Simple Harmonic Motion — Physics STD 12 Science — Question

A capacitor acts as an infinite resistance for.

The wavelength of yellow line of sodium is 5896 Å. Its wave number will be

(a) 50883 × 1010 per second	(b) 16961 per cm
(c) 17581 per cm	(d) 50883 per cm

A parallel plate capacitor of capacitance C is connected to a battery and is charged to a potential difference V. Another capacitor of capacitance 2C is connected to another battery and is charged to potential difference 2V. The charging batteries are now disconnected and the capacitors are connected in parallel to each other in such a way that the positive terminal of one is connected to the negative terminal of the other. The final energy of the configuration is

(a) Zero

(b)

(c)

(d)

A light ray from air is incident (as shown in figure) at one end of a glass fiber (refractive index m = 1.5) making an incidence angle of 60^o on the lateral surface, so that it undergoes a total internal reflection.  How much time would it take to traverse the straight fiber of length 1 km

(a) 3.33 m sec

(b) 6.67 m sec

(c) 5.77 m sec

(d) 3.85 m sec

A circular loop of area 1cm², carrying a current of 10A, is placed in a magnetic field of 0.1T perpendicular to the plane of the loop. The torque on the loop due to the magnetic field is:

1. Zero
2. 10⁴N-m
3. 10²N-m
4. 1N-m

In a cathode ray tube, what is the effect on the beam of particles if the anode voltage is increased ?

Faraday's laws are consequence of conservation of

(a) Energy	(b) Energy and magnetic field
(c) Charge	(d) Magnetic field

The idea of the quantum nature of light has emerged in an attempt to explain

(a) Interference	(b) Diffraction
(c) Radiation spectrum of a black body	(d) Polarisation

When no current is passed through a conductor:

A star moves away from earth at speed 0.8 c while emitting light of frequency 6 . What frequency will be observed on the earth (in units of 10¹⁴ Hz) (c = speed of light)

(a) 0.24

(b) 1.2

(c) 30

(d) 3.3