What is the minimum wavelength of radiation required to detect a p-n junction diode made of a semiconductor having band gap 3.3 eV .
[Planck's constant $h=6.6 \times 10^{34} \mathrm{~J} . \mathrm{s}$ ]
$3300^{\circ} \mathrm{A}$
$4800^{\circ} \mathrm{A}$
$3750^{\circ} \mathrm{A}$
$7500^{\circ} \mathrm{A}$
A galvanometer of resistance $50 \Omega$ is having 30 divisions and a current sensitivity $10 \mathrm{~mA} /$ div. What should be the shunt resistance so that it can be converted into an ammeter of range 10 A ?
$0.76 \Omega$
$2.5 \Omega$
$1.55 \Omega$
$3.1 \Omega$
A block of mass 1.5 kg moves along the floor of a hall with a speed of $5 \mathrm{~ms}^{-1}$. It strikes an uncompressed spring and compresses it till the block becomes motionless. If the force constant of the spring is $10000 \mathrm{Nm}^{-1}$ and the spring is compressed by 5 cm , calculate the effective force of kinetic friction.
125 N
18.7 N
0
16.4 N
Find the current through the $40 \Omega$ resistor in the given circuit having a diode, three resistors and two cells.

0.21 A
0.5 A
1.2 A
2.1 A
COMEDK Papers
All year-wise previous year question papers