Blog Log in Get Started Free

Physics MCQs for NEET — Practice Questions with Answers

Practice free Physics NEET multiple-choice questions online with instant answers and detailed explanations. No login required.

All Physics Chemistry Botany Zoology

Chapter Language Difficulty Show only questions I answered incorrectly Register free to filter questions

● ● ● ● ●

The half life time of a radioactive elements of x is the same as the mean life of another radioactive element Y. Initially they have same number of atoms, then

A. y will decay faster then x B. x will decay faster then y C. x and y will decay at the same rate at all time D. x and y will decay at the same rate initially.

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$ ( T 1/2)_x = {0.693 \over \lambda x} (T)_Y = {1\over \lambda y} ({T_1 \over 2 })_x= T_y $ ${0.693 \over \lambda x} = {1/ \lambda y}$ $\therefore \lambda y = {dx \over 0.693 }$ $({T_1 \over 2 })_X= (T)_y $ $ \lambda y = 1.44 \lambda x $ $ {0.693 \over \lambda x} = { 1 \over \lambda y}$ $ According N = No\,e^{-\lambda t }$

● ● ● ● ●

which of the following transition in hydrogen atoms emits Photon of highest frequency?

A. n=2 to n=6 B. n=1 to n=2 C. n=2 to n=1 D. n=6 to n=2

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

n = 2 to n = 6 absorbs photon n = 9 to n = 2 absorbs photon n = 6 to n = 2 emission of photon n = 2 to n = 1 emission of photon $E = E_2-E_1 = {-13.6 \over 36}-({-13.6 \over 4 }) = -0.38+13.6 = 3.02 eV $ $ \triangle \Sigma^1 = E_2-E_1 = {-13.6 \over 4}-({-13.6 \over 1}) = -3.4+13.6 = 10.2 eV $ $ \triangle \Sigma^1 > \triangle E$ $hf' > hf $

● ● ● ● ●

An electron Passing through a Potential difference of 4.9 v collides with a mercury atom and transfer it to the first excited state what is transfer it to the first excited state. what is the wave length of Photon corresponding to the franition of mercury atom to its normal state.

$ 2050 A ^ \circ $

$ 2935 A ^ \circ $

$ 2525 A ^ \circ $

$ 2240 A ^\circ $

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

energy of electron = ve $ E = 4.9 \times 1.6 \times 10 ^ {-19} J $ ${ hc \over \lambda} \Rightarrow \lambda = {hc \over E} $

● ● ● ● ●

The speed of daughter nuclei is

A. $ (\triangle m)c \over M+\triangle m$ B. $ C \sqrt{\triangle m\over m}$ C. $ C \sqrt{2(\triangle m)\over M}$ D. $ C \sqrt{\triangle m\over M+ \triangle m}$

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$ {1 \over 2} Mv^2 = ( \triangle m)C^2$ $ V^2 = {2(\triangle m) C^2 \over M}$ $V = C {\sqrt{2(\triangle m)} \over m}$

● ● ● ● ●

Light form the discharge tube containing hydrogen atom falls on the surface of a Piece of sodium. The kinetic energy of the fastest photo electrons emitted form sodium is 0.73 eV. The work function for sodium is 1.82 eV. Ionigation Potential of hydrogen is 13.6 v and the mass of hydrogen atom is $1.67 \times 10^{-27}$ kg. (i) The energy of Photon causing the Photo electric emission is

A. $ 4.08\times 10^{-19}$ B. $ 2.912 \times 10^{-19}$ C. $1.744 \times 10^{-19}$ D. $ 1.168 \times 10^{-19}$

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$ K_{max} = hf - \phi $ $ hf = K_{max} + \phi $

● ● ● ● ●

Light form the discharge tube containing hydrogen atom falls on the surface of a Piece of sodium. The kinetic energy of the fastest photo electrons emitted form sodium is 0.73 eV. The work function for sodium is 1.82 eV. Ionigation Potential of hydrogen is 13.6 v and the mass of hydrogen atom is $1.67 \times 10^{-27}$ kg. (ii) The quantum number of the two leVels in the emission of the Photons are

A. n=1 , n=3 B. n=2 , n=4 C. n=1 , n=4 D. n=3 , n=4

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

Correspnding energy level for 2.55 eV is n = 2 , n = 4

● ● ● ● ●

Light form the discharge tube containing hydrogen atom falls on the surface of a Piece of sodium. The kinetic energy of the fastest photo electrons emitted form sodium is 0.73 eV. The work function for sodium is 1.82 eV. Ionigation Potential of hydrogen is 13.6 v and the mass of hydrogen atom is $1.67 \times 10^{-27}$ kg. (iii) In this transition change in the angular momentum of electron is ( where h is Plank Constant )

A. $ h \over 2 \pi $ B. $ h \over \pi $ C. $ 2 h \over \pi $ D. $ 3h \over 2 \pi $

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$Change \,Angular \, momentum = {4h \over 2 \pi } - {2h \over 2 \pi} \Rightarrow {2h \over \pi} - { h \over \pi } \Rightarrow {h \over \pi }$

● ● ● ● ●

Light form the discharge tube containing hydrogen atom falls on the surface of a Piece of sodium. The kinetic energy of the fastest photo electrons emitted form sodium is 0.73 eV. The work function for sodium is 1.82 eV. Ionigation Potential of hydrogen is 13.6 v and the mass of hydrogen atom is $1.67 \times 10^{-27}$ kg. (iv) The recoil speed of emitting atom causing that is atleast before the transition is of order of

A. $ 1\, {cms} ^ -1$ B. $ {10}^2\, {ms} ^ -1$ C. $ {10}^4\, {ms} ^ -1$ D. $ 1\, {ms} ^ -1$

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

According to conservation of momentum momentum of photon = momentum of lecoil altom ${ h \over \lambda } = mu $ $ \upsilon = { h \over m \lambda } = { hf \over mc } = E/mc $

● ● ● ● ●

A and B are two radioactive substance whose half lives are 1 and 2 years respectively. Initially 10 g of A and 1 g of B is taken. The time after which they will have same quantity remaining is

A. 3.6 years B. 7 years C. 6.6 years D. 5 years

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$ {m_1 \over mb_1} = ( {1\over 2}) ^{1\over T1/2} = ({1 \over 2}) ^{t \over 1} = { 1 \over 2^t}$ $ m_1 = {10 \over 2^+} $ $ m_1 = m_2 $ $ m_2 = {1 \over 2^{t /2}}$ ${10 \over 2^t } = {1 \over 2^{t/2}}$ $ 10 = (2)^{t/2}$ $ log 10 = t/2 log 2 $ $1.0000 = {t \over 2} \times 0.3010 $ $ t =6.64 year \approx 6.6 year $

● ● ● ● ●

which of these is a fusion reaction

A. $ _1^3H + _1^2 H = _2^4 {He} + n_0^1 $ B. $ _7^{12}H \rightarrow C_6^{12} = \beta^+ + g $ C. $ _{92} U ^{218} \rightarrow _{81} ^{206} Pb + 8( _2 ^4 He ) + 6 ( _ - e ^ o) $ D. None of these

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$_1^3H +_1^2H = _2^4 He + \,_0n^1$

Ready to ace NEET?

Free access · No credit card required

Browse All Questions Create Free Account

Frequently Asked Questions

Yes. You can attempt every Physics question on this page for free without logging in, and check the correct answer with a detailed explanation instantly.

No account is required to attempt questions and view answers. A free account adds bookmarks, personal notes, and progress tracking.

The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.