# What will be the wave velocity, if the radar gives 54 waves/min and wavelength of the given wave is 10 m?   1.  4 m/s   2.  6 m/s   3.  9 m/s   4.  5 m/s

A transformer of 100% efficiency has 200 turns in the primary coil and 40000 turns in secondary coil. It is connected to a 220 V main supply and secondary feeds to a 100 kΩ resistance. The potential difference per turn is

1.  1.1 V

2.  25 V

3.  18 V

4.  11 V
Subtopic:  Transformer |
59%
Hints

A thin convex lens of refractive index 1.5 has 20 cm focal length in air. If the lens is completely immersed in a liquid of refractive index 1.6, its focal length will be

1.  -160 cm

2.  - 100 cm

3.  + 10 cm

4.  +100 cm
Subtopic:  Lens Makers' Formula |
55%
Hints

SI unit of permittivity is

1.  C2m2N2

2.  C2m-2N-1

3.  C2m2N-1

4.  C-1m2N-2

Subtopic:  Coulomb's Law |
68%
Hints

A spherical drop of capacitance 1μF is broken into eight drops of equal radius. Then, the capacitance of each small drop is
1.   μF
2.   μF
3.   μF
4.  8 μF
Subtopic:  Capacitance |
52%
Hints

A simple harmonic oscillator consists of a particle of mass m, and an ideal spring with spring constantk. The particle oscillates with a time period T. The spring is cut into two equal parts, Of one part oscillates with the same particles, the time period will

1.  2T

The coefficient of viscosity for hot air is

1.  greater than the coefficient of viscosity for cold air

2.  smaller than the coefficient of viscosity for cold air

3.  same than the coefficient of viscosity for cold air

4.  increase than the coefficient of viscosity for cold air

Subtopic:  Viscosity |
Hints

An artificial satellite moving in a circular orbit around the earth has a total (kinetic + potential) energyE0. Its potential energy is
1.  -E0

Subtopic:  Satellite |
64%
Hints

A thin hollow sphere of mass m is completely filled with a liquid of mass m. When the sphere rolls with a velocity v, kinetic energy of the system is (neglect friction)

1.  mv2

A non-conducting body floats in a liquid at 20 °C with of its volume immersed in the liquid. When liquid temperature is increased to 100 °C, of body’s volume is immersed in the liquid. Then the coefficient of real expansion of the liquid is (neglecting the expansion of container of the liquid)