Physics 2009 Neco Past Questions and Answers

Question 26 :

• NECO 2009

A plane progressive wave is represented by the equation y = 0.2sin (200πt - 0.5.x) where x and y are measured in cm and t in s. What is the frequency of the wave?

A. 0.5Hz
B. 4.0Hz
C. 10.0Hz
D. 100.0Hz
E. 200.0Hz

Question 27 :

• NECO 2009

A transformer has an efficiency of 92.5%. the ratio number of turns in the primary coil to that in the secondary coil is 128 : 45. If the current passing through the secondary coil is 9.0A, calculate the current passing through the primary-coil.

A. 2.93A
B. 3.16A
C. 3.42A
D. 25.60A
E. 27.68A

Question 28 :

• NECO 2009

An immersion heater is rated 1500W. How long does it take the heater to raise the temperature of 1 kg of water by 30°C? (Assume heat lost to the surrounding is negligible, Specific heat capacity of water 4200Jkg^-1K^-1)

A. 84s
B. 112s
C. 130s
D. 168s
E. 280s

Question 29 :

• NECO 2009

The equation P^xV^yT^z = Constant is Charles’ law if

A. X = 0, y = 1 and z = -1
B. X = 0, y = -1 and z = 1
C. X = 1, y = 1 and z = 0
D. X = 1, y = 1 and z = -1
E. X = 1, y = 1 and z = 1

Question 30 :

• NECO 2009

When a resistor of resistance R is connected across a.c. the terminal p.d. of the cell is reduced to three-quart its e.m.f. The cell’s internal resistance in terms of R is ____________

A. \(\frac{R}{4}\)
B. \(\frac{R}{3}\)
C. \(\frac{R}{2}\)
D. 2\(\frac{R}{3}\)
E. R