Electric Charges and Fields — Physics STD 12 Science — Question

The electron cannot exist inside the nucleus because:

A long thin hollow metallic cylinder of radius 'R' has a current i ampere. The magnetic induction 'B'-away from the axis at a distance r from the axis varies as shown in

(a)

(b)

(c)

(d)

Nucleus of an atom whose atomic mass is 24 consists of:

When ultraviolet rays are incident on metal plate, then photoelectric effect does not occurs. It occurs by the incidence of

(a) X-rays

(b) Radio wave

(c) Infrared rays

(d) Green house effect

The difference in the variation of resistance with temperature in a metal and a semiconductor arises essentially due to the difference in the

(a) Variation of scattering mechanism with temperature

(b) Crystal structure

(c) Variation of the number of charge carriers with temperature

(d) Type of bon

In the given figure the capacitors  have a capacitance 4mF each if the capacitor  has a capacitance 10mF, then effective capacitance between A and B will be

(a) 2mF

(b) 4mF

(c) 6mF

(d) 8mF

In the circuit shown here, the readings of the ammeter and voltmeter are

(a) 6 A, 60 V

(b) 0.6 A, 6 V

(c) 6/11 A, 60/11 V

(d) 11/6 A, 11/60 V

A conducting loop is placed in a uniform magnetic field with its plane perpendicular to the field. An emf is induced in the loop if:

1. It is translated.
2. It is rotated about its axis.
3. It is rotated about a diameter.
4. It is deformed.

When we remove polyester or woollen clothes in dark, we can see a spark and hear a crackling sound. Which of the following is responsible for it?