Fill in the Blanks:
The length of the longest piece of string that can e strectched straight in a rectangular room whose dimensins are 10,13 and 8 units is ……….

The length of the longest pole that can be put in a room of dimensions (10mxx10mxx5m) is

Find the length of the longest rod that can be placed in a room 12 m long 9 m broad and 8 m high.

We would like to prepare a scale whose length does not change with temperature. It is proposed to prepare a unit scale of this type whose length remains, say 10 cm. We can use a bimetallic strip made of brass and iron each of different length whose length (both components) would change in such a way that difference between their lengths remains constant. If alpa_(iron = 1.2 xx 10^-5 //K and alpha_(brass = 1.8 xx 10^-5//K , what should we take as length of each strip?

A small ball of mass 2 xx 10^-3 kg, having a charge 1 mu C, is suspended by a string of length 0.8 m. Another identical ball having the same charge is kept at the point of suspension. Determine the minimum horizontal velocity that should be imparted to the lower ball so that it can make a complete revolution.

The density of air in atmoshpere decreases with height and can be expressed by the relaton rho = rho_0e^(-alphah where rho_0 is the density at sea level , alpha is a constant and h is the height, Calculate the atmospheric pressure at sea level. Assume g to be constatn. The numerical values of constants are : g = 9.8 ms^-2 , rho_0 = 1.3 kg m^-3 , alpha = 1.2 xx 10^-4 m^-1

A small retangular coil ABCD contains 140 turns of wire. The sides AB and BC of the coil are of length 4.5 and 2.8 cm respectively, as shown in the figure The coil is held between the poles of a large magnet so that the coil can rotate about an axis thorugh its centre. The magnet produces a uniform magnetic field of flux density B between its poles. When the current in the coil is 170 mA, the maximum torque produced in the coil is 2.1 xx 10^-3 N m . The current in the coil in (a) is switched off and the coil s positioned as shown in the figure. The coil is then turned thorugh an angle of 90^@ in a time of 0.14 s. Calculate the average e.m.f. induced in the coil.

Take 36 cubes of equal sizes (i.e., length of each cube is same). Arrange them to form a cuboid. You can arrange them in many ways. Observe the following table and fill in the blanks. What do you observe?

The well known mineral fluorite is chemically clacium fluoride. Its is known that in one unit cell of this mineral there are 4 Ca^(2+) ions and 8 F^- ions and that of Ca^(2+) ions are arranged in a fcc lattice. The F^- ions fill all the tetrahedral holes in the face centred cubic lattice of Ca^(2+) ions. the edge of hte unit cell is 5.46xx10^-8 cm in length. the density of the solid is 3.18 gcm^-3 . use this information to calculate the Avagadro's number. (Molar mass of CaF_2=70.08 g mol^-1 ).