31.

Which of the following has maximum property of elasticity?

• Rubber

• Lead

• Wood

• Steel

If temperature of an object is 140°F, then its temperature in centrigrade is

• 105°C

• 32°C

• 140°C

• 60°C

Temperature of a piece of silicon is raised from 27°C to 100°C, then its conductivity

• increases

• decreases

• remains same

• becomes zero

Three capacitors of 3, 2 and 6 µF are connected in series with a battery of 10 V. Then charge on 3 µF capacitor will be

• 10 µC

• 12 µC

• 14 µC

• 5 µC

Equivalent capacity between A and B is

• 2 µF

• 3 µF

• 4 µF

• 0.5 µF

Power factor of L-C-R circuit in resonation condition is

• 1

• $\frac{1}{2}$

• zero

• $\frac{1}{\sqrt{2}}$

An inductor and a capacitor are connected in an AC circuit inductance and capacitance are 1 H and 25 µF, then for maximum current, angular frequency will be (circuit is connected in series)

• 200 rad/s

• 50 rad/s

• 100 rad/s

• 150 rad/s

Spectrum of a star is shifting towards voilet colour, then the star

• is going away from earth

• is coming towards earth

• intensity of light of star is increasing

• intensity of light of star is decreasing

Susceptibility of a magnetic field is

• $\mathrm{{\rm X}} = \frac{\mathrm{l}}{\mathrm{H}}$

• $\mathrm{{\rm X}} = \frac{\mathrm{B}}{\mathrm{H}}$

• $\mathrm{{\rm X}} = \frac{\mathrm{M}}{\mathrm{V}}$

• $\mathrm{{\rm X}} = \frac{\mathrm{M}}{\mathrm{H}}$

Work of invertor is

• to change AC into DC

• to change DC into AC

• to regulate voltage

• None of the above