Question 4326:

• NECO 2000

Calculate the peak voltage of a mains supply of r.ms. value 220V.

A. 121 V
B. 156 V
C. 225 V
D. 240 V
E. 311 V

Question 4327:

• NECO 2000

Two 2.0Ω resistors can be combined circuit to give an overall resistance of ____________

A. 0.5Ω only
B. 1.0 Ω only
C. Either 0,5Ω or 1.0 Ω
D. Either 1.0Ω or 4.0 Ω
E. Either 0.5Ω, 1.0Ω or 4.0Ω

Question 4328:

• NECO 2000

An astronomical telescope which is being used to view a very distant object is said to be in normal adjustment if ____________

A. The final image is at the near-point
B. The image formed by the objective is before the focus of the eye piece
C. The angular magnification is the ratio of the focal length of the eye-piece lens to that of the objective
D. The foci dl the objective and the eye-piece coincide between the lenses
E. The distance between the objective lens and the eye-piece is equal to the difference between their focal lengths.

Question 4329:

• NECO 2000

A man standing 510m away from a wall sounds a whistle. The echo from the wall reaches him 3s later. Calculate the velocity of sound in air.

A. 170 ms-1
B. 340 ms-1
C. 680 ms-1
D. 765 ms-1
E. 1530 ms-1

Question 4330:

• NECO 2000

The image is a plane mirror is ____________

A. Inverted, real with a magnificant of \(\frac{1}{2}\)
B. Inverted, virtual with a magnification of 1
C. Inverted, real with a magnification of 2
D. Upright, virtual with a magnificent of 1
E. Upright, real with a magnification of 2