JEE question bank, practice MCQ , Notes, Lectures

1 General Principles & Process of Isolation of Metals

What produce when a mixture of Cu₂O and Cu₂S is heated?

1) O₂
2) SO₂
3) H₂S
4) None of these

Option 1

Option 2 Solution:

SOLUTION

It undergoes auto reduction forming copper and sulphur dioxide.
$$2{ Cu }_{ 2 }O+{ Cu }_{ 2 }S\xrightarrow { heat } 6Cu+S{ O }_{ 2 }$$

Option 3

Option 4

2 D and F Block Elements

Most probable oxidation state of Pb and Sn will be

1) Pb⁴⁺ Sn⁴⁺
2) Pb⁴⁺ Sn²⁺
3) Pb²⁺,Sn²⁺
4) Pb²⁺,Sn⁴⁺

Option 1

Option 2

Option 3

Option 4 Solution:

SOLUTION

3 Sequences and Series

Let S _k be the sum of an infinite GP series whose first term k is k and common ratio is k/(k + 1) (k> 0). Then, the value of

1) log_e 4
2) log_e 2 – 1
3) 1 - log_e 2
4) 1 - log_e 4

Option 1 Solution:

SOLUTION

Option 2

Option 3

Option 4

4 Dual Nature Of Radiation And Matter

If $$K_{1}$$ and $$K_{2}$$ are maximum kinetic energies of photoelectrons emitted when lights of wavelength $$\lambda_{1}$$ and $$\lambda_{2}$$ respectively incident on a metallic surface if $$\lambda_{1}=3\lambda_{2}$$, then

1) $$K_{1} > \, (K_{2}/3)$$
2) $$K_{1}<\, (K_{2}/3)$$
3) $$K_{1}=3K_{2}$$
4) $$K_{2}=3K_{1}$$

Option 1

Option 2 Solution:

Solution:

According to Einsteins photoelectric equation

$$\frac{hc}{\lambda}=\phi_{0}+KE_{max}$$

$$\therefore K_{1}=\frac{hc}{\lambda_{1}}-\phi_{0}$$ and $$K_{2}=\frac{hc}{\lambda_{2}}-\phi_{0}$$

or $$K_{1}-K_{2}=hc \left[\frac{1}{\lambda_{1}}-\frac{1}{\lambda_{2}}\right]$$

$$=hc\left[\frac{1}{3\lambda_{2}}-\frac{1}{\lambda_{2}}\right]=-\frac{2hc}{3\,\lambda_{2}}$$ (Given $$\lambda_{1}=3\lambda_{2}$$)

$$K_{1}-K_{2}=-\frac{2}{3}\left(K_{2}+\phi_{0}\right)$$

or $$K_{1}=K_{2}-\frac{2}{3} \phi_{0} =\frac{K_{2}}{3}-\frac{2}{3} \phi_{0}$$ or $$K_{1}<\, \frac{K_{2}}{3}$$

Option 3

Option 4

5 Sets relations and functions

If is equal to

1) (f(x))²
2) 2f(x)
3) - 2f(x)
4) 2f(x²)

Option 1

Option 2 Solution:

SOLUTION

= 2f(x)

Option 3

Option 4

6 Differential Equations

The differential equation for the family of curves x² + y²-2ay =0, where a is an arbitrary constant is

1) 2(x²-y²)y'=xy
2) 2(x²+y²)y'=xy
3) (x²-y²)y'= 2xy
4) (x²+y²)y'=2xy

Option 1

Option 2

Option 3 Solution:

SOLUTION

2x + 2yy′ - 2ay′ = 0

(eliminating a)

⇒ (x² – y² )y′ = 2xy.

Option 4

7 Kinematics

The resultant of three vectors

1) r
2) 2r
3) r(1 + Ö 2)
4) r(Ö 2 - 1)

Option 1

Option 2

Option 3 Solution:

SOLUTION

Option 4

8 Atomic Structure

Which of the following set of quantum numbers is possible?

Option 1

Option 2

Option 3 Solution:

SOLUTION

Only option 3 is possible. In the alternative 1, l = 0. Hence m value must be 0. Spin quantum number can never be zero. So option 2 is wrong. Even the option 4 is wrong since when

n = 1, l value should be zero.

Option 4

9 Sets relations and functions

Let f (x) = and g (x) be the inverse of f(x), then which one of the following holds good?

1) 2g'' = g2
2) 2g'' = 3g²
3) 3g'' = 2g²
4) 3g'' = g²

Option 1

Option 2 Solution:

Solution

Option 3

Option 4

10 Ionic Equilibrium

What volume of decinormal K₂Cr₂O₇ solution would be needed to convert 1.19 g of tin to stannic chloride in an acidic medium? (ASn = 119ASn = 119)

1) 400 ml
2) 200 ml
3) 100 ml
4) 2800 ml

Option 1 Solution:

SOLUTION

No.of moles of tin in 1.19g of tin=1.19=1.19

n=0.01

as Sn is converting to SnCl₄ i.e. Sn⁰→Sn⁺⁴

Thus n_f= 4

Normality of Kr₂Cr₂O₇ = O.1N

∴0.1N×V=0.01×4

V=0.42=400ml

400ml of volume of decinormal Kr₂Cr₂O₇solution would be needed

Option 2

Option 3

Option 4

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