DEMOEXAM | ScoreExams

Question 1 of 10

Which of the following on thermal decomposition yields a basic as well as an acidic oxide?

A{tex}KClO_3{/tex}

B{tex}Na_2CO_3{/tex}

C{tex}NaNO_3{/tex}

D{tex}CaCO_3{/tex}

Question 2 of 10

Both ethene and ethyne can be made in one step reactions from

A{tex}Br - CH_2 - CH_2Br{/tex}

B{tex}CH_3 - CH_2OH{/tex}

C{tex}CH_3 - CH_2Br{/tex}

D{tex}CHCl_3{/tex}

Question 3 of 10

Fear or exitement, generally cause one to breath rapidly and it results in the decrease of {tex}CO_2{/tex} concentration in blood. In what way will it change the pH of blood?

ApH will increase

BpH will decrease

CNo change

DpH will adjust to 7

Question 4 of 10

If vector a = i + 2j + 3k and b = i × (a×i) + j×(a×j) + k×(a×k) then length of b is equal to

A√12

B2 √12

C3 √14

D2 √14

Question 5 of 10

Which compound among the following give/s positive iodoform test?
1. Ethanol
2. Ethanal
3. 1-butanol
4. 2-butanol
5. Phenyl ethanal

A1, 2 and 5

B1, 3 and 4

C1, 2 and 3

D1, 2 and 4

Question 6 of 10

Two identical balls A and B collide head on elastically. If the velocity of A and B before collision are 0.5 m/s and -0.3m/s respectively, then their velocities after collision will be

A0.5 m/s and 0.3 m/s

B-0.5ms^-1 and 0.3ms^-1

C0.3ms^-1 and -0.5ms^-1

D-0.3ms^-1 and 0.5ms^-1

Question 7 of 10

The two slits are 1 mm apart from each other and illuminated with a light of wavelength 5 x 10^-7 m. If the distance of the screen is 1 m from the slits, then the distance between third dark fringe and fifth bright fringe is

A1.5 mm

B0.75 mm

C1.25 mm

D0.625 mm

E2.5 mm

Question 8 of 10

In Young's double slit experiment, the width of one of the slits is slowly increased to make it twice the width of the other slit. Then in the interference pattern:

Athe intensity of maxima increase while that of minima decrease

Bintensities of both maxima and minima decrease

Cthe intensities of both maxima and minima remain the same

Dthe intensities of both maxima and minima increase

Question 9 of 10

Sulphur trioxide can be obtained by which of the following reaction.

A{tex}CaSO_4 + C x\rightarrow{\Delta}{/tex}

B{tex}Fe_2 (SO_4)_3 + C x\rightarrow{\Delta}{/tex}

C{tex}S + H_2 SO_4 x\rightarrow{\Delta}{/tex}

D{tex}H_2 SO_4 + PCl_5 x\rightarrow{\Delta}{/tex}

Question 10 of 10

A sample of radioactive substance with half-life of 3 days was found to contain only 3g of it, when received exactly 12 days after sealing.The amount of the radeioactive substance when it was sealed, was :

A6g

B12 g

C24 g

D48 g