Question

A diffraction pattern is obtained by using a beam of red light. What will happen if the red light is replaced by the blue light. a. No change will take place. b. Bands become broader and farther apart. c. Bands disappear d. Diffraction bands become narrower and crowded.

To observe diffraction, the size of the obstacle (a) should be X/2, where X is the wavelength. (b) should be of the order of wavelength. (c) has no relation to wavelength. (d) should be much larger than the wavelength.

In which of the following forms is the energy stored in a capacitor? (a) Charge (b) Potential (c) Capacitance (d) Electric field

The colours on the soap bubble is due to (a) Interference (b) Diffraction (c) Polarisation (d) Reflection

A vertical disc of radius 10 cm makes 10 revolutions per second about a horizontal axis passing through its centre. A uniform magnetic field 10⁻² T acts perpendicular to the plane of the disc. The potential difference between its centre and rim in volts is (a) 3.14 × 10⁻² V (b) 3.14 × 10⁻³ V (c) 6.28 × 10⁻² V (d) 6.28 × 10⁻³ V

There is a uniform magnetic field directed perpendicular and into the plane of the paper. An irregular shaped conducting loop is slowly changing into a circular loop in the plane of the paper. Then, (a) Current is induced in the loop in the anti-clockwise direction (b) Current is induced in the loop in clockwise direction (c) AC Current is induced in the loop (d) No current is induced in the loop

A screen is placed 50m from a single slit, which is illuminated with 6000Å light. If the distancebetween the first and third minima in the diffraction pattern is 3.00mm, what is the width of the slit ? i. 200 µm ii. 300 µm iii. 250 µm iv. 350 µm