pH = 3 at 25°C. The potential of the cell would be

The principal amplitude of (sin40° + i cos40°)⁵ is

If,

• A = {x : x² - 5x + 6 = 0}
• B = {2, 4}
• C = {4, 5}

then, A x (B ∩ C) is

Find the value of the given integral.

Directions: Choose the word which best expresses the meaning of the underlined word in the sentence.

Decay is an immutable factor of human life.

Directions: Fill in the blank with an appropriate word.

Pradeep’s face spoke ________ for the happiness he was feeling.