MHT-CET PCB 06 — MHT - CET STD 12 Science — Question

An electron(e) is revolving in a circular orbit of radius r in the hydrogen atom. The angular momentum of the electron is (M = magnetic dipole moment associated with it and m = mass of electron)

Select the WRONG statement:

Van de Graaff generator produces ______.

A metal rod of length Land cross-sectional area A is heated through T °C. What is the force required to prevent the expansion of the rod lengthwise?

(Y = Young's modulus of material of the rod, α = coefficient of linear expansion of the rod.)

Match the column I (PCR steps) and Column II (Temperature). Select the correct option.

	Column I (PCR steps)		Column II (Temperature)
i.	Polymerization	P.	40 - 60°C
ii.	Denaturation	Q.	70 - 75°C
iii.	Primer annealing	R.	90 - 98°C
		S.	28 - 37°C

If line joining points A and B having position vectors `6overlinea - 4overlineb + 4overlinec` and `-4overlinec` respectively, and the line joining the points C and D having position vectors `-overlinea - 2overlineb - 3overlinec` and `overlinea + 2overlineb - 5overlinec` intersect, then their point of intersection is ______

Which of the following is TRUE about molecular solids?

A sample of gas absorbs 4000 kJ of heat and surrounding does 2000 J of work on sample. What is the value of ∆U?

Which part of the root helps in the maximum absorption of water and minerals?