Physics

The balancing length for a cell is $560\mathrm{c}\mathrm{m}$ in a potentiometer experiment. When an external resistance of $10\mathrm{\Omega }$ is connected in parallel to the cell, the balancing length changes by $60\mathrm{c}\mathrm{m}$ . If the internal resistance of the cell is $\frac{N}{10}\mathrm{\Omega }$ , where $N$ is an integer then value of $N$  is

A particle $(m=1\mathrm{k}\mathrm{g})$  slides down a frictionless track (AOC) starting from rest of a point $A$  (height $2\mathrm{m}$  ). After reaching $C$ , the particle continues to move freely in air as a projectile. When it leading its highest point $\mathrm{P}$  (height 1 m  ) the kinetic energy of the particle (in J) is: (Figure drawn is schematic and not to scale (take $g=10{\mathrm{m}\mathrm{s}}^{-2}$  ) 

A $60\mathrm{p}\mathrm{F}$ capacitor is fully charged by a $20\mathrm{V}$ supply. It is then disconnected from the supply and is connected to another uncharged $60\mathrm{p}\mathrm{F}$ capacitor in parallel. The electrostatic energy that is lost in this process by the time the charge is redistributed between them is (in $\mathrm{n}\mathrm{J}$  )

A non-isotropic solid metal cube has coefficients of linear expansion as: $5*{10}^{-5}/{}^{\circ }\mathrm{C}$  along the $x=$  axis and $5*{10}^{-6}/{}^{\circ }\mathrm{C}$  along the $y$  and the $z$ -axis. If coefficient of volume expansion of the solid $\mathrm{C}*{10}^{-6}/{}^{\circ }\mathrm{C}$  then the value of $\mathrm{C}$  is                   

A loop ABCDEFA of straight edges has six corner points $A(\mathrm{0,0},0),B(\mathrm{5,0},0),C(\mathrm{5,5}$ , $0),D(\mathrm{0,5},0),E(\mathrm{0,5},5)$    and $F(\mathrm{0,0},5)$ . The magnetic field in this region in $\stackrel{?}{B}=(3\hat{i}+4\hat{k})T$ . The quantity of flux through the loop ABCDEFA (in Wb) is      

$\mathrm{M}$ grams of steam at  ${100}^{\circ }\mathrm{C}$ is mixed with $200\mathrm{g}$ of ice at its melting point in a thermally insulated container. If it produces liquid water at ${40}^{?}\mathrm{C}$ [heat of vaporization of water is $540\mathrm{c}\mathrm{a}\mathrm{l}/\mathrm{g}$ and heat of fusion of ice is $80\mathrm{c}\mathrm{a}\mathrm{l}/\mathrm{g}$ ], the value of $M$  is     

A Carnot engine operates between two reservoirs of temperatures $900\mathrm{K}$  and $300\mathrm{K}$ . The engine performs $1200\mathrm{J}$  of work per cycle. The heat energy (in J) delivered by the engine to the low temperature reservoir, in a cycle is

Consider a uniform cubical box of side a on a rough floor that is to be moved by applying minimum possible force $F$ at $a$ point $b$ above its centre of mass (see figure). If the coefficient of friction is $\mu =0.4$ , the maximum possible value of $100*\frac{b}{a}$  for box not to topple before moving is

A Carnot engine operates between two reservoirs of temperatures  and . The engine performs  of work per cycle. The heat energy (in J) delivered by the engine to the low temperature reservoir, in a cycle is

What is the significance of the direction in torque and angular momentum?