A wave completes 20 oscillations in 4 seconds. Frequency is MCQ with Answer and Explanation

Explanation:
F = m×a. New force F' = (2m)×(a/2) = m×a = F. So force remains unchanged. This is direct proportionality. Understand the relationship: doubling mass doubles force, halving acceleration halves it, net effect no change.

Explanation:
Nichrome high resistivity generates more heat, high melting point avoids melting at high temperature.

Explanation:
R_t = R₀(1+α t). 6 = 4(1+0.004 t) => 1.5 = 1+0.004t => 0.5=0.004t => t=125°C.