Time :1 hour

Attempt all questions.

Attempt all questions.

- The focal length of a lens is 30cm and the size of the image is a quarter of the object, then the object distance is
- 90cm
- 60cm
- 30cm
- 40cm

- A car travelling at 30ms
^{-1}decelerates uniformly to rest in a distance of 60m. If the driver has a mass of 80kg, which one of the following is the average retarding force in newtons necessary to retain him in his seat?- 150
- 300
- 600
- 1200

- Refractive index of a material depends on
- Angle of the prism
- Wavelength of the light
- Intensity of light
- Frequency of light

- A body is acted on by forces X, Y, and Z that it in equilibrium. X is 5N, Y is 4N and zis 3N what is the angle between the direction of X and Z?
- 37 degrees
- 53degrees
- 90degrees
- 127degrees

- Under certain conditions, the rate of cooling of a given body is directly proportional to the difference between its temperature and that of its surroundings. The rate of cooling of the body is 12Kmin
^{-1}when the temperature is 60^{0}C. The surrounding temperature,in^{0}C, is- 10
- 20
- 30
- 40

- Optical fibres are based on the principle of
- successive reflections
- refraction
- total internal reflection
- scattering

- The capacitance of a parallel plate capacitor increases with the
- decreases of its area
- increase of its distance
- increase of its area
- none of the above

- A train is travelling at a a constant speed of 25ms
^{-1}along a straight level track. As it a point P,a constant braking force is applied and the train comes to rest at a distance 500m from P. On another occasion, the same train travelling at 50ms^{-1}is subject to the same constant braking force applied at the same point. All other forces may be neglected. On this occasion, the train comes to rest at a distance in m from P of- 250
- 500
- 1000
- 2000

- A constant volume gas thermometer indicates a pressure of 20kpa when in thermal equilibrium at 273K. When in thermal equilibrium with a steam bath at a temperature of 100
^{0}C the thermometer will indicate a pressure, in kpa, of approximately- 54
- 27
- 14
- 7

- Two identical spheres are joined in parallel, charged to a potential V and then separated and then connected in series
- The charges on free plates are enhanced
- The charges stored in system increases
- The energy stored in the system increases
- Potential difference in free plates is 2V

- A parallel plate capacitor is made with air as medium between the plates has a capacitance of 10microfarads. The area of the capacitor is divided into two equal halves and filled with two media having dielectric constants K
_{1}=1 and k_{2}= 4. The capacitance of the system will now be- 10microfarad
- 20microfarad
- 40microfarad
- 30microfarad

- A block of ice, mass 1.5kg, absorbs thermal energy from its surroundings at a steady rate of 50W. The specific latent heat of fusion is 3.0 x 10
^{5}Jkg^{-1}. The time in hours ,for the ice to melt is- 150
- 100
- 3.75
- 2.50

- A body of mass 4kg falls vertically through air. When the magnitude of the air resistance is 30N, what is the acceleration of the body?
- 17.5ms
^{-2} - 7.5ms
^{-2} - 2.5ms
^{-2} - 0.4ms
^{-2}

- 17.5ms
- A crane has a maximum safe working load of 1200kg and is used to lift a concrete block of mass 1000kg. What is maximum safe upwards acceleration of the block whilst being lifted?
- 0.20ms
^{-1} - 0.85ms
^{-1} - 1.2ms
^{-1} - 2.0ms
^{-1}

- 0.20ms
- A lunar landing module is descending to the moon's surface at a steady velocity of 10ms
^{-1}. At a height of 120m, a small object falls from its landing gear. Taking the moon's gravitational acceleration as 1.6ms^{-2}, at what speed in ms^{-1}does the object strike the moon?- 202
- 22
- 19.6
- 16.8

- Which one of the following is the correct unit for specific latent heat of fusion?
- Jkg
^{-1} - Wkg
^{-1} - Jkg
^{-1}K^{-1} - Jk
^{-1}

- Jkg
- A parallel plate is capacitor is made by stacking n equally spaced parallel plates connected alternatively. if the capacitor between any two plates is C, then the resultant capacitance of the system will now be
- Cmicrofarads
- ncmicrofarads
- (n-1)microfarads
- (n+1)microfarads

- A dielectric slab of dielectric constant 5 is covered from all sides with a metallic foil. The system is introduced into the space of a parallel plate capacitor of capacitance 10microfarad. The slab fills almost the almost the entire space between the plates but does not touch. The capacitance will become nearly
- infinity
- 50picofarad
- 2picofarads
- Zero

- A sky -diver has a mass of 80kg. The sky -diver attains a vertical speed 30ms
^{-1}, shortly after stepping from an aircraft. During this period the sky -diver falls 100m.What is the mean force of air resistance experienced by the sky -diver during this part of the fall?- 220N
- 400N
- 440N
- 800N

- A number of capacitors each of capacitor 1 microfarad and each one of which gets punctured if the potential difference just exceeds 500V is applied, are provided. The an arrangement suitable for giving a capacitance of 2microfarads across which 3000V may be applied, requires atleast
- 72 capacitors
- 6 capacitors
- 12 capacitors
- 2 capacitors

- A hollow metal sphere of radius 10cm is charged such that the potential on its surface is 80V. The potential at the centre of the sphere.
- 800V
- 80V
- 8V
- zero

- At sunrise or sun set the sun looks more red than at mid - day, because
- the sun is hottest at these times
- of the scattering of light
- of the effects of refraction
- of the effects of diffraction

- For an astronault in space, the sky appears
- white
- green
- blue
- black

- An achromatic doublet is formed by joining
- 2 convex lenses
- 2 concave lenses
- 1 convex and 1 concave lens
- 1 convex and 1 plane

- A body of mass 4kg is is accelerated from rest from rest by a steady force of 9N. What is its speed when it has travelled a distance of 8m?
- 3.6ms
^{-1} - 4.5ms
^{-1} - 6.0ms
^{-1} - 18.0ms
^{-1}

- 3.6ms
- Which thermodynamic temperature is equivalent to 501.85
^{0}C?- 775.00K
- 774.85K
- 228.85K
- 228.70K

- A car travelling at 30ms
^{-1}decelerates uniformly to rest in a distance of 60m. If the driver has a mass of 80kg, which one of the following is the average retarding force, in newtons , necessary to retain him in his seat?- 150
- 300
- 600
- 1200

- A force of 3800N is required to move a vehicle of mass 1500kg at a constant speed along a horizontal road. In travelling 300m along the road, the work in KJ, done against frictional forces is
- 12.7
- 450
- 1140
- 5700

- There are two +1microcoulombs and 5microcoulombs. The ratio of the forces acting on them will be
- 1:5
- 1:1
- 5:1
- 1:25

- The twinkling of stars is due to
- the fact that stars do not emit light continuously
- The refractive index of the earth's atmosphere fluctuates
- Intermittent absorption of star light by its own atmosphere
- none of these