Ray Optics and Optical Instruments — Physics STD 12 Science — Question

If V be the accelerating voltage, then the maximum frequency of continuous X-rays is given by

(a)

(b)

(c)

(d)

A tangent galvanometer is connected directly to an ideal battery. If the number of turns in the coil is doubled the deflection will:

A current passes through a wire of non-uniform cross-section. Which of the following quantities are independent of the cross-section?

1. The charge crossing in a given time interval.
2. Drift speed.
3. Current density.
4. Free-electron density.

Which crystal is used in the Davisson – Germer experiment?

Five resistors of given values are connected together as shown in the figure. The current in the arm BD will be

(a) Half the current in the arm ABC	(b) Zero
(c) Twice the current in the arm ABC	(d) Four times the current in the arm ABC

In Young's double slit experiment, if monochromatic light is replaced by white light

(a) All bright fringes become white

(b) All bright fringes have colours between violet and red

(c) Only the central fringe is white, all other fringes are coloured

(d) No fringes are observed

Mark the correct options:

1. A diode valve can be used as a rectifier.
2. A triode valve can be used as a rectifier.
3. A diode valve can be used as an amplifier.
4. A triode valve can be used as an amplifier.

Which series of hydrogen atom's spectrum does not lie in infrared region ?

How will  the force between the two poles change if the two poles are connected by an iron rod keeping the distance between two magnetic poles constant ?

Waves in decreasing order of their wavelength are: