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1. 4

Light of wavelength $2475\dot{A}$ is incident on barium. Photoelectrons emitted describe a circle of maximum radius of $100\text{cm}$ in a magnetic field of flux density $\frac{1}{\sqrt{17}}\times {10}^{-5}$$\text{T}$. Find the work function of Barium.



$(\frac{e}{m}=1.7\times {10}^{11}:\text{Take}hc=12375\text{eV}\dot{\text{A}})$

An old man goes for morning walk on a semi-circular track of radius $28\text{m}$, if he starts from one end of the track and reaches to other end, the distance covered by the man will be

(Take $\pi =\frac{22}{7}$)

Radius of gyration of a body about an axis$\left(I_A\right)$ is $5\text{m}$. Perpendicular distance of $\left(I_A\right)$ from center of mass of body is $3\text{m}$. Find its radius of gyration about an axis$\left(I_B\right)$ which is parallel to $\left(I_A\right)$ and also passing through center of mass of body.

In $C{H}_4$ molecule, there are four $C-H$ bonds. If two adjacent bonds are in $\hat{i}+\hat{j}+\hat{k}$ and $\hat{i}-\hat{j}-\hat{k}$ direction, then find the angle between these bonds.

More than One Answer Type

एक से अधिक उत्तर प्रकार के प्रश्न



A uniform disc of mass M and radius R is given velocity v₀ and angular velocity ${\omega }_0=\frac{2v_0}{R}$ at t = 0 on rough horizontal surface as shown. It starts pure rolling with velocity v at t = t₀, then



खुरदरे क्षैतिज पृष्ठ पर स्थित M द्रव्यमान व R त्रिज्या की एक समरूप डिस्क को t = 0 पर दर्शाए अनुसार वेग v₀ तथा कोणीय वेग ${\omega }_0=\frac{2v_0}{R}$ प्रदान किए जाते हैं। यह t = t₀ पर वेग v से शुद्ध लोटनिक गति प्रारम्भ करती है, तब

A charged particle having a charge of $-2.o\times {10}^{-6}C$ is placed close to a nonconducting plate having a surface charge density $4.0\times {10}^{-6}C{m}^{-2}$. Find the force of attraction between the particle and the plate.

A rocket is fired upward and its fuel is exhausted in $10\text{sec}$. The figure shows its $v–t$ graph, where $v$ is in $\text{m/s}$ and $t$ is in $\text{sec}$. What is the maximum height reached?

For a finite line charge, the net electric field at the non-axial point $\text{P}$ is directed toward the line $\text{PQ}$ where $\text{PQ}$ makes an angle $\theta$ with the axis of line charge. Find the value of $\theta$.

The length of a sonometer wire is $1.21\text{m}$. It is divided into three segments. What should be the lengths of the three segments for their fundamental frequencies to be in the ratio $1:2:3$?

A large cylindrical tank has a hole of area A at its bottom. Water is poured in the tank by a tube of equal cross-sectional area A ejecting water at the speed v.

(a) Estimate
the speed with which electrons emitted from a heated emitter of an
evacuated tube impinge on the collector maintained at a potential
difference of 500 V with respect to the emitter. Ignore the small
initial speeds of the electrons. The specific
charge of the electron, i.e., its e/m
is given to be 1.76 × 10¹¹
C kg⁻¹.

(b) Use the same
formula you employ in (a) to obtain electron speed for an collector
potential of 10 MV. Do you see what is wrong? In what way is the
formula to be modified?

A constant force F = $m_{2}g/2$ is applied on the block of mass $m_1$ as shown in figure. The string and the pulley are light and the surface of the table is smooth. The acceleration of $m_1$ is

A capacitor of capacitance $10\mu F$ is connected to a battery providing a potential difference of 10 V across the capacitor. The energy stored inside the capacitor is?

Total number of atoms present in $23\text{g}$ of $NaN{O}_2$ is:

$\text{Given: Atomic mass:}Na=23u,N=14u,O=16u{N}_A=6.023\times {10}^{23}$

If $|\overrightarrow{a}|=5,|\overrightarrow{b}|=3$ and $|\overrightarrow{a}\cdot \overrightarrow{b}|=10,$ then the value of $|\overrightarrow{a}\times \overrightarrow{b}|$ is

A uniform wire of resistance $R$ is cut into two equal pieces, and these pieces are joined in parallel. What is the equivalent resistance of the combination?

In a thermodynamic process, pressure of a fixed mass of gas is changed in such a manner that the gas releases $20\text{J}$ of heat and $8\text{J}$ of work is done on the gas. If initial internal energy of the gas was $30\text{J}$, then the final internal energy will be

A metre stick is balanced on a knife edge at its centre. When two coins, each of mass 5 g are put one on top of the other at the 12.0 cm mark, the stick is found to be balanced at 45.0 cm. What is the mass of the metre stick?

1. 25

A block of mass $m$ starts moving with an initial velocity $v_0$ at a distance $L$ towards a stationary spring of stiffness $K$ attached to the wall as shown in figure.

Find the distance travelled by block before coming to rest.
Given that surface is rough only for distance $L$ and friction coefficient $\mu$ is such that $(\frac{1}{2}m{v}_0^2>\mu mgL)$.

The value of ${\int }_1^5{x}^{2}dx$ is

The mass of the bob of a simple pendulum is ${}^{\prime }{m}^{\prime }$ and it carries a charge ${}^{\prime }{q}^{\prime }$. It oscillates in a uniform electric field $E$ as shown in the figure. Its time period will be

Two waves of equal frequencies have their amplitudes in the ratio of $3:5$. They are superimposed on each other. The ratio of maximum and minimum intensities of the resultant wave is

A guided support as shown in the figure below is represented by 3 springs (horizontal, vertical, and rotational) with stiffness $K_x,K_y,K_{\theta }$ respectively.

The limiting value of $K_x,K_y$ and $K_{\theta }$ are

A cylinder of mass 'm; is kept on the edge of a plank of mass '2m' and length 12 metre, which in turn is kept on smooth ground. Coefficient of friction between the plank and the cylinder is 0.1. The cylinder is given an impulse, which imparts it a velocity 7 m/s but no angular velocity. Find the time after which the cylinder falls off the plank.

Find the work done by the force in the given figure?

An electron, a proton and an alpha particle having the same kinetic energy are moving in circular orbits of radii $r_e,r_p,r_{\alpha }$ respectively in uniform magnetic field $B$. The relation between $r_e,r_p,r_{\alpha }$ is

Two sinusoidal plane waves of the same frequency having intensity $I_0$ and $4I_0$ are travelling in the same direction. The resultant intensity at a point at which waves meet with phase difference of zero radian is

A closed organ pipe can vibrate at a minimum frequency of 500 Hz. Find the length of the tube. Speed of sound in air = $340m{s}^{-1}$