Question

Light is an electromagnetic wave. Its speed in vacuum is given by the expression

(a)  

(b)

(c)     

(d)

Answer

(d)

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A positively charged particle moving due east enters a region of uniform magnetic field directed vertically upwards. The particle will

(a) Get deflected vertically upwards

(b) Move in a circular orbit with its speed increased

(c) Move in a circular orbit with its speed unchanged

(d) Continue to move due east

A metallic rod of length $l$ is kept perpendicular to a magnetic field and it is rotated on a circular path with frequency $f$. The potential difference across the ends of the rod is :

The rest mass of an electron as well as that of positron is 0.51 MeV. When an electron and positron are annihilate, they produce gamma-rays of wavelength(s)

(a) 0.012 Å

(b) 0.024 Å

(c) 0.012 Å to ¥

(d) 0.024 Å to ¥

In the given figure, battery E is balanced on 55 cm length of potentiometer wire but when a resistance of 10 W is connected in parallel with the battery then it balances on 50 cm length of the potentiometer wire then internal resistance r of the battery is

(a) 1 W

(b) 3 W

(c) 10 W

(d) 5 W

Identify the logic gate in figure.

Which of the following contains a covalent bond?

When an electron in hydrogen atom is excited, from its 4th to 5th stationary orbit, the change in angular momentum of electron is (Planck’s constant: h = 6.6  

(a) 4.16   

(b) 3.32  

(c) 1.05  

(d) 2.08  

Plane polarised light is passed through a polaroid. On viewing through the polaroid we find that when the polariod is given one complete rotation about the direction of the light, one of the following is observed

(a) The intensity of light gradually decreases to zero and remains at zero

(b) The intensity of light gradually increases to a maximum and remains at maximum

(c) There is no change in intensity

(d) The intensity of light is twice maximum and twice zero

A permanent magnet

(a) Attracts all substances

(b) Attracts only magnetic substances

(c) Attracts magnetic substances and repels all non-magnetic substances

(d) Attracts non-magnetic substances and repels magnetic substances

The magnitude of magnifying power of an astronomical telescope is 5, the focal power of its eyepiece is 10 diopters. The focal power of its objective (in diopters) is: