Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then:

Which of the planet is brightest

(a) Mercury

(b) Venus

(c) Mars

(d) Jupiter

What is the reading of voltmeter in the following figure

(a) 3 V

(b) 2 V

(c) 5 V

(d) 4 V

At a certain place, the horizontal component  and the vertical component  of the earth's magnetic field are equal in magnitude. The total intensity at the place will be

(a)

(b)

(c)

(d)

A new flashlight cell of e.m.f. 1.5 volts gives a current of 15 amps, when connected directly to an ammeter of resistance 0.04Ω. The internal resistance of cell is

(a) 0.04 Ω

(b) 0.06 Ω

(c) 0.10 Ω

(d) 10 Ω

To charges  and  are placed 30 cm apart, shown in the figure. A third charge  is moved along the arc of a circle of radius 40 cm  from C  to D. The change in the potential energy of the system is , where k  is

(a) 8

(b)

(c)

(d)

SI unit of the magnetic field is _________.

If the following input signal is sent through a PN-junction diode, then the output signal across R_L will be

(a)

(b)

(c)

(d)

A constant current i is maintained in a solenoid. Which of the following quantities will increase if an iron rod is inserted in the soleniod along axis?

1. Magnetic field at the centre.
2. Mangetic flux linked with the solenoid.
3. Self-inductance of the solenoid.
4. Rate of Joule heating.

In Thomson experiment of finding e/m for electrons, beam of electron is replaced by that of muons (particle with same charge as of electrons but mass 208 times that of electrons). No deflection condition in this case satisfied if

(a) B is increased 208 times	(b) E is increased 208 times
(c) B is increased 14.4 times	(d) None of these