1
COMEDK 2026 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

The width of the fringes obtained with a light of wave length $6.2 \times 10^{-8} \mathrm{~m}$ is 1.82 mm . If the whole apparatus is immersed in a liquid of refractive index 1.3 , what will be the width of the resulting fringe?

A

1.4 mm

B

0.71 mm

C

2.8 mm

D

1.82 mm

2
COMEDK 2026 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

If $\mu_0$ is the permeability of free space and $\varepsilon_0$ permittivity of free space then the dimension for $\left(\mu_0 \varepsilon_0\right)^{1 / 2}$ is :

A

$\left[M L^{-1} T\right]$

B

$\left[M L T^{-1}\right]$

C

$\left[L^{-1} T\right]$

D

$\left[L^{-1} T^{-1}\right]$

3
COMEDK 2026 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

An electric field and magnetic field $1.8 \times 10^4 \mathrm{Vm}^{-1}$ and $6 \times 10^{-3} \mathrm{~T}$ respectively are applied simultaneously on an electron beam such that path of the beam remains undeviated, then the speed of the electron will be:

A

$1.5 \times 10^6 \mathrm{~ms}^{-1}$

B

$3 \times 10^7 \mathrm{~ms}^{-1}$

C

$3 \times 10^6 \mathrm{~ms}^{-1}$

D

$1.5 \times 10^7 \mathrm{~ms}^{-1}$

4
COMEDK 2026 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

Two point charges $P=+25 \mu C$ and $Q=-16 \mu C$ are placed 5 cm apart. Find the position of the point at which the resultant electric field is zero:

A

1 cm from $Q$ and 4 cm from $P$ on the dipole axis

B

2.5 cm from $Q$ and 2.5 cm from $P$ on the dipole axis

C

20 cm from $Q$ and 25 cm from $P$ on the dipole axis

D

25 cm from $Q$ and 20 cm from $P$ on the dipole axis