NEET Physics | Daily MCQs Practice Questions | 19 July 2024 | NEET Exam

If $\hat{a}$ and $\hat{b}$ are non-collinear unit vectors and $\left| \hat{a} + \hat{b} \right| = \sqrt{3}$, then the value of $(2\hat{a} - 5\hat{b}) \cdot (3\hat{a} + \hat{b})$ is:

When an electron in hydrogen atom is excited from its 4^th to 5^th stationary orbit, the change in angular momentum of electron is :-

Radius of a capillary is 2 × 10^-3 m. Water of weight 6.2 × 10^-4 N may remain in the capillary. Then the surface tension of water will be :-

A man runs towards stationary plane mirror at a speed of 15 m/s. What is speed of his image with respect to mirror ?

A container is filled with water $\left(\mathrm{\mu }=\frac{4}{3}\right)$ upto height 1 m. Find out diameter of disc at top of water surface from which light is coming out.

The magnifying power of an astronomical telescope is 8 and the distance between the two lenses is 54 cm. The focal length of eye lens and objective lens will be respectively

The breakdown in a reverse biased P-N junction diode is more likely to occur due to :-
(a) large velocity of the minority charge carriers if the doping concentration is small.
(b) large velocity of the minority charge carriers if the doping concentration is large.
(c) strong electric field in a depletion region if the doping concentration is small.
(d) Strong electric field in the depletion region if the dopping concentration is large.

A container withinsulating walls isdividedintotwo equal parts by a partition fitted with a valve. One part is filled with an ideal gas at a pressure P and temperature T, whereas the other part is completely evacuated. If the valve is suddenly opened, the pressure and temperature of the gas will be:-

Two close organ pipes having length 20 cm and 20.5 cm produce 5 beats/sec. Determine the frequency of both organ pipes.

In a Young's double slit experiment light has a frequency of 9 × 10¹⁴ Hz. The distance between the centres of adjacent bright fringes is 1 mm. If the screen is 2 m away from the slits, then find the distance between the slits :-

The angle of polarisation for any medium is 60°, what will be critical angle for this ?

A particle is moved from a position $\vec{r_1} = (3\hat{i} + 2\hat{j} - 6\hat{k})$ metre to a position $\vec{r_2} = (14\hat{i} + 13\hat{j} - 9\hat{k})$ metre under the action of a force $\vec{F} = (4\hat{i} + \hat{j} + 3\hat{k})$ N. The work done is equal to:

In the reading shown in the figure, find the zero error

The work function of metal is 1eV. Light of wavelength 3000 Å is incident on this metal surface.
The velocity of emitted photo-electrons will be:-

The magnetic moment of a magnet of mass 75 gm is 9 × 10^-7 A-m² . If the density of the material of magnet is 7.5 × 10³ kg/m³ then intensity of magnetisation will be :-