A simple pendulum has a time period T when on the earth's surface and T₂ when taken to a height 2R above the earth's surface where R is the radius ofthe earth. The value of (T₁ /T₂) is

• $\frac{1}{9}$

• $\frac{1}{3}$

• 3

• 9

The readings of a constant volume gas thermometer at 0°C and 100°C are 40 cm of mercury and 60 cm of mercury. If its reading at an unknown temperature is 100 cm of mercury column, then the temperature is 

• 100°C

• 50°C

• 25°C

• 300°C

In a cubic unit cell of bcc structure, the lattic points (i.e., number of atoms) are

• 2

• 6

• 8

• 12

A 2 kg copper block is heated to 500°C and then it is placed on a large block of ice at 0°C. If the specific heat capacity of copper is 400 J kg^-1°C^-1 and latent heat of fusion of water is 3.5 x 10⁵ J kg^-1 the amount of ice that can melt is

• 7/8 kg

• 7/5 kg

• 8/7 kg

• 5/7 kg

Two identical springs, each of spring constant K, are connected first series and then in parallel. A mass M is suspended from them. The ratio of the frequencies of vertical oscillations will be

• 2 : 1

• 1 : 1

• 1 : 2

• 4 : 1

A solid sphere of volume V and density ρ floats at the interface of two immiscible liquids of densities ρ₁ and ρ₂ respectively. If ρ₁ < ρ₂, then the ratio of volume of the parts of the sphere in upper and lower liquids is 

• $\frac{\mathrm{\rho } - {\mathrm{\rho }}_2}{{\mathrm{\rho }}_1 - \mathrm{\rho }}$

• $\frac{{\mathrm{\rho }}_2 - \mathrm{\rho }}{\mathrm{\rho } - {\mathrm{\rho }}_1}$

• $\frac{\mathrm{\rho } + {\mathrm{\rho }}_1}{\mathrm{\rho } + {\mathrm{\rho }}_2}$

• $\frac{\mathrm{\rho } + {\mathrm{\rho }}_2}{\mathrm{\rho } + {\mathrm{\rho }}_1}$

At a temperature of 30°C, the susceptibility of a ferromagnetic material is found to be χ. Its susceptibility at 333°C is 

• χ

• 0.5 χ

• 2 χ

• 0.09 χ

Two identical air core capacitors are connected in series to a voltage source of 15 V. If one of the capacitors is filled with a medium of dielectric constant 4, the new potential across this capacitor is

• 5 V

• 8 V

• 10 V

• 12 V

39.

In co-axial cable the material used as spacer is

• teflon (or) polyethylene

• glass or mica

• a gaseous medium

• glass

Two identical cells whether connected in parallel or in series gives the same current when connected to an external resistance 1.5 Ω. Find the value of internal resistance of each cell.

• 1 Ω

• 0.5 Ω

• 1.5 Ω

• zero