Explanation

Kinetic Energy = 1/2 x m x v^2

m of electron = 9.1 x 10^-31 kg

v = 10^6 m/s

KE = 0.5 x 9.1 x 10^-31 x (10^6)^2

KE = 0.5 x 9.1 x 10^-31 x 10^12

KE = 4.55 x 10^-19 J

Convert J to eV:

1 eV = 1.6 x 10^-19 J

Energy in eV = 4.55 x 10^-19 / 1.6 x 10^-19

Energy = 2.84 eV

Last verified on 03-11-2026

Explanation

First Law: Delta U = Q + W

Where W = work done ON the system

Delta U = -300 J (decreases)

W = +120 J (work done ON the system)

-300 = Q + 120

Q = -300 - 120

Q = -420 J

Negative sign means 420 J heat is released from the system / heat is transferred out of the system.

Last verified on 03-11-2026

Explanation

• Solid-state detectors detect ionizing radiation by producing electrical signals when radiation interacts with semiconductor material.
• Wilson cloud chambers make the tracks of charged particles visible, helping identify their paths and behaviour.
• Geiger tubes detect ionizing radiation by producing electrical pulses, but they do not directly measure the mass or charge of a particle.

Last verified on 03-11-2026

Explanation

• Cobalt-60 is a radioactive isotope that emits high-energy gamma rays.
• These gamma rays are used in radiotherapy to destroy cancer cells by damaging their DNA.
• Cobalt-60 has been widely used in external-beam cancer treatment, although modern radiotherapy also uses linear accelerators.

Last verified on 03-11-2026

Explanation

• A transistor operates when it is properly biased and a suitable voltage is applied across its terminals.
• In a bipolar junction transistor (BJT), the emitter injects charge carriers into the base region.

Last verified on 02-11-2026

Explanation

• A lattice array is a regular, repeating arrangement of points representing the positions of atoms, ions, or molecules in a crystal.

Additional information:

• A unit cell is the smallest repeating structural unit that can generate the entire crystal lattice.
• A lattice constant is a parameter describing the dimensions of the unit cell, such as its edge lengths.

Last verified on 02-11-2026

Explanation

Displacement is shortest distance from start to end.

It forms a right angle triangle.

North = 20 Km

East = 10 Km

Formula: Displacement = sqrt( (20)^2 + (10)^2 )

Displacement = sqrt( 400 + 100 )

Displacement = sqrt( 500 )

Displacement = 22.36 Km

Last verified on 02-11-2026

Explanation

Accuracy is decided by least count. Smaller least count means more accurate instrument.

2.0 gm -> least count 0.1 gm

20.0 gm -> least count 0.1 gm

0.0002 gm -> least count 0.0001 gm

Least count of 0.0002 gm is smallest (0.0001 gm), so its absolute error is smallest.

So it is measured by most precise instrument, so it is most accurate.

Last verified on 02-11-2026

Explanation

Formula: e = L x dI/dt

e = 200 V

dI = 5 - 0 = 5 A

dt = 0.1 sec

L = e x dt / dI

L = 200 x 0.1 / 5

L = 20 / 5

L = 4 H

Last verified on 02-11-2026

Explanation

Ig = 0.2 A (galvanometer current)

Rg = 10 ohm

I = 1.8 A (total current)

Current through shunt Is = I - Ig

Is = 1.8 - 0.2 = 1.6 A

Formula: Ig x Rg = Is x Rs

Rs = Ig x Rg / Is

Rs = 0.2 x 10 / 1.6

Rs = 2 / 1.6

Rs = 1.25 ohm

Last verified on 02-11-2026