A motorcyclist rides onto a road at 22.2 m/s at 12:00 noon and maintains that speed for the rest of her journey. At 12:01 a car travelling at 27.8 m/s turns onto the road at the same point as did the motorcycle. How many seconds after the motorcycle started will it be passed by the car?

1) 48 sec
2) 102 sec
3) 298 sec
4) 78 sec

A concave mirror is placed over a beaker containing water of (µ = 1.33) and image of the object placed at the bottom of beaker is formed at a distance of 25 cm from the top then focal length of the mirror is

In the basic $$\displaystyle CsCl$$ crystal structure, $$\displaystyle { Cs }^{ + }$$ and $$\displaystyle { Cl }^{ - }$$ ions are arranged in a bcc configuration as shown in the figure. The net electrostatic force exerted by the eight $$\displaystyle { Cs }^{ + }$$ ions on the $$\displaystyle { Cl }^{ - }$$ ion is : 

1) $$\displaystyle \frac { 1 }{ 4\pi { \varepsilon }_{ 0 } } \frac { 4{ e }^{ 2 } }{ 3{ a }^{ 2 } } $$

2) $$\displaystyle \frac { 1 }{ 4\pi { \varepsilon }_{ 0 } } \frac { 16{ e }^{ 2 } }{ 3{ a }^{ 2 } } $$

3) $$\displaystyle \frac { 1 }{ 4\pi { \varepsilon }_{ 0 } } \frac { 32{ e }^{ 2 } }{ 3{ a }^{ 2 } } $$

4)$$\displaystyle zero$$

 If solar temp. is doubled then :

(1) it will emit infra red rays mainly

(2) it will emit ultra vilet rays mainly

(3) emission will be doubled

(4) emission will be four times

A fully charged capacitor has a capacitance $$C$$. It is discharged through a small coil of resistance wire, embedded in a block of specific heat $$s$$ and mass $$m$$ under thermally isolated conditions. If the temperature of the block is raised by $$\displaystyle \Delta T$$, the potential difference $$V$$ across the capacitor initially is: 

1) $$\displaystyle { \left( \frac { 2ms\Delta T }{ C } \right) }^{ 2 }$$

2) $$\displaystyle { \left( \frac { 2ms\Delta T }{ C } \right) }^{ 1/2 }$$

3) $$\displaystyle { \left( \frac { 2ms\Delta T }{ C } \right) }$$

4) $$\displaystyle 2ms\Delta TC$$

The 6563 ?A Hα line emitted by hydrogen in a star is found to be red-shifted by 15 A?. Estimate the speed with which the star is receding from the Earth.

1) 68.6×10⁵ms−1
2) 2.86×10⁵ms⁻¹
3) 6.86×10⁵ms−1
4) 1.86×10⁵ms−1

A solenoid has an inductance L. A second solenoid is identical to the first except that it is twice as large; it is magnified by a factor of two. What is the ratio of the inductance of the magnitude inductor to the original inductor?

1) 4
2) 2
3) 1
4) 1/2

Two planets of radii R₁ and R₂ have the same density. The ratio of their accelerations due to gravity at the surface is

1)  (R₂ /R₁)²
2) R₂ /R₁
3) (R₁ /R₂)²
4) R₁ /R₂

An object is projected up wards with velocity of 100 m/sec. it will strike the ground in approximately ( g=10 m/sec2)
1) 10 sec
2) 5 sec
3) 15 sec
4) 20 sec

In a Youngs double-slit experiment, the slits are separated by 0.28 mm and the screen is placed 1.4 m away. The distance between the central bright fringe and the fourth bright fringe is measured to be 1.2 cm. Determine the wavelength of light used in the experiment.

1) 400nm
2) 200nm
3) 600nm
4) 100nm