1
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

If an electron in a hydrogen atom jumps from the third orbit to the second orbit, it emits a photon of wavelength $$\lambda$$. When it jumps from the second to the first orbit, the corresponding wavelength of the photon will be

A
$$ \frac{5 \lambda}{27} $$
B
$$ \frac{7 \lambda}{20} $$
C
$$ \frac{16 \lambda}{9} $$
D
$$ \frac{20 \lambda}{7} $$
2
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

A solid cylinder of mass $$2 \mathrm{~kg}$$ and radius $$0.2 \mathrm{~m}$$ is rotating about its own axis without friction with angular velocity $$5 \mathrm{~rad} \mathrm{s}^{-1}$$. A particle of mass $$1 \mathrm{~kg}$$ moving with a velocity of $$5 \mathrm{~ms}^{-1}$$ strikes the cylinder and sticks to it as shown in figure.

COMEDK 2024 Evening Shift Physics - Rotational Motion Question 1 English

The angular velocity of the system after the particle sticks to it will be

A
$$ 15.0 \mathrm{~rad~s}^{-1} $$
B
$$ 12.0 \mathrm{~rad~s}^{-1} $$
C
$$ 10.0 \mathrm{~rad~s}^{-1} $$
D
$$ 30.0 \mathrm{~rad~s}^{-1} $$
3
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

A neutral water molecule is placed in an electric field $$E=2.5 \times 10^4 \mathrm{NC}^{-1}$$. The work done to rotate it by $$180^{\circ}$$ is $$5 \times 10^{-25} \mathrm{~J}$$. Find the approximate separation of centre of charges.

A
$$1.25 \times 10^{-10} \mathrm{~m}$$
B
$$0.625 \times 10^{-10} \mathrm{~m}$$
C
$$0.625 \times 10^{-9} \mathrm{~m}$$
D
$$0.998 \times 10^{-10} \mathrm{~m}$$
4
COMEDK 2024 Evening Shift
MCQ (Single Correct Answer)
+1
-0

A telescope has an objective of focal length $$60 \mathrm{~cm}$$ and eyepiece of focal length $$5 \mathrm{~cm}$$. The telescope is focussed for least distance of distinct vision $$300 \mathrm{~cm}$$ away from the object. The magnification produced by the telescope at least distance of distinct vision is

A
+1.5
B
+2
C
$$-$$1.5
D
$$-$$2
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12