Atoms — Physics STD 12 Science — Question

The curve of binding energy per nucleon as a function of atomic mass number has a sharp peak for helium nucleus. This implies that helium?

Two batteries, one of emf 18 volts and internal resistance 2Ω and the other of emf 12 volt and internal resistance 1 Ω, are connected as shown. The voltmeter V will record a reading of

(a) 15 volt

(b) 30 volt

(c) 14 volt

(d) 18 volt

16 gm sample of a radioactive element is taken from Bombay to Delhi in 2 hour and it was found that 1 gm of the element remained (undisintegrated). Half life of the element is

(a) 2 hour

(b) 1 hour

(c)

(d)

If the distance between the plates of parallel plate capacitor is halved and the dielectric constant of dielectric is doubled, then its capacity will

(a) Increase by 16 times	(b) Increase by 4 times
(c) Increase by 2 times	(d) Remain the same

When is the effective capacitance of a capacitor increased?

A slab X is placed between the two parallel isolated charged plates as shown in the figure. If E_p​ and E_q​ denotes the intensity of electric field at P and Q, then:

The magnetic field in a coil of 100 turns and 40 square cm area is increased from 1 Tesla to 6 Tesla in 2 second. The magnetic field is perpendicular to the coil. The e.m.f. generated in it is

(a)

(b) 1.2 V

(c) 1.0 V

(d)

Consider telecommunication through optical fibres. Which of the following statements is not true

(a) Optical fibres may have homogeneous core with a suitable cladding

(b) Optical fibres can be of graded refractive index

(c) Optical fibres are subject to electromagnetic interference from outside

(d) Optical fibres have extremely low transmission loss

The current in the given circuit is

(a) 0.1 A

(b) 0.2 A

(c) 0.3 A

(d) 0.4 A