Physics class tests for PUC, ISc, XII in the CBSE, ICSE (CISCE), State boards.

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Subject: Physics                                          

Test: Class test — III

Section A

Objective — 7 questions each carry 1 mark, all questions to be answered.

Question 1

Targets in X-ray tube are made of high atomic number metals. Examples are

A. Tungsten and Platinum              B. Nickel and Chromium

C. Uranium and Plutonium            D. Sodium and Mercury

Question 2

Electric and magnetic fields do not deflect which of the following

A. X-rays                    B. Y-rays

C. Electrons              D. Cosmic Rays

Question 3

Why  and  lines are produced — chose only one appropriate answer.

A. Electronic transitions                                                           B. Atomic collisions

C. Radioactive decay                                                                  D. Nuclear transmutation

Question 4

Exactly why there is quantization of physical variables such as momentum, angular momentum, energy, orbital distance and speed?

A. Wave-particle duality                                         B. Interference of waves

C. Particle acceleration to speed of light            D. Resistance experienced by particles in conductors

Question 5

Cathode rays are streams of

A. Electrons                                         B. X-rays

C. Nucleons                                          D. High atomic number elements

Question 6

Kirchhoff’s loop rule is based on?

A. Conservation of charge                 B. Conservation of energy

C. Conservation of baryon number D. Conservation of lepton number

Question 7

Kirchhoff’s junction rule is based on?

A. Conservation of charge                 B. Conservation of energy

C. Conservation of baryon and lepton number D. Conservation of azimuthal quantum number

Section B

Subjective — 14 questions carry 2 marks each, all to be answered.

Question 8

If threshold frequency is  Hz whats the work function of the metal in eV or joule?

Question 9

3 capacitors  each are in series, whats their equivalent resistance?

Question 10

3 capacitors  each are in parallel combination, whats their equivalent resistance?

Question 11

If a potential difference of  is applied at two ends of a long metal wire with current density  whats conductivity of the wire?

Question 12

In a Wheatstone bridge if  and  are the resistors in one arm, and what would the unknown resistor in the  arm be?

Question 13

If work function of a metal is  what would the maximum kinetic energy of any  be, given a light of energy of falls on the metal? Whats the stopping potential?

Question 14

Name 4 sources of electric power that can be harnessed for household applications.

Question 15

If 3 cells of emf  are connected in series with their + and – terminals connected in sequential order and each has a back-emf  whats the equivalent emf of the series?

Question 16

If a cell  and  are connected in parallel with zero internal resistance for both whats their equivalent emf?

Question 17

For principal quantum number whats the speed of an electron in a hydrogen atom?

Question 18

What would be the wavelength of a radiation of energy ?

Question 19

For a free electron of speed with  what is the de-Broglie wavelength?

Question 20

If a conductor of length and area of cross section  carries a current of , when a battery of emf with ideal terminal voltage  is connected across, what is the resistivity of the wire?

Question 21

In Thomson’s e/m experiment the  is going in a circle of circumference then whats the speed of the  if the magnetic field intensity B is where T ≡ Tesla, is SI unit of magnetic field intensity.