Question 841:

• JAMB 1995

A light of energy 5eV falls on a metal and the electrons with a maximum kinetic energy of 2eV are ejected. The work function of the metal is

A. 0.4eV
B. 2.5eV
C. 3.0eV
D. 7.0eV

Question 842:

• JAMB 1995

The half-life of a radio-active element is 9 days, what fraction of atoms has decayed in 36 days?

A. \( \frac{1}{16} \)
B. \( \frac{1}{4} \)
C. \( \frac{1}{2} \)
D. \( \frac{15}{16} \)

Question 843:

• JAMB 1995

An alternating source is connected in series to a capacitor of capacity reactance \( 10^3 \sqrt{3} \) and a resistor of resistance 10³ Ohms. The Impedance of the circuit is...

A. \( 2000 \sqrt{3} \) Ohms
B. 2000 Ohms
C. \( 1000 \sqrt{3} \) Ohms
D. 1000 Ohms

Question 844:

• JAMB 1995

In the above fig, PQ and R are vectors, which of the following options, gives a correct relationship between the vectors

A. P = Q + R
B. P = Q - R
C. P = R - Q
D. P + Q + R = O

Question 845:

• JAMB 1995

The value of T in the figure above is

A. 10.0N
B. 11.8N
C. 20.0N
D. 40.0N